Master thesis - Indoor environment in a digital future

INDOOR ENVIRONMENT IN A DIGITAL FUTURE
Data Collection, Analysis and Visualisation
Keywords: IEQ, productivity, IoT devices, data visualisation.
Masters Thesis in Architectural Engineering
July, 2020
By
Feodora Olivia Frisesdal - s153767
Rebekka Katrine Pallesen - s154397
Supervisor
Jørn Toftum, Professor - Department of Civil Engineering
Co-supervisor
Emilie Patricia Dam-Krogh, PhD student - Department of Civil Engineering
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Feodora Olivia Frisesdal
DTU, Department of Civil Engineering, Brovej, Building 118, 2800 Kgs. Lyngby Denmark
www.byg.dtu.dk

Preface
This Master thesis has been prepared over five months at the Section for Indoor Environment
Department of Civil Engineering, at the Technical University of Denmark, DTU, in partial fulfilment
for the degree Master of Science in Architectural Engineering. The project is credited 32.5 ECTS
points.
Despite some complications related to COVID-19, we are glad, grateful and proud of the final
outcome of this master thesis. The process of writing this thesis would not have been as interesting
and educative without valuable contribution from different people.
We would therefore like to thank our supervisor Professor Jørn Toftum for always making time to
provide us with feedback and advise us. We would also like to thank our co-supervisor PhD.
student Emilie Patricia Dam-Krogh for the investment in our project and understanding of our
creative aspects and visual ideas.
Furthermore, we would like to thank the two companies, who allowed us to perform IEQ investigations
in their offices and for filling in our questionnaires. In addition to this, thank you to Jesper
Dyhr and Ole Hansen from Expan, and Niels Peter Frisesdahl and Hans Jørgen Frisesdahl from
Frisesdahl A/S for sharing information about challenges related to renovation and participating
in our feedback sessions.
Kongens Lyngby, July 15, 2020
Feodora Olivia Frisesdal
Rebekka Katrine Pallesen

Abstract
Poor indoor environment quality (IEQ) can cause health issues, allergies, discomfort, lack of
concentration, fatigue, and many other issues. In office environments, poor IEQ and its related
symptoms can result in both reduced productivity and reduced ability to work. The costs caused
by and related to poor IEQ include, but are not limited to, medical treatments, loss of work, and
lowered productivity.
Buildings in Denmark, used for offices, businesses, stock and public administration, amount to ∼
7.2 million m 2 and work carried out in these office environments contributes to more than half of
the Danish gross domestic product. Notably, the cost of poor IEQ in Danish office buildings adds
an additional ∼ 30 billion DKK per aunnum. However, despite these facts, IEQ improvements
are often neglected in favour of other potential energy and cost savings.
The lack of current IEQ measurements and available data are two of the many reasons leading
to its neglect. As a result, poor IEQ is often referred to as an invisible danger. This master thesis
aims to make IEQ visible, measurable, and understandable to occupants and building owners.
The motivation behind this lies in the myriad possibilities to provide building owners with tools to
understand and improve IEQ in their office buildings. As such, the following work aims to use the
’Internet of Things’ (IoT) to investigate IEQ and its implications, as well as to explore means by
which decision-makers can come to view IEQ improvements more favourably.
In this thesis, the IEQ of three separate offices was investigated, using both measurements with
three IoT devices (out of five total examined devices) and occupant questionnaires. Of the
examined IoT devices, this study concluded that the uHoo and RoomAlyzer were superior for
IEQ office measurements because of their ease of use and range of measurable parameters.
Moreover, through the use of a benchmarking tool, developed alongside industry stakeholders,
the following work highlights the positive correlation between good IEQ and occupant productivity.
Throughout the development of this benchmarking tool, building owners and decisionmakers
were interviewed on multiple occasions, ensuring alignment between their needs and
the abilities of the benchmarking tool.
The project resulted in a completed benchmarking tool, consisting of weighted IEQ parameters,
a grading scheme, economic estimations, and a unique IEQ report. Given the common
neglect of IEQ in office buildings, the study concluded that the benchmarking tool’s greatest
value was its ability to allow building owners to grade the IEQ in their offices and predict economic
gains should the IEQ be improved. The project laid a foundation for future benchmarking
databases, allowing stakeholders to benchmark the IEQ in their offices while simultaneously
sharing their knowledge, experiences, and expertise.

Resumé
Dårligt indeklima kan forårsage helbredsproblemer, allergier, ubehag, lav koncentrationsevne,
træthed osv. I kontormiljøer kan dårligt indeklima og dets relaterede symptomer resultere i både
nedsat produktivitet og nedsat arbejdsevne. De økonomiske omkostninger i kontorer forårsaget
af dårligt indeklima er blandt andet medicinske behandlinger, sygefravær og nedsat produktivitet.
Bygninger der anvendes til kontorer, virksomheder, lager og offentlig administration i Danmark
udgør op mod ∼ 7.2 millioner m 2 . Arbejde udført i disse kontormiljøer bidrager til mere end
halvdelen af det danske bruttonationalprodukt, og omkostningerne ved dårligt indeklima i kontorbygninger
i Danmark nærmer sig årligt ∼ 30 milliarder DKK. Alligevel, nedprioriteres indeklimaet
ofte til fordel for potentielle energi- og omkostningsbesparelser.
En af grundene til, at indeklimaet nedprioriteres, er, at det sjældent måles, og at dets påvirkning
derfor er ukendt. Dårligt indeklima omtales derfor ofte som en usynlig fare. Dette speciale har
til formål at gøre indeklimaet synligt, målbart og forståeligt for både brugere og bygningsejere.
Motivationen bag dette ligger i mulighederne for at give bygningsejere værktøjer til at forstå og
forbedre indeklimaet i deres kontorbygninger. Derfor vil projektet undersøge brugen af ”Internet
of Things” (IoT) til at synliggøre indeklimaet og dets konsekvenser og endvidere, hvad der skal til
for at beslutningstagerne prioriterer indeklimaet i deres kontorer.
Indeklimaet blev derfor målt i tre separate kontorer ved hjælp af både spørgeskemaer og
målinger med tre forskellige IoT-sensorer (ud af fem undersøgt). Enhederne uHoo og RoomAlyzer
blev, på baggrund af en sammenligning af fem enheder, med henblik på brugervenlighed
og antal målbare parametre, anbefalet til indeklimamålinger i kontorer.
Med benchmarkingværktøjet, der blev udviklet med involvering af relevante aktører, fremhæver
projektet yderligere sammenhængen mellem godt indeklima og høj medarbejderproduktivitet.
I forbindelse med udviklingen af dette benchmarkingværktøj blev bygningsejere og beslutningstagere
fra kontorerne interviewet ved flere lejligheder for at sikre, at det udviklede benchmarkingværktøj
mødte deres behov og mangler.
Projektet resulterede i et værktøj bestående af en vægtning af indeklimaparametrene, en vurderingsordning,
økonomiske estimeringer og en indeklima-rapport. Med henblik på den observerede
nedprioritering af indeklimaet på kontorer, blev det i projektet vurderet, at det vigtigste
ved benchmarkingværktøjet var bygningsejernes mulighed for indeklimavurdering, samt
beregningerne af de økonomiske gevinster et forbedret indeklima kan medføre. Projektet udgør
et grundlag for en fremtidig benchmarkingdatabase, hvor aktører kan benchmarke deres kontors
indeklima og dele viden samt erfaringer.

Table of
Contents

Preface
Abstract
Resumé
iii
v
vii
1 Introduction 2
1.1 Project Context . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
1.2 Project Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
2 Indoor Environment 8
2.1 Legislative Authorities and Guidelines for IEQ in Offices . . . . . . . . . . . . . . . . . . . 10
2.2 Sick Building Syndrome (SBS) Symptoms and IEQ Parameters . . . . . . . . . . . . . . . 10
2.3 IAQ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
2.4 Thermal Comfort . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
2.5 Acoustic Comfort . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
2.6 Visual Comfort . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
2.7 Summary of Parameters and Symptoms . . . . . . . . . . . . . . . . . . . . . . . . . . 18
2.8 Smart Technologies, Digitalisation and IoT . . . . . . . . . . . . . . . . . . . . . . . . . 19
3 Market Research 24
3.1 Benchmarking and Certification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
3.2 IoT Devices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
4 Method 36
4.1 IEQ Investigation and Analysis Process . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
4.2 Measurement Devices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
4.3 Offices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
4.4 Questionnaires . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
4.5 Data Processing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
4.6 Benchmarking Process . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
4.7 Stakeholder Matrix . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52
4.8 Interviews and Value Proposition Canvas . . . . . . . . . . . . . . . . . . . . . . . . . . 53
4.9 Economic Estimations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
5 Results 58
5.1 Preliminary Device Evaluation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
5.2 IEQ Investigation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67
5.3 Stakeholders and Value . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72
5.4 Benchmarking Tool . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74
5.5 IEQ report . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78
6 Discussion 86
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6.1 IEQ Investigation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88
6.2 Benchmarking tool . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89
6.3 Future implications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91
7 Conclusion 94
7.1 Fulfilment of objectives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96
7.2 Fulfilment of overall purposes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97
Appendix A Desk Study Sensors 110
Appendix B Questionnaire 111
Appendix C Stakeholder matrix 117
Appendix D Interview guide 118
Appendix E Interview #1 119
Appendix F Interview #2 122
Appendix G IEQ Investigation 124
Appendix H Parameter Weighing 125
Appendix I Economic calculations 126
Appendix J IEQ Reports 129
INDOOR ENVIRONMENT IN A DIGITAL FUTURE
xi

Abbreviations and
Nomenclature
BREEAM
CASBEE
DGNB
DTU
GB
GDPR
GDP
HQE
IAQ
IEQ
IoT
LBC
LEED
NAAQS
NABERS
PIR
PM
RH
SBi
SBS
SPL
TVOC
VOC
VPC
WELL
Building Research Establishment Environmental Assessment Method
Comprehensive Assessment System for Building Environmental Efficiency
German Sustainable Building Council
Technical University of Denmark
Green Building
General Data Protection Regulation
Gross Domestic Product
High Environmental Quality
Indoor Air Quality
Indoor Environmental Quality
Internet of Things
Living Building Challenge
Leadership in Energy and Environmental Design
American National Ambient Air Quality Standard
National Australian Built Environment Rating System
Passive InfraRed
Particulate Matter
Relative Humidity
Danish Building Research Institute
Sick Building Syndrome
Sound Pressure Level
Total Volatile Organic Compound
Volatile Organic Compound
Value Proposition Canvas
German Sustainable Building Council

List of Tables
2.1 CO2 criteria and guidelines [16][29] [31] . . . . . . . . . . . . . . . . . . . . . . 13
2.2 WHO guidelines for particulate matters [34] . . . . . . . . . . . . . . . . . . . . 13
2.3 TVOC guidelines from the German Federal Environmental Agency [37] . . . . . . 14
2.4 Limit values for air pollution and guidelines [38] [31] . . . . . . . . . . . . . . . . 14
2.5 Design criteria for temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
2.6 Design criteria for humidity in occupied spaces . . . . . . . . . . . . . . . . . . 15
2.7 Continuous sound levels from background noise [15] . . . . . . . . . . . . . . . 16
2.8 Lighting in offices [15][49] . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
2.9 Overview of IEQ guidelines and related symptoms . . . . . . . . . . . . . . . . . 18
3.1 Certification and benchmarking tools . . . . . . . . . . . . . . . . . . . . . . . 29
3.2 Occurrence of parameters within the four IEQ categories . . . . . . . . . . . . . 32
3.3 Average accuracy for investigated devices with known accuracy . . . . . . . . 33
3.4 Market research on IoT devices . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
4.1 Results from checklist . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
4.2 Temperature Calculations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
4.3 CO2 Calculations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
5.1 Key numbers from the 24h measurements . . . . . . . . . . . . . . . . . . . . . 61
5.2 Grading distribution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75
5.3 Potential productivity increase . . . . . . . . . . . . . . . . . . . . . . . . . . . 77

List of Figures
1.1 Building phases and examples of challenges within these [6] [7]. . . . . . . . . . . . . 4
1.2 Stakeholders in the building industry. . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
2.1 SBS-symptoms [21]. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
2.2 IEQ categories and parameters [22] [15] . . . . . . . . . . . . . . . . . . . . . . . . . 11
2.3 Average percentages of the weighting of IEQ categories [24] . . . . . . . . . . . . . . 12
2.4 Temperature and colour scale [52] . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
2.5 Elements of smart cities and intelligent buildings . . . . . . . . . . . . . . . . . . . . . 19
2.6 Architectural layers in IoT systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
2.7 Example of payload from IoT device . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
2.8 Limitations and possibilities for IoT devices . . . . . . . . . . . . . . . . . . . . . . . . 21
3.1 Process of the benchmarking desk study . . . . . . . . . . . . . . . . . . . . . . . . . 28
3.2 Methods and Grading Schemes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
3.3 GB credit distribution and IEQ parameter occurrence in percentages [76] . . . . . . . 32
4.1 IEQ Investigation and analysis process . . . . . . . . . . . . . . . . . . . . . . . . . . 38
4.2 Devices and parameter coverage . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
4.3 RoomAlyzer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
4.4 uHoo . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
4.5 Foobot . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
4.6 Sens’it . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
4.7 IC-meter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
4.8 Office #1 Expan . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
4.9 Office #2 Frisesdahl . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
4.10 Office #3 Frisesdahl . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
4.11 Floor plan office #1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
4.12 Floor plan office #3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
4.13 Office #3 Frisesdahl . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
4.14 Structure and topics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
4.15 Example of a question from the questionnaire in English . . . . . . . . . . . . . . . . . 49
4.16 Data processing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
4.17 Benchmarking investigation and development. . . . . . . . . . . . . . . . . . . . . . 51
4.18 Stakeholder ’Power/Interest’-matrix [107]. . . . . . . . . . . . . . . . . . . . . . . . . 52
4.19 Value Proposition Canvas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
5.1 Evaluation of device and dashboard usability . . . . . . . . . . . . . . . . . . . . . . 60
5.2 24h CO2 measurements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62
5.3 24h CO2 box plot . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62
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5.4 24h TVOC measurements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63
5.5 24h TVOC box plot . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63
5.6 24h temperature measurements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64
5.7 24h temperature box plot . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64
5.8 24h humidity measurements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65
5.9 24h humidity box plot . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65
5.10 24h noise measurements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66
5.11 24h noise box plot . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66
5.12 CO2 results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67
5.13 TVOC results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68
5.14 PM2.5 results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69
5.15 Temperature results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69
5.16 Humidity results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70
5.17 Noise results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71
5.18 Stakeholder ’Power/Interest’-matrix . . . . . . . . . . . . . . . . . . . . . . . . . . . 72
5.19 Value Proposition Canvas based on interviews . . . . . . . . . . . . . . . . . . . . . . 73
5.20 IEQ weighting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74
5.21 Radar for office #2 and #3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75
5.22 Radar office #1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76
5.23 Potential cost saving savings for office #1 . . . . . . . . . . . . . . . . . . . . . . . . . 78
5.24 IEQ Report development process . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79
5.25 Feedback session #1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79
5.26 Feedback session #2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79
5.27 Grading scheme results for office #1 . . . . . . . . . . . . . . . . . . . . . . . . . . . 80
5.28 Office #1’s grading scheme results for the four IEQ categories . . . . . . . . . . . . . . 81
5.29 Grading results for IEQ categories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81
5.30 CO2 measurements for office #1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82
5.31 Symptoms related to CO2 for office #1 . . . . . . . . . . . . . . . . . . . . . . . . . . 82
5.32 Complaint related to CO2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83
INDOOR ENVIRONMENT IN A DIGITAL FUTURE
xvii

CHAPTER 1
Introduction
Chapter 1 introduces the project background in a national
and international perspective. It provides an overview of the
project context including the challenges within different building
phases and the stakeholders in the industry. Furthermore, it
presents the digital aspects of the future building industry and
indoor environment on a national and institutional level. In the
light of the indoor environment quality challenges, stakeholders
and the digital possibilities, chapter 1 presents the project
description and approach.

Today many countries, including Denmark, rely on a large number of people working in offices. Currently,
an average of 36% of the European workforce, or 81.4 million people, work in an office environment
[1]. In Denmark, work carried out in office environments contributes to more than half of
the Danish gross domestic product (GPD) [2].
The large number of people working in offices is due to a significant economic shift, moving away
from the manufacturing sector and towards the knowledge-based and service sector. Consequently,
understanding the indoor environment quality (IEQ) in offices has never been more important [3].
Poor IEQ can lead to a wide range of health issues including allergies and asthma. Every year, the
economic costs of treatments, medical care, loss of work and low productivity related to dampness
and mould reach €82 billion across Europe [4]. Moreover, research conducted at the Technical
University of Denmark shows that poor IEQ in office buildings results in significant economic losses
due to lowered productivity. And the cost of poor IEQ in old office buildings in Denmark adds up to
∼30 billion DKK [2].
1.1 Project Context
Buildings used for offices, businesses, stock and public administration in Denmark amount to ∼7.2
million m 2 [5]. Most of these buildings face different challenges within the different building phases.
Challenges related to IEQ are mainly experienced in the operation and renovation phase as illustrated
in Figure 1.1.
Figure 1.1: Building phases and examples of challenges within these [6] [7].
Renovation has a great possibility of prolonging the operational phase of a building. However, in the
renovation phase of a building, the IEQ and occupants’ well-being is often neglected in favour of potential
energy savings and minimised costs [8]. As a result, a major challenge within the operational
4 INDOOR ENVIRONMENT IN A DIGITAL FUTURE

phase of an office building is poor IEQ, which affects occupants’ well-being and productivity. Improvements
hereof could potentially lead to great economic benefits. In the UK, studies have shown
that a good office environment could increase the productivity with up to 20%, which is equivalent
to £135 billion per year. In the US, research showed a national economic yield up to $12-125 billion
per year [3].
To help favour improved IEQ and occupants’ well-being in renovations, a greater understanding of
the various building industry stakeholders is necessary [9]. The stakeholders involved in, or affected
by, the IEQ in the operational phase of an office building and before renovation are presented in
Figure 1.2.
Figure 1.2: Stakeholders in the building industry.
In an office perspective, the main stakeholders are the tenant (a company e.g.), the occupants (the
employees of the company), and the administration which is the intermediary between the tenant(s)
and the owner of the building. To avoid neglecting IEQ and occupants’ well-being, stakeholders and
decision-makers should have easy access to knowledge and experiences from the building industry
regarding IEQ [9].
Digitalisation has great potential to create this needed transparency in the building industry. It could
encourage an increased focus on common goals and collaboration within the industry. Using data
from digital devices, the construction and operation phase of a building can become more efficient
and innovative ideas and new solutions could be prioritised [6].
Research on the use of IT shows that Denmark is one of the most digitalised countries in Europe.
Despite this, the level of digitalisation in the Danish building is below the European average [10]. On
the 30th of January 2019, the Danish Ministry of Transport and Housing took action towards changing
the low degree of digitalisation in the Danish building industry, by launching a digital strategy with
18 initiatives focusing on better use of digital tools, open formats, common standards, better use of
data, digital competencies for the entire value chain and more sustainable construction through
digitalisation [6].
On an institutional level, DTU Civil Engineering has, as a part of the university’s strategy for 2025,
designated exactly the digitalisation of construction as one of three strategic focus areas for the
INDOOR ENVIRONMENT IN A DIGITAL FUTURE 5

coming five years. The strategy encourages research on digitalisation of buildings, focus on future
digital aspects of the built environment, and an increased use of Internet of Things (IoT), sensors, big
data, data-driven modelling and building diagnostics [11].
1.2 Project Description
It is often said that poor IEQ is an invisible danger. Warm temperatures, high CO2-levels, noise, chemicals
in the indoor air etc. cannot be seen with the human eye. However, several of these IEQ parameters
can cause severe dissatisfaction and discomfort amongst occupants. This master thesis
project aims to make these parameters and IEQ issues visible, measurable and understandable to
occupants and building owners. The motivation in this work lies in the possibilities to provide buildings
owners with tools to understand and improve IEQ in their office buildings. With this project, we aspire
to get a deeper understanding of IEQ related issues in offices and to challenge status quo of IEQ
investigation by exploring new technologies. The intention hereof is to gain knowledge on indoor
environment in a digital future.
The master thesis is a part of the PhD study ’Benchmarking the indoor environment in office buildings
- characterization, synthesis, and practical application’. The purpose of the study is to characterise
IEQ, occupants’ well-being, health, and productivity in office buildings located in both Denmark
and Greenland. Furthermore, it aims to build up a comprehensive database containing occupant
and building information, which will be continuously expanded. In addition to this, the database will
provide the core of a new benchmarking tool offering building owners to evaluate the performance
of their building and workplace [12].
With this master thesis project we aim to contribute with an investigation and evaluation of state-ofthe-art
digital measurement devices to possibly be used in the PhD study. Furthermore, the intention
is to provide insights on relevant stakeholders and their motivation and concerns towards IEQ
databases and benchmarking tools. Lastly, we aim to present a benchmarking tool which could
potentially be used in the PhD study.
The methods used in this master thesis consist of two parts. One part focuses on the measurement
devices and IEQ analysis. Another part focuses on stakeholders and the development of a benchmarking
tool including an IEQ report. The two parts intertwine and both parts of the project are
based on a literature review and market research followed by analysis.
Objectives
1. Characterisation and comparison of existing benchmarking tools related to IEQ and available
technologies within IEQ measurement devices
2. Collection and analysis of IEQ data from office buildings
3. Identification of relevant stakeholders and the challenges related to IEQ they face
4. Development of a benchmarking tool and a detailed IEQ report
5. Evaluation and optimisation of the benchmarking tool and the IEQ report through feedback
sessions with the identified stakeholders
6 INDOOR ENVIRONMENT IN A DIGITAL FUTURE

CHAPTER 2
Indoor
Environment
Chapter 2 presents an overview of the authorities, legislation,
requirements and guidelines relevant to indoor environment
quality (IEQ) in Danish office buildings. Furthermore, it presents
a review of existing literature and previous studies on indoor
environment, sick building syndrome (SBS) and the parameters
affecting it. In addition, chapter 2 describes smart technologies,
digitalisation and the concept ’Internet of Things’ (IoT)
which in this case refers to sensor devices connected to the
internet.

2.1 Legislative Authorities and Guidelines for IEQ in Offices
The Building Regulations specify the requirements of the Danish Building Act and contain the detailed
requirements that all construction work must comply with [13]. The building regulations ensure that a
building is designed and built to satisfy fire, safety, health and energy requirements. Violation of the
building regulations can result in fines.
The Danish Standards are common and repeated application documents providing guidelines. They
are developed and evaluated in collaboration with the Ministry of Industry [14]. One of the key
standards, used in this project, with regards to indoor environment is DS/EN 16798 [15].
DS/EN 16798 evaluates the quality of a building on a four scale stated to IEQ, where I is the highest
level and IIII is lowest. However, the most common levels are II and III, as level I is mainly used for
buildings with elderly or sick occupants. Level II represents a regular level, and is used for design
and operation and therefore as reference in this project. Level III and IIII are mainly used to describe
the IEQ in existing buildings and thus occupants in buildings within these categories may experience
dissatisfaction [15][16].
The Danish Working Environment Authority supervises companies and provides guidance on the
working environment. It is the Danish Authority who must ensure a safe, healthy and inspiring work environment,
as well as prevention of attrition, sickness absence and exclusion from the labour market.
The Danish Working Environment Authority distinguishes between documents of a legal and informative
nature and provide guidance and information towards both [17]. One of the key guidance
regarding indoor environment, used in this project, is A. 1.2-1 [18]
2.2 Sick Building Syndrome (SBS) Symptoms and IEQ Parameters
The term presenteeism describes occupants who are present at their workplace, but working with
a reduced performance [19]. Presenteeism can be caused by both psychological discomfort and
physical discomfort [20]. This project focuses on the physical discomfort related to poor IEQ and
SBS-symptoms which are presented in Figure 2.1. Symptoms related to SBS can be divided into four
categories: general symptoms, mucous membrane, skin, and respiratory symptoms [21].
Figure 2.1: SBS-symptoms [21].
10 INDOOR ENVIRONMENT IN A DIGITAL FUTURE

SBS-symptoms are generally short-term effective which means that occupants will experience symptoms
shortly after being exposed to pollutants or a dissatisfying indoor environment. This can result in
long-term health issues. Anyhow, the focus of this project is the short-term effects leading to presenteeism
or sickness absence [20]. The presenteeism or sickness absence caused by SBS-symptoms are
primarily affected by parameters within the IEQ categories indoor air quality (IAQ), thermal comfort,
visual comfort and acoustic comfort [20]. The parameters within these categories are presented in
Figure 2.2.
Figure 2.2: IEQ categories and parameters [22] [15]
Several studies concerning IEQ satisfaction with the IEQ in conventional and green buildings 1 have
shown that it is highly unlikely for occupants to have full satisfaction with IAQ, visual, acoustic, and
thermal comfort parameters simultaneously [20]. In fact, multiple studies have found that there is a
gap in research on the relative impact of the IEQ categories in conventional office buildings. Therefore,
it is not clear which category has the largest effect on occupants’ (dis)satisfaction and health,
and, there is no existing ranking system of the categories or parameters within conventional buildings
[24]. However, research conducted looking at the ranking of the different IEQ categories’ effect on
occupancy (dis)satisfaction within green buildings.
The study presented in Figure 2.3 compared the ranking of IEQ categories relative to each other
from a number of different research papers. Figure 2.3 shows that IAQ caused the most dissatisfac-
1 Buildings that reduces/eliminates negative impacts on the climate and natural environment in the design, construction
and operational phase [23].
INDOOR ENVIRONMENT IN A DIGITAL FUTURE 11

tion among occupants. Followed by thermal and acoustic comfort. The research suggested that
the dissatisfaction within these two categories could be due to the fact that thermal and acoustic
comfort is difficult for individuals to control in open-space offices. The category ranked as having the
lowest impact was visual comfort. Nonetheless, it should be emphasised that studies have demonstrated
that sufficient lighting conditions have a positive impact on productivity and, that insufficient
light moreover has the potential for major dissatisfaction [24].
Figure 2.3: Average percentages of the weighting of IEQ categories [24]
2.3 IAQ
Good IAQ refers to indoor air without harmful concentrations of contaminants and with a great majority
of occupants being satisfied [25]. Studies have shown that indoor air can be more than 5 times
as polluted as outdoor air. Poor IAQ is globally acknowledged as a significant health, environmental
and economic problem [26] [27]. It has been found that higher satisfaction with the IAQ in office
buildings leads to higher work productivity and lower stress levels [26]. Furthermore, previous studies
have discovered a decrease in productivity of 6-9 % in poor IAQ environments, compared to
environments with acceptable IAQ [25]. The most common contaminants are inorganic gases, particulate
matter (PM) and volatile organic compounds (VOC) [25]. IAQ recommendations are often
measured as limit values/concentrations, hourly/yearly means or a combination of both. It is often
measured in ppb, ppm, or μm/m 3 .
Carbon Dioxide
Occupants respiration is the primary source of CO2 in an office and, thus, it can be used to indicate
whether the ventilation rate supplied to an office is adequate. A high CO2-concentration can
cause SBS symptoms, such as headache, fatigue, eye irritation, nasal and respiratory symptoms [28].
The maximum CO2-level recommended from both the Danish Working Authority and the Danish
Standard Association are presented in Table 2.1. These recommendations are equal to a maximum
indoor CO2-level of 600-800 ppm above the outdoor air’s CO2-level which is approximately 400 ppm
[29]. Furthermore, the Danish Building Research Institute (SBi) has provided guidelines for CO2-levels
in indoor air [30]. The criteria and guidelines are presented in Table 2.1.
12 INDOOR ENVIRONMENT IN A DIGITAL FUTURE

Maximum level
Danish Working Environment Authority
Danish Standard Association
SBi’s guidelines
Good IEQ
Less Good IEQ
Poor IEQ
1000 ppm
1200 ppm
<800 ppm
800-1000 ppm
>1000 ppm
Table 2.1: CO2 criteria and guidelines [16][29] [31]
Particulate Matter
PM is a mixture of solid and/or liquid particles suspended in air. They can vary in size, shape and
composition, and they can change because of temperature and humidity. Indoor sources of particles
include occupants, their activities, heating, chemical reactions, tobacco smoke, printers etc.
However, particles from the outside air can also contaminate the indoor air. PM10 is usually known
as dust and has a diameter of approximately 10 µm. PM2.5 is defined as fine particles and has a
diameter below 2.5 µm. Both particles can be inhaled. However PM2.5 is considered to be more
harmful than PM10, as the smaller particles can be inhaled deeper into the lungs and absorbed into
the bloodstream [32]. Studies have linked PM exposure to SBS-symptoms such as eye irritation, nose
and throat irritation, headache, skin irritation, fatigue and lack of concentration [33]. Denmark does
not yet have any limit values for particulate matters, but The Danish Working Authority recommends
compliance with WHO guidelines presented in Table 2.2.
Annual mean 24 hours mean
PM 2.5 10μg/m 3 25μg/m 3
PM 10 20μg/m 3 50μg/m 3
Table 2.2: WHO guidelines for particulate matters [34]
Volatile Organic Compounds
VOCs are organic compounds, common in indoor environments. The indoor level of VOCs is typically
significantly higher than the outdoor level. VOCs originate from building materials, cleaning supplies,
interior furnishing, occupants, food as well as processes, such as cleaning, printing and cooking [35].
High concentrations of VOCs have been associated with SBS-symptoms, such as throat and nose
irritation, eye irritation, headaches and fatigue [36].
When measuring and eliminating VOCs, TVOC is a common term. TVOC is the total concentration
of multiple VOCs simultaneously present in the air. It is cheaper to measure TVOC compared to individual
VOCs. As Denmark does not have guidelines for TVOC, the German guidelines are presented
in Table 2.3.
INDOOR ENVIRONMENT IN A DIGITAL FUTURE 13

Exposure Limit TVOC [ppb]
1 Excellent no limit 0-65
2 Good no limit 65-220
3 Moderate < 12 months 220-660
4 Poor < 1 month 660-2200
5 Unhealthy hours 2200-5500
Table 2.3: TVOC guidelines from the German Federal Environmental Agency [37]
Other Inorganic Gases
Some of the most common nonindustrial indoor air pollutants amongst inorganic gasses are nitrogen
dioxide (NO2), ozone (O3) and carbon monoxide (CO). There are no specific danish regulations for
these pollutants in office environments, but the Danish Working Authority provides a list of limit values
for air pollution in general. These are presented in Table 2.4. Furthermore, SBi has provided guidelines
for a number of indoor air pollutants including NO2, O3 and CO. The guidelines indicate the effect
that the pollutant might have on the occupant under different levels of the pollutant. These are also
presented in Table 2.4. The American National Ambient Air Quality Standard (NAAQS) also provides
average daily (8 hours working day) limit values for the pollutants in indoor air. However, experts
recommend to maintain levels at 50% or less than the NAAQS [33].
Exposure to O3 can result in shortness of breath, throat and nose irritation for both healthy occupants
and even more so for individuals with preexisting airways diseases ie. asthma. The main sources of
O3 in offices are from outdoor air and air purifiers.
CO exposure can cause fatigue, headache and shortness of breath and even death in severe cases
with high exposures. The main sources of CO in offices are from gas appliances and environmental
tobacco smoke. However, the severity of CO poisoning is dependent on the concentration, time of
exposure, and the general health status of the exposed occupant.
Exposure to NO2 can lead to shortness of breath, coughing and wheezing. The main sources of NO2
in offices are from gas/heating appliances and roadside fumes from outdoor air.
Ozon Carbon Monoxide Nitrogen dioxide
Limit values for air pollution
Danish Working Authority 100 ppb 20 ppm 500 ppb
National Ambient Air Quality Standard 80 ppb 9 ppm 53 ppb
Sbi guidelines
Low/no effect <30 ppb <0.5 ppm <80 ppb
Medium effect 30-50 ppb 0.5-9 ppm 30-300 ppb
High effect >50 ppb >9 ppm >300 ppb
Table 2.4: Limit values for air pollution and guidelines [38] [31]
14 INDOOR ENVIRONMENT IN A DIGITAL FUTURE

2.4 Thermal Comfort
Thermal comfort is mainly influenced by temperature and humidity, as well as personal factors such
as clothing and activity level [39]. Thermal discomfort can have a negative effect on mood, productivity,
and performance. Due to differences in personal preferences, it is usually difficult to achieve
thermal satisfaction for all occupants in a building at all times [25].
Temperature
Previous studies discovered a link between temperature and productivity in office buildings. While
there is no significant improvement or deterioration in productivity between 21-24 °C, increasing the
temperature up to 21 °C is associated with statistical improvement in productivity. In contrast, an
increase above 24 °C is associated with significant decrease in productivity [40][41]. In addition to
this, Seppänen (2003) showed productivity amongst occupants had a linear decrease of 2% per
increased °C in temperature above 25 °C [42]. Furthermore, high temperatures can cause nose irritation,
rashes, eye irritation, headaches, fatigue and lack of concentration [43] [44] [45]. The Danish
Standard Association guidelines from DS/EN 16798 for temperature ranges for both heating and cooling
seasons are presented in 2.5. These are the recommended temperature ranges in both single
and landscaped offices.
Heating season 20-24 °C
The Danish Standard Association
Cooling season 23-26 °C
The Danish Working Environment Authority Offices 20-22 °C
Table 2.5: Design criteria for temperature
As seen in Table 2.5, the Danish Working Environment Authority recommends a smaller temperature
range for office buildings, as temperatures above 23 °C cause an increased amount of complaints
from occupants. In addition to this, the Danish Working Environment Authority advises that the indoor
temperature does not exceed 25 °C in a room with sedentary work [18].
Relative Humidity
When the relative humidity is high, the natural evaporation from the body, which has a cooling effect,
is reduced. Relative humidity above 70% can therefore lead to discomfort. Relative humidity below
20% on the other hand, can cause eyes, nose, throat and skin irritation [43]. In addition, a high level
of humidity is less acceptable than a low level of humidity [46]. However, the humidity has minimal
impact on the thermal comfort at temperatures above 26 °C [47]. Table 2.6 presents the danish
standard (DS16798) recommendations for when to dehumidify and humidify in an office [15].
Dehumidification 60%
Humidification 25%
Table 2.6: Design criteria for humidity in occupied spaces
INDOOR ENVIRONMENT IN A DIGITAL FUTURE 15

2.5 Acoustic Comfort
Acoustic comfort is often understood as an acceptable level of noise. However, the perception of
sound is more complex, and often it depends not only on the sound level, but also on factors such
as reverberation time, sound insulation and absorption. In an office building, acoustic comfort is the
capacity to protect occupants from indoor and outdoor noise and provide a good acoustic working
environment [39].
Noise
Noise is defined as unwanted sound [19]. An office can have two noise sources: external and internal.
External sources include noise from outside, such as traffic, machinery and the public. Internal
sources include noise from within the office, such as co-workers conversations, machine sounds, telephones
and office equipment.
Noise and poor acoustics can lead to a decrease in productivity, stress, fatigue, headache and
lack of concentration [43]. Studies have shown that occupants exposed to continuous external
noise, such as traffic noise, have higher levels of blood pressure and stress hormones. One study
showed a 66% decreased in performance within memory tasks when the occupants were exposed
to different types of background noises [19]. The Danish Standard Association’s recommendations
for continuous sounds levels from sounds generated by building service systems, also referred to as
background noise, are presented in Table 2.7. The Danish Working Environment Authority recommends
that sound-levels do not exceed 70 dB in a furnished office room.
Small office ≤ 35
Landscape office ≤ 40
Conference room ≤ 40
Table 2.7: Continuous sound levels from background noise [15]
2.6 Visual Comfort
Visual comfort in offices includes daylight, illuminance, glare and colour temperature. Studies have
shown daylight to have as a positive effect on health and glare as one of the most reported complaints
[39]. To enable occupants to perform visual tasks efficiently and accurately, appropriate
lighting at work spaces is essential. Appropriate light levels are achieved by both natural and/or
artificial light [25] [48].
The Danish Working Environment Authority states, that in addition with sufficient lighting from daylight
and artificial lighting, the outdoor surroundings should be visible [48]. Regarding the intensity
of artificial lighting, a study concerning the association of sick building syndrome with indoor air parameters
showed that the light intensity was significantly correlated to symptoms such as skin dryness,
eye irritation and fatigue [43].
16 INDOOR ENVIRONMENT IN A DIGITAL FUTURE

Single office
Landscaped office
Meeting rooms
Surroundings
500 lux
500 lux
500 lux
300 lux
Table 2.8: Lighting in offices [15][49]
Table 2.8 presents the lighting criteria for work spaces in landscaped and single offices, as well as
meeting rooms according to DS12464 and DS16798. This should be obtained from a combination
of both daylight and artificial lighting [49]. The surrounding area, which is defined as more than 0.5
m from the area of the task, should meet the requirements of 300 lux [50]. Despite the fact that
there are no guidelines for maximum lightning in neither the Danish Standard nor the Danish Building
Regulations, excessive lighting may also result in discomfort. There is some evidence of increased
discomfort at illuminance above 1000 lux [51]. Furthermore, reflections and glare can cause fatigue
and headaches [48].
Correlated Colour Temperature
Artificial lighting can have either a red tint referred to as a warm colour temperature, a blue tint,
referred to as a cold colour temperature, or neutral indicating a white tint. Incandescent lamps
usually have warm colour temperatures, while fluorescent lamps and LEDs typically have cold colour
temperatures. The colour temperatures are indicated in Kelvin (K) as presented in Figure 2.4. In offices,
a neutral colour temperature of 3000-4000 K is often preferred [52].
Figure 2.4: Temperature and colour scale [52]
INDOOR ENVIRONMENT IN A DIGITAL FUTURE 17

2.7 Summary of Parameters and Symptoms
Table 2.9 presents an overview of the IEQ categories, their parameters, guidelines and related symptoms.
The guidelines which are based on literature, research, standards and regulation previously
presented are divided into the categories good, acceptable and unacceptable. The other air pollutants
than the specified include Ozone, NO and CO which have different limits and the guidelines
are therefore not included in the Table. As seen on the Table several of the parameters can cause
the same symptoms, hence experienced symptoms related to one parameter could also be caused
by another parameter. Furthermore, some of the parameter might be related to other symptoms or
symptoms not listed simply because it has not been investigated or scientifically proven. This Table
however, gives a reasonable overview of guidelines and symptoms and has been used as a reference
through the rest of this project.
CO2
ppm
Indoor air quality
PM2.5
μm/m 3
VOC
ppb
Other
pollutants
Temperature
°C
Guidelines
Thermal comfort
RH
%
Acoustic
comfort
Noise
dB
Visual
comfort
Good 0-800 0-10 0-220 20-23 25-60 <40 >500
Acceptable 800-1200 10-25 220-660 18-20 and 23-25 20-25 and 60-70 40-70
Unacceptable >1200 >25 >660 <18 and >25 <20 and >70 >70 <500
Fatique
x
Lack of concentration
Headache
x
Shortness
of breath
Cough
x
Wheeze
x
Throat
irritation
Eye
irritation
Nose
irritation
Dryness
of skin
Skin
irritation
Rash
x
SBS symptoms
General symptoms Respiratory symptoms Mucous membrane symptoms Skin symptoms
Light
Lux
Table 2.9: Overview of IEQ guidelines and related symptoms
18 INDOOR ENVIRONMENT IN A DIGITAL FUTURE

2.8 Smart Technologies, Digitalisation and IoT
Building audits and investigations of IEQ and related symptoms have been conducted using measurement
devices for several decades. Despite this, collected data, results and experiences have
not been shared to the detriment of fellow stakeholders. This is referred to as ’knowledge silos’. The
cross-sectoral silos which include producers, knowledge institutions, citizens, municipalities etc. are
often separated from each other and, thus, the knowledge of one does not benefit the others. However,
smart technologies, digitalisation and IoT have expanded the possibilities for data collection,
analysis and knowledge sharing [9].
Societies, cities or buildings which use IoT and/or undergo technological transformations are often
referred to ’smart cities’ or ’intelligent buildings’. Smart cities and intelligent buildings are composed
of a physical, digital and communicative elements as presented in Figure 2.5 [9].
Figure 2.5: Elements of smart cities and intelligent buildings
The digital element, which in this project is IoT devices, can be used to investigate and document
the physical context, (in this project office buildings). The strength of IoT devices, dashboards and
databases lie in their ability to collect, store, provide and share data about their surroundings. The
communicative element can be used to both communicate and visualise the results of investigations
and documentation in order to improve the physical context. The communicative element in this
project is focused on visualisations of technical data targeting relevant stakeholders [9].
All three elements are important when trying to breach the knowledge silos in order to enable stakeholders
to, not only share experiences, but also to recognise their shared interests and inspire one
another to find and develop smarter solutions [9].
Denmark has the potential of utilising the possibilities of all three elements because of its digital maturity
and high level of digitalisation. In fact, Danish citizens are some of the most frequent users of
the internet and smart phones in the entire EU. Furthermore, Denmark is ranked as the fourth most
developed country in the world when it comes to e-governance opportunities. Moreover, there is a
great potential towards open source and sharing of data in Denmark [9].
INDOOR ENVIRONMENT IN A DIGITAL FUTURE 19

In order to fully comprehend the possibilities and limitations of IoT, it is crucial to understand the different
elements in IoT systems. The term ’Internet of Things’ was first introduced in 1999, and described
as a system where sensors acted like the eyes and ears of a computer: an entirely new way for computers
to see, hear and interpret their surroundings [53]. Figure 2.6 presents the architectural layers
of IoT systems. The context of the IoT system can be buildings, infrastructure and factories etc.
Figure 2.6: Architectural layers in IoT systems
The ’T’ in IoT are devices with one or more sensors, including thermometers measuring the temperature,
gas detectors measuring pollution, passive infrared sensors registering occupancy etc. The IoT
devices are in the”edge” of the network. There are more than 50 billion IoT devices worldwide [54].
The data from sensors, are called payloads and to make sense of the payload it must be stored and
analysed. An example of such is presented in Figure 2.7.
Figure 2.7: Example of payload from IoT device
The transportation and storage of payloads is the ’I’ in IoT. The data is transported through network
connections like the well-known Wi-Fi or Bluetooth or other protocols such as LoRa, NB-IoT or Sigfox
[54]. The payload of the device is most commonly sent to local servers called nodes. There are
millions of nodes categorised as ”Fog”. The nodes are transient storage for immediate data and
performs real-time analytics or analytics performed on data while it is being collected. The goal
of the ”Fog” is to improve the efficiency of local and cloud data storage, sorting and minimising
the amount of data required to be sent to the cloud to advance data analysis efficiency and the
security of IoT [54]. The ”Cloud” is a term used to describe data centres. It stores data summaries
from multiple fog nodes and performs deeper analysis on large data sets [54].
20 INDOOR ENVIRONMENT IN A DIGITAL FUTURE

Figure 2.8 presents a number of limitations and possibilities of using commercial IoT devices to measure
IEQ in office buildings. Amongst the limitations is the fact that some of the commercial IoT devices
have a lower quality than the highly accurate measurement devices typically used in research
facilities. An example of this is a study conducted at DTU which investigated the dependency of air
temperature on the CO2-concentration accuracy for commercial low-cost CO2 sensors. The experiment
was conducted under different temperatures and CO2-concentrations where highly accurate
instruments were used for reference temperatures and CO2-concentrations. The study showed that
one of the two investigated devices was positively temperature dependent [55].
For longer periods of measuring the battery life time may also be a limitation. Often the frequency
of the payloads send to the dashboards determines the battery life. A battery for a device might
have a life time of months if the device sends a payload once every hour but will only last for days if it
sends a payload every minute [56]. Furthermore, the efficiency of the IoT devices is also dependent
on a reliable internet connection whether it is Wi-Fi, Bluetooth, LoRa, NB-IoT or Sigfox [54].
Additionally, it is important to keep in mind that even though IoT devices are often referred to as smart
objects, they are only as smart as the developers of the devices, their algorithms and dashboards.
This means that knowledge on IEQ parameters, symptoms related to poor IEQ and regulations on IEQ
must not be underestimated.
Likewise, the occupants and their perceptions should not be neglected in favour of solely using IoT
devices for investigation of IEQ. However, IoT devices could help visualise and document IEQ to back
up occupant perception or assist in finding the source of dissatisfaction. Some IEQ parameters which
cause symptoms might be impossible for occupants to detect but IoT data can help making these
invisible risks visible.
Some other great possibilities when using IoT devices to measure the IEQ is the connection to the
cloud which allows for storage of great amounts of data for analysis as well as data sharing between
stakeholders. Furthermore, the IoT architecture allows for real-time analysis and automation which
can help address IEQ issues as they occur [54].
Documentation of IEQ, investigation and visualisation of risks, cloud solutions for databases, IEQ analysis
and automation are important factors in a benchmarking perspective, which is one of the primary
elements in this project.
Figure 2.8: Limitations and possibilities for IoT devices
INDOOR ENVIRONMENT IN A DIGITAL FUTURE 21

CHAPTER 3
Market Research
Chapter 3 presents a market research on benchmarking tools
and green building certifications. The motivation behind benchmarking
is described along with the findings from the market
research. This includes the application, stakeholders, methods,
grading schemes and parameters. Furthermore, chapter
3 presents the market research on IoT devices. It gives an
overview of the investigated devices along with price and accuracy
intervals.

3.1 Benchmarking and Certification
In order to improve and understand the IEQ in office buildings, building stakeholders need to be
aware of the building’s performance and potential improvements. Here, green building certifications
and benchmarking tools can be useful, but they are often quite extensive. The tools can be used to
rate and compare buildings, and thereby inform the stakeholders about the IEQ and advise about
potential improvements.
A wide range of benchmarking tools and green building certifications related to IEQ in buildings
already exist globally. In Denmark the most implemented green building certification is DGNB managed
by the Danish Green Building Council. DGNB is a complete evaluation of the building and
mostly addressing new buildings or buildings after an extensive renovation with a focus on their sustainability
level [57]. As DGNB mostly focuses on sustainability, the certification process can be too
complicated for existing buildings, when trying to improve their IEQ. Therefore, a comprehensive
database including a benchmarking tool can make it easier for existing buildings to evaluate their
indoor environment and estimate potential gains of improving the IEQ without undergoing an extensive
certification process.
To obtain more knowledge about existing benchmarking tools and certifications worldwide, a desk
study was performed. The desk study aimed to investigate their method, the parameters used to
evaluate and analyse buildings, especially the IEQ parameters, and in addition to this, how they
visualise their results. The investigated tools and certifications have different purposes, but with sustainability
and IEQ as recurring themes. Some of them mainly focus on rating the level of sustainability
for a building and some are aiming to improve living and working conditions in the buildings.
Figure 3.1: Process of the benchmarking desk study
The 21 investigated certification and benchmarking tools are presented in Table 3.1, which gives an
overview of methods, IEQ parameters, and grading schemes, before further explanation.
28 INDOOR ENVIRONMENT IN A DIGITAL FUTURE

Origin Method IEQ Rating
Sustainbility
BBB Bæredygtig
Boværdi Barometer [58]
Denmark Questionnaire Radar
DGNB [59][60][61] Germany Third-party Medals
LEED [62] USA Third-party Medals
BREEAM [63][61] UK Third-party Stars
FRAME[64]
Denmark
Register and
planning tool
RET
Nordic Swan Ecolabel [65][61] Denmark
Third-party and
LCA
Label
Miljöbyggnad [61] Sweden Third-party Medals
Totalværdimodellen [66] Denmark Web-based Radar
HQE [67][61] France Third-party Stars
Green Star[61] Australia Third-party Stars
Green Globes [68] USA Third-party Globes
LBC [69][61] USA Measurements Label
CASBEE [61] Japan Third-party
Letters and
stars
Building performance
Minergie [61] Switzerland Third-party
Letters and
label
Berkeley benchmarking tool [70] USA Web-based Numbers
NABERS Indoor
Environment Tool [71]
Australia Third-party Stars
Rebus
IQ-Compass [72][73]
Denmark Calculation tool Letters
Mobistyle [74] Netherland Measurements Nudging
Active House [61]
Denmark
Calculation
Radar and
tool
label
TAIL [75] Denmark RET
Colour and
roman letters
WELL v2 [61] USA Third-party Medals
IAQ Thermal Visual Acoustic
Table 3.1: Certification and benchmarking tools
INDOOR ENVIRONMENT IN A DIGITAL FUTURE 29

Application and Stakeholders
In the desk study, different purposes and target groups were discovered. Some of the investigated
tools are primarily used before applying for certification. They can be helpful when preparing for
the certification process, and during the design and planning process, which means they generally
involve developers, engineers, architects and consultants. FRAME and Berkeley are tools within this
category. FRAME helps to manage and document sustainability in projects, before applying for a
DGNB certification. Berkeley’s occupant survey and benchmarking tool can be useful in preparation
for a certification such as LEED, since it analyses the success of the design, and provides a database
for comparing similar buildings, so stakeholders can act on their results by applying modifications.
Some tools are simply labels or marks, raising awareness of the building type and met requirements.
The target group for these tools are mostly building owners, tenants and administration. Nordic Swan,
LBC and Active House are tools within this category. Most of the tools, however, provide the developer,
buildings owners or administration referred to as the applicants, with a level of certification.
These tools have a larger target group, as the level of certification can be attractive for everyone involved
from the designing to the operation phase. Other than the application process, the methods
for granting a certification is different for the investigated tools and certifications.
Methods
As seen in Table 3.1, the different benchmarking and certification tools use different methods to analyse
and rate a building. The most consistent methods are referred to as web-based, measurements,
questionnaire and third-party. The method distribution is illustrated in Figure 3.2. As the only one
BBB (Bæredygtig Boværdi Barometer), is entirely based on a questionnaire. A few are solely based
on measurements. For example, American LBC, which has a 12-months performance-recording period,
and Dutch Mobistyle, which aims to motivate behavioural change by installing small interactive
screens in offices. Others are web-based such as the American Berkeley and the Danish Totalværdimodellen,
where the results are outcomes of an online survey or web-tool. The greater part of the
tools uses an online registration and documentation platform, and they have verification by a thirdparty
assessor, who verifies the uploaded performance. Regardless of their methods, all the tools
illustrate their results with some kind of visualisation and the applicants can obtain different levels of
certification to indicate how well the building complied with the requirements.
Grading Schemes
All the investigated tools use different grading schemes, and often with 4-6 different levels. The highest
levels are often extremely hard to achieve. Three grading schemes recur: stars, medals and letters
as illustrated in Figure 3.2, the distribution of tools using a specific grading scheme is explored. The
most popular grading scheme is stars, which is used by tools such as Australian NABERS, French HQE
and British BREEAM. While American LEED, WELL and German DGNB use medals where the applicant
can achieve Gold, Silver, Bronze and Platinum. Furthermore, Swiss Minergie, Danish IQ-Compass and
Japanese CASBEE present their results with letters. In addition to this, some tools use numbers, colours,
globes and radars to visualise their results, and a few use a mix of two grading schemes. Moreover,
some of the investigated tools are entirely labels, achieved if a building complies with the tools or
certifications requirements. Certifications within this category are Nordic Swan, Active House and
LBC. These labels are well known in society since many everyday products and materials have different
labels, showing if they meet the requirements within a specific area such as allergy, chemicals,
30 INDOOR ENVIRONMENT IN A DIGITAL FUTURE

testing and sustainability. Nordic Swan operates with labels for both products and buildings and is
well known in Scandinavia. LBC is a strict sustainability label with two versions of marks: living and
petal. Other than a label or grading scheme, most of the certifications and tools provide a detailed
report about the results, and the rating is based on a deeper analysis with a wide range of parameters.
Investigating the IEQ parameters is interesting for this project in order to obtain knowledge
about which to include in a benchmarking tool and database.
Figure 3.2: Methods and Grading Schemes
Parameters
A previous study has explored Green Building certificates’ distribution of credits assigned to each of
the four IEQ categories [76]. A focus in this desk study was on the occurrence of the parameters
within the four categories: IAQ, thermal, visual and acoustic comfort. This was done by counting the
tools and certifications different IEQ parameters related to each of the four categories.
INDOOR ENVIRONMENT IN A DIGITAL FUTURE 31

IAQ Thermal comfort Acoustic comfort Visual comfort
Parameters 10 5 2 4
Occurrence 42 out of 107 25 out of 107 16 out of 107 24 out of 107
Table 3.2: Occurrence of parameters within the four IEQ categories
Table 3.2 illustrates the number of different parameters within each of the four IEQ categories. Furthermore,
it illustrates the occurrence of the parameters within the categories. Some of the tools,
do not identify which specific parameters they apply within a category, but only that it includes the
category. An example of parameters identified which were related to IAQ were ventilation, CO2,
pollution, particles, mould, VOC and CO. The distribution of credits in Green Building (GB) certification’s
schemes [76] and the occurrence of parameters within the four IEQ categories in the desk
study are presented in Figure 3.3.
Figure 3.3: GB credit distribution and IEQ parameter occurrence in percentages [76]
Figure 3.3 indicates a connection between GB credits assigned to different IEQ categories and occurrence
of parameters within different IEQ categories in the desk study. IAQ is the category with
most assigned GB credits and with the highest occurrence of parameters in the desk study. This
could indicate that IAQ is considered as having a major importance compared to the other categories
but also that the category is simply composed of more measurable or significant parameters.
The dedication of credits and occurrence of parameters in the IAQ category comply with findings
of the research previously described in this project, which found IAQ to be the category causing
the most dissatisfaction amongst occupants compared to other IEQ parameters. The category with
the second most GB credits and occurrence of parameters is thermal comfort category followed
by the visual and acoustic comfort category. It is important to mention that the investigated tools
and certification do not necessarily measure the applied parameters, but they incorporate them in
their analysis. Lastly, it must be acknowledged that some IEQ categories or parameters have low
representation or are simply not included in the GB schemes and benchmarking tools even though
they are relevant for characterising the IEQ of the building. The reasons hereof could be measuring
difficulties or lack of research and references defining the acceptable levels [76].
32 INDOOR ENVIRONMENT IN A DIGITAL FUTURE

3.2 IoT Devices
A market research on available IoT devices with sensors played a major role in the investigation of
which devices to use for the measurement of IEQ in this project. The market research was conducted
as a desk study using primarily information from the respective producers of the devices and information
from the literature review. The aim of the desk study was to discover IoT devices which measured
multiple IEQ parameters within different price ranges. Furthermore, the purpose of the desk study was
to get an overview of the level of accuracy of the devices.
The desk study included 21 IoT devices. All of the investigated sensors measured temperature and
relative humidity and two thirds of the devices measured CO2 as well. The devices measured on
average 5 of the 9 relevant parameters which were described in section 2.2 ”Requirements for IEQ in
Danish office buildings”. The price range of the devices was 522-4306 DKK and the average cost of
the investigated devices was ∼1500 DKK. Furthermore, several of the IoT devices had a dashboard
service with a monthly or yearly subscription cost.
Table 3.3 shows an overview of the number of devices which measured the given parameters, along
with the number of devices where it was possible to obtain the accuracy for the parameter. Furthermore,
the table presents the average and median accuracy for the devices with known values.
Investigated
devices
Devices with
known accuracy
Average
accuracy
CO2 PM2.5 TVOC Gasses
Temperaturpancy
Occu-
RH Noise Light
14 11 11 1 21 21 5 4 2
8 4 4 1 14 14 0 0 0
± 55ppm ± 10 µg/m 3 ± 10 ppb ± 0.4 ◦ C ± 2%
Table 3.3: Average accuracy for investigated devices with known accuracy
Three intervals were defined in order to compare the accuracy of the various sensors in the devices.
The three intervals were defined as best, medium and worst third of the difference between the
lowest and highest accuracy for each parameter. The calculation of the three intervals for accuracy
of the temperature sensors in the devices is shown below as an example. This method has been used
to calculate the intervals for all devices with known values.
Lowest value = Min v = ± 0.1 ◦ C
Highest value = Max v = ± 1 ◦ C
Interval size = Int s = Max v - Min v = ± 1 ◦ C - ± 0.1 ◦ C = ± 0.9 ◦ C
Unknown value =
Interval 1 [ ± ◦ C ] = = [ Min v ; Min v + Int s ] = [ 0.1 ; 0.1 + 0.3 ] = [ 0.1 ; 0.4 ]
Interval 2 [ ± ◦ C ] = = ] Min v + Int s ; Min v + Int s·2 ] = ] 0.1 + 0.3 ; 0.1 + 0.3 ·2 ] = ] 0.4 ; 0.7 ]
Interval 3 [ ± ◦ C ] = = ] Min v + Int s ·2 ; Min v + Int s·3 ] = ] 0.1 + 0.3 ·2; 0.1 + 0.3 ·3 ] = ] 0.7 ; 1.0 ]
The same method was used to divide the devices into three intervals related to the purchase price
of the devices. Interval one defines cheaper devices, interval two defines medium priced devices
and interval three higher priced devices.
INDOOR ENVIRONMENT IN A DIGITAL FUTURE 33

Unknown value =
Interval 1 [DKK] = = [ Min v ; Min v + Int s ] = [522 ; 522 +1261 ] = [522 ; 1783 ]
Interval 2 [DKK] = = ] Min v + Int s ; Min v + Int s·2 ] = ] 522 +1261 ; 522 +1261·2 ] = ]1783 ; 3045]
Interval 3 [DKK] = = ] Min v + Int s ·2 ; Min v + Int s·3 ] = ] 522 +1261·2; 522 +1261·3 ] = ]3045; 4306]
The complete list of investigated devices is presented in Figure 3.4 with intervals indicated by colours
and in appendix A with exact prices and accuracy. The overview indicates that higher prices devices
are rare and that accuracy for noise, light, TVOC and particles are difficult to obtain. Moreover it
indicates that high and medium priced devices guarantee a higher accuracy.
Total number
of paramters
Roomalyzer [40] 7
Price
CO2
RH Noise Light TVOC PM2.5
Other
pollutants
Temperature
Occupancy
TheO [77] 6
uHoo [78] 6
Awair [79] 5
Awair omn [80] 5
Huma-i [81] 5
Foobot [82] 5
Air mentor [83] 5
Sens’it [84] 4
Temptop [85] 4
Netatmo [86] 4
Laser Egg [87] 4
Wave Plus [88] 4
Air Visual [89] 4
IC-Meter [90] 4
RYSTA [91] 4
Iclever [92] 3
Eve room [93] 3
Hummbox [94] 3
INSAFE+ [95] 3
SIGLINK [96] 2
Table 3.4: Market research on IoT devices
Another aspect of the desk study investigated the source of power and the network connection.
The majority of devices in the desk study were powered by batteries. A few of the devices should be
plugged-in to a power source and some had both possibilities. Regarding the network connectivity
the majority of the devices needed an external Wi-Fi connection and one third of the devices could
use a sim card implemented in the device.
The overview and additional information obtained in the desk study were used later when deciding
which devices to investigate further, and which to use for measurements in the project.
34 INDOOR ENVIRONMENT IN A DIGITAL FUTURE

CHAPTER 4
Method
Chapter 4 describes the methods used in this project. The chapter
consists of two parts. The first part presents the methods
used for the IEQ Investigation and analysis process. This includes
the description of measurement devices, the offices
used for measurements, the applied questionnaire and data
processing. The second part presents the methods used in
the benchmarking process. This part includes a description of
the stakeholder analysis, interview method, a value proposition
canvas and a presentation of the economic estimations
which were used as a part of the developed benchmarking
tool.

4.1 IEQ Investigation and Analysis Process
The IEQ investigation and analysis in this project consisted of four steps, as presented in Figure 4.1 The
first step, market research on IoT devices, was presented in the previous chapter and devised a list of
devices of which five were chosen. These selected devices spanned a broad range of prices and
accuracy levels, such that a wide variety of devices was investigated.
The second step consisted of a preliminary device evaluation aiming to investigate usability and
differences in test measurements. This allowed for an improved understanding of the five devices as
well as a comparison of device usability and performance.
Subsequently, in the third step, the devices were used to collect data in three separate offices. This
was done concurrently with questionnaires administered to office occupants in order to obtain both
objective and subjective data regarding IEQ.
The last step consisted of analysis of the measurements from the offices and the occupant questionnaires.
The results of these analysis were used later in the project for visualisation and benchmarking
purposes, with a focus on the possible economic gains of improving the IEQ in the offices. The final
step consisted of an analysis of the data from the measurements and questionnaires. These results
were later used for visualisation and benchmarking purposes, with a focus on possible economic
gains from office IEQ improvement.
Figure 4.1: IEQ Investigation and analysis process
38 INDOOR ENVIRONMENT IN A DIGITAL FUTURE

4.2 Measurement Devices
When choosing devices for this project, the different IEQ categories were taken into consideration,
and, a selection of devices collectively covering parameters within each category was prioritised.
Furthermore, the selection represents a variety of devices produced for experimental, residential
and commercial use. As presented in Figure 4.2, most parameters were measured with multiple of
the devices, allowing for the possibility of comparing the devices.
Figure 4.2: Devices and parameter coverage
INDOOR ENVIRONMENT IN A DIGITAL FUTURE 39

RoomAlyzer
The RoomAlyzer is produced by the Danish company, IoT Fabrikken. In comparison with other devices
from the market research, this device is medium-priced (1795 DKK + monthly subscription of 29-69
DKK) and has high accuracy within all parameters with known values (listed below). It is primarily for
commercial use and has operational conditions of 0-50 ◦ C and 0-95% RH and can cover rooms of
100m 2 or greater in cases with high air circulation. However, if the device is used for estimating the
occupancy based on detection of movement, it must be within 12 meters of its target(s), since the
range of the PIR-sensor is 12 m [97] [56].
List of parameters:
• CO2 (± 45 ppm)
• TVOC (± 15% of measured value)
• Temperature (± 0.2 ◦ C)
• Relative humidity (± 2%)
• Light and Light colour
• Movement
• Noise
Figure 4.3: RoomAlyzer
The RoomAlyzer uses two C batteries. It is placed vertically on the wall with an adhesive hook in
the height of occupants’ heads (1.2-1.5 m above the floor). The device should be placed out of
direct sunlight and preferably in the direction of the entrance to the room. The device is turned
on with a magnet and starts measuring when the blue LED on the device is blinking. The device is
calibrated from the production and has automatic calibration while in use. The device measures
every 15 minutes and transmits data through NB-IoT to the RoomAlyzer dashboard once every hour
when the room is occupied and once every fourth hour when the room is not occupied [56].
Data which is collected, stored and processed through the device and dashboard is owned solely by
the customer. RoomAlyzer may perform statistical analysis on anonymised aggregated data from
multiple customers [56], yet, data handling complies with the requirements of the General Data
Protection Regulation (GDPR) and can be deleted by the customer at all times.
40 INDOOR ENVIRONMENT IN A DIGITAL FUTURE

uHoo
The uHoo is produced by a Hong Kong-based company specialising in indoor air quality. In comparison
with other devices from the market research, this device is medium-priced (2230 DKK + a
yearly subscription of 2040 DKK) and has a medium accuracy within all parameters with known values
(listed below). It is the largest device used within this project. It is primarily for residential use and
its operational conditions are 0-40 ◦ C and 5-95% RH (non-condensing). It is recommended to use
one device per 50-80 m 2 for high-precision measurements, however one device can cover up to
80-120 m 2 , although with lower precision [98] [78].
List of parameters:
• CO2 (± 50 ppm or 3%)
• PM2.5 (± 5 µg/m 3 and 15% reading)
• TVOC (± 10 ppb and 5% reading)
• Carbon monoxide (± 10 ppm)
• Ozone (± 10 ppb or 5% reading)
• Nitrogen dioxide (± 10 ppb or 5% reading)
• Relative humidity (± 3%)
• Temperature (± 0.5 ◦ C)
Figure 4.4: uHoo
The uHoo should be placed on a desk or at occupant breathing height (usually 1-1.5 m above the
floor). The device should be placed out of direct sunlight and at minimum 1 m away from doors or
windows. Furthermore, the device should not be placed close to copy machines, microwaves etc.
The device must be plugged into a power source and connected to WiFi for setup. The calibration
time is 48 hours. The device transmits data through WiFi. The data can be obtained on a minute-basis
or hourly average from the uHoo dashboard.
The collection, storage and processing of data from the device, app and dashboard complies with
the requirements of the GDPR and personal information is thus not shared without the user’s consent.
However, the user can authorise uHoo to share current and historical air quality measurements and
data with third parties. Personal information is deleted when the service is no longer needed or
upon request. uHoo may share anonymised information on air quality measurements for industry
and market analysis, geographic profiling, marketing, advertising and other business purposes [78].
INDOOR ENVIRONMENT IN A DIGITAL FUTURE 41

Foobot
The Foobot is produced by the Luxembourgish company Airboxlab. In comparison with other devices
from the market research, this device is low-priced (1300 DKK) and has a low accuracy within all
parameters with known values (listed below). It is the heaviest device used in this project. It is primarily
for residential use and its operational conditions are 15-45 ◦ C and 30-85% RH. The device can cover
70-140 m 2 [82][99] [100]. List of parameters:
• Temperature (± 1 ◦ C)
• Relative humidity (± 5%)
• PM2.5 (± 5 µg/m 3 and 15% reading)
• TVOC (± 15% of measured value)
Figure 4.5: Foobot
The Foobot should be placed on a desk or at occupant breathing height (usually 1-1.5 m above
the floor). The device must be plugged in a power source and connected to WiFi for setup. When
setting up the device, it must remain at maximum 2 m away from a WiFi router. The initial calibration
time is six days. If the device is turned off after the initial calibration, it requires a calibration of three
hours. The device transmits data through WiFi allowing data to be obtained on a minute-basis from
the Foobot dashboard [99].
Data from the device, app and dashboard is collected, processed, and stored through third-party
service providers and complies with the requirements of the GDPR. Personal information is deleted
after five years or upon request. Foobot however may share or sell anonymised data publicly and
to third parties without customer consent or compensation. The anonymised data will be retained
indefinitely for purposes of data analysis but cannot be directly linked to any specific user [82].
42 INDOOR ENVIRONMENT IN A DIGITAL FUTURE

Sense’it
The Sense’it device is produced by the French global network operator company, Sigfox. In comparison
with other devices from the market research, this device is low-priced (522 DKK + yearly
subscription of 140 DKK) and has a medium accuracy within all parameters with known values (listed
below). It is the smallest and lightest device used in this project. The device is primarily produced for
experimentation and demonstration of the possibilities in the realm of IoT devices. There is therefore
no developed user guide or coverage specification. Its operational conditions are -10-50 ◦ C and
10-90% RH. It measures the below listed parameters [101] [102].
List of parameters:
• Temperature (± 0.5 ◦ C)
• Relative humidity (± 3.5%)
• Light
• Door opening detection (± 0.244, 0.488, 0.976 mg and ± 0.1 μT/LSB)
• Vibration detection (± 0.244, 0.488, 0.976 mg and ± 0.1 μT/LSB)
• Magnet detection
Figure 4.6: Sens’it
The device can be plugged into a power source or can use the built-in battery with a lifetime of
3 weeks to 3 months depending on the measurement rate. The device can be placed on a table
or desk, or vertically on a wall with velcro. The device can measure using one sensor at a time. It
has an LED display with one button that can be used to turn the device on/off or select the desired
sensor for measurements. The device can measure every 10 minutes, every hour or on occurrence
and transmits the data through Sigfox to the Sens’it dashboard [102].
Collected data from the device and dashboard is processed and stored through third-party service
providers and complies with the requirements of the GDPR or corresponding requirements in non-
European countries. Personal information is only retained for as long as services are provided and is
deleted upon request [84].
INDOOR ENVIRONMENT IN A DIGITAL FUTURE 43

IC-Meter
The IC-meter GSM 4.2 is produced by the Scandinavian company, IC-meter. In comparison with
other devices from the market research, this device is high-priced (4306 DKK) and has a high accuracy
within all parameters with known values (listed below). It is primarily for commercial use and its
operational conditions are -20-80 ◦ C and 0-95% RH. It is recommended to use one IC-meter for each
room, however, several devices can be used if the purpose of the measurements is to investigate
differences in the IEQ within a larger room such as an open space office. It measures the below listed
parameters [90] [103].
List of parameters:
• CO2 (± 30 ppm + 3% reading)
• Temperature (± 0.3 ◦ C)
• Relative humidity (± 2)
• Noise
• Activity level
Figure 4.7: IC-meter
The IC-meter must be plugged in a power source when measuring. The IC-meter is placed vertically
on an inner wall or in an IC-meter stand close to the wall to ensure the most correct noise measurement,
since measurements in the middle of the room can result in readings up to 6 dB(A) lower than
the actual level. The correct placement is 1.2 m above the floor and out of direct sunlight. The distance
to heaters and seats must be at least 1.5 m. The device measures every 5 minutes and can
transmit the data through WiFi or LoRa to the IC-Meter Dashboard [103].
Data which is collected, stored and processed through the device and dashboard is owned solely
by the customer. The data handling complies with the requirements of the GDPR. IC-Meter provides
the customer with the possibility to share parts of the data with selected parties or to publish it. Data
collected with a device is encrypted before it is sent to the IC-Meter Cloud [90].
44 INDOOR ENVIRONMENT IN A DIGITAL FUTURE

4.3 Offices
Using a checklist developed by DTU for the purpose of investigating IEQ in buildings, more knowledge
was obtained regarding each office. These results are presented in Table 4.1.
Office # 1 Office # 2 Office # 3
Construction Year 2015 2002 2008
Last Renovated - 2009/2010 -
Office Area 100 m2 70 m2 120 m2
Occupants 7 6 8
Occupancy 07:30-16:30 06:45-16:30 06:30-17:15
Floor Ground First First
Connecting Rooms
Hallway
Printer room, toilet
and kitchenette
Entrance, storage,
and meeting room
Tenancy/Owner Owner Owner Owner
Heating/Cooling
Radiator and
air condition
Radiator and
air condition
Floor heating and
air condition
Facade East/West South/East East/South/West
Shading Elements Internal Internal Interval
Windows Three layer Double Double
Cleaning Everyday Wednesday & Sunday Wednesday & Sunday
Table 4.1: Results from checklist
Figure 4.8: Office #1 Expan Figure 4.9: Office #2 Frisesdahl Figure 4.10: Office #3 Frisesdahl
INDOOR ENVIRONMENT IN A DIGITAL FUTURE 45

Office #1
The first investigated office belongs to EXPAN, a producer of concrete components for buildings [104].
The office is located in one of EXPAN’s buildings in Brørup and is mainly used for producing technical
drawings. It was accommodating 7 out of 8 possible occupants at the time of the investigation.
Figure 4.11: Floor plan office #1
The office was divided into two zones as seen in Figure 4.11 with four workstations in each zone. The
devices were placed near each of the end walls at 1.2 m above the floor. IC-Meter and uHoo were
placed near the end wall facing north, and RoomAlyzer was placed near the end wall facing south
in the direction of the entrance.
Despite successful measurements in the preliminary evaluation of the devices, problems with the
device, uHoo, appeared in this office. While installing the sensors at EXPAN’s office, it became apparent
that the company has a captive portal network which requires log-in through a dedicated
web-page. As such, the IT department needed to add uHoo’s MAC address to their positive list.
However, the IT department was not successful and uHoo could therefore not be used for the investigation
in office #1 [98]. The zones were therefore represented solely by IC-Meter and RoomAlyzer.
Furthermore, Figure 4.11 illustrates the sun’s path around the building, which may have an impact on
the IEQ. The red crosses illustrate the position of the devices.
46 INDOOR ENVIRONMENT IN A DIGITAL FUTURE

Floor plan office #2
The second and third offices both belong to the contracting company, Frisesdahl A/S [105]. Office
#2 is located in one of Frisesdahl’s buildings in Askov and accommodates 6 occupants. The office is
an older office, where mainly secretary work is done.
Figure 4.12: Floor plan office #3
The office was divided into three zones with two workstations in each zone, as shown in Figure 4.12.
The devices were placed on the dividing wall between the open-space office and the remaining
rooms at height of around 1.2 m. In this case, uHoo was placed in zone 1 close to the copy room as it
is the device measuring the most IAQ parameters. Conversely, IC-Meter was placed in zone 2, as it is
the device measuring the least number of parameters. RoomAlyzer was placed in zone 3, because
this zone is connected with the kitchen, and RoomAlyzer is the device measuring the second largest
amount of parameters.
Furthermore, Figure 4.12 illustrates the sun’s path around the building, which may have an impact on
the perceived IEQ. The red crosses illustrate the position of the devices.
INDOOR ENVIRONMENT IN A DIGITAL FUTURE 47

Office #3
The third investigated office is also located in Frisesdahl A/S’s building in Askov. At the moment, it
accommodates 6 out of 8 possible occupants. Office #3 is a newer office building consisting of
project managers.
Figure 4.13: Office #3 Frisesdahl
The office was divided into three zones with three workstations in both zone 1 and 2, and two workstations
in the last zone, as demonstrated in Figure 4.13. The devices were placed on shelves on the
walls in the east and west directions, as well as on the wall in the north direction. All devices were
placed approximately 1.2 m above the floor. In this case, uHoo was placed in zone 3 close to the
printer/copier and coffee machine because it is the device measuring the most IAQ parameters.
IC-Meter and RoomAlyzer were placed in zones 1 and 2, respectively.
Furthermore, Figure 4.13 illustrates the sun’s path around the building, which may have an impact on
the perceived IEQ. The red crosses illustrate the position of the devices.
48 INDOOR ENVIRONMENT IN A DIGITAL FUTURE

4.4 Questionnaires
The occupant questionnaire used for this project is a modification of a standardised questionnaire
developed at DTU for the purpose of investigating occupant perception of IEQ in office buildings.
Here, questionnaires were distributed via e-mail to all occupants in the three offices. The use of onlinedistributed
questionnaires poses the risks of a lack of process control and a decreased response rate.
However, the online survey method was chosen for this project because it allows for the use of visual
aids and eliminates the interview effect in which respondents are influenced by the interviewer’s
appearance, gesture, method of interviewing and other behaviours. Furthermore, the online survey
method minimises the effect of geographical distance and is both cost- and time-efficient [51] [106].
The questionnaire was provided in Danish in consideration of the respondents’ native language. A
time limit of ten minutes was set in order to minimise the burden of the survey and obtain as many
completed questionnaires as possible. Prior to answering questions, respondents were informed that
the survey is anonymous and that their answers will not be linked to their identity. Furthermore, respondent
answers were handled in accordance with the GDPR. The structure of the questionnaire
and the topics of the questions are presented in Figure 4.14. The initial part of the questionnaire
covers background information on the occupant’s office. This is followed by questions regarding
the occupant’s perception of, and satisfaction with, individual IEQ parameters. Finally, the respondent
is asked to rate various building functions and his/her overall perception of the IEQ in the office
building.
Figure 4.14: Structure and topics
The questionnaire consists primarily of factual and perceptual questions, both of which allowed for
questions to be answered within a scale or a closed category. The scale intentionally has six options,
leaving out a neutral answer option and thereby forcing the respondents to commit themselves to
either the lower or higher end of the rating scale. The categories for estimation of the regularity of
dissatisfaction or symptoms is presented in the example in Figure 4.15. The entire questionnaire is
presented in appendix B.
Figure 4.15: Example of a question from the questionnaire in English
INDOOR ENVIRONMENT IN A DIGITAL FUTURE 49

4.5 Data Processing
In order to analyse the data from the measurements and the questionnaires, the data was processed
as presented in Figure 4.16. Here, the data from the measurement devices were downloaded from
the dashboards in xlsx or csv files and processed in Microsoft Excel. Similarly, the data from the questionnaires
were copied from a data presentation link and pasted in Excel where it was processed as
well. The data from the measurement devices were visually displayed in graphs and box plots for
comparison analysis. This was filtered such that only data from occupied hours were included. The
results hereof were analysed alongside an evaluation of questionnaire data for IEQ complaints and
symptoms in order to evaluate the IEQ in the three offices. The combined data presentation of questionnaire
and IEQ data were in the form of accumulated bar charts which included the percentage
of occupied hours within the IEQ categories good, acceptable and unacceptable along with the
percentage of occupant complaints and symptoms.
Figure 4.16: Data processing
50 INDOOR ENVIRONMENT IN A DIGITAL FUTURE

4.6 Benchmarking Process
The benchmarking investigation and development performed in this project consisted of four steps,
which are presented in Figure 4.17. The first step was the market research on benchmarking tools
and Green Building certificates, which was presented in the previous chapter. The insights from the
market research were used as inspiration later in the project.
The second step in the benchmarking process consisted of a stakeholder matrix analysis. This method
was in order to get an overview of stakeholder roles in a renovation or IEQ improvement process.
Based on the stakeholder matrix, a number of building owners were interviewed in order to investigate
the possible value of a benchmarking tool for IEQ of their building, this was done through a
value proposition canvas.
The third step was the development of a grading scheme for IEQ. This step was based on the interviews
with the relevant stakeholders, the value proposition canvas and the market research of
benchmarking tools. Furthermore, this step included economic estimations on the possible gain
from improving the IEQ in the offices.
The last step in the benchmarking process concerned communication of the results of the IEQ analysis,
final grading and the economic estimations. In order to do so a number of visualisations were
prepared. The the value proposition canvas was used as framework for the visualisations. The visualisations
were presented for the previously interviewed stakeholders and feedback sessions were
conducted.
Figure 4.17: Benchmarking investigation and development.
INDOOR ENVIRONMENT IN A DIGITAL FUTURE 51

4.7 Stakeholder Matrix
The stakeholder matrix analysis was used to investigate the interest and power of the stakeholders in
office buildings in different owner/tenant constellations. This was done in order to get an overview of
stakeholder roles in a renovation/IEQ improvement process. The four quadrants of the power-interest
grid, presented in Figure 4.18, can be seen as defining four categories of stakeholders with high and
low power and interest in a project, situation or job [107].
The most important and influential stakeholders who can support a job or process are the ’players’.
The ’subjects’, while interested, have less influence. However, coalition could increase their power
and convert them into ’players’. The ‘context setters’ can influence the future overall context for a job
or process. They are typically perceived as having the same values as the organisation who is driving
the job or process, but lacking awareness and motivation to support it. Ways of increasing their
interest and encouraging them to support the objectives of the organisation should be considered.
The ’crowd’ can be seen as potential rather than actual stakeholder. However, their interest and/or
power could be raised to convert them into ’subjects’ or ’context setters’ [107].
Figure 4.18: Stakeholder ’Power/Interest’-matrix [107].
This stakeholder matrix method was developed for cases in which a company owns and is the main
user of an office building as well as for cases in which a company rents an office building through
an administration firm. The matrix was, in part, formulated on the basis of a meeting with the administration
company Newsec [108].
52 INDOOR ENVIRONMENT IN A DIGITAL FUTURE

4.8 Interviews and Value Proposition Canvas
A number of building owners were interviewed based on the stakeholder matrix for the case in which
a company is the owner and user of the building. This was done in order to investigate the owners’
motivation behind a possible or actual renovation of their building. Furthermore, the interviews investigated
the possible value of an IEQ-benchmarking tool for the building owners. The interviews were
conducted as semi-structured conversations with questions. Before the interviews, the structure and
questions were specified in an interview-guide which is presented in appendix D. After the interviews
were transcribed and coded, an analysis in the form of a value proposition canvas (VPC) was made.
The VPC is a structured method to examine the value of a product or service from the customer or
user’s perspective. As seen in Figure 4.19, the canvas consists of the customer profile (right) and
the value map (left). Each segment consists of three sections focusing on specific features of the
customer or user and product or service, respectively [109].
The customer profile on the right includes the customer or users’ job(s). In the context of this project,
the customer is the building owner and a plausible job could therefore be to ”improve the IEQ in
the office”. It also includes pains, which are the problems they might face in completing their tasks.
Furthermore, it includes gains, which are the positive outcomes that the customer expects from completing
the job. The value map to the left represents the product or service and how it can help the
customer complete their job. It includes pain relievers, which is how the product or service can minimise
or reduce the customers pains. Moreover, it includes the gain creators, which are meant to
improve the customer experience. While the customer or user may have many jobs to be completed,
the value proposition canvas can help to focus in on one job or situation. The more matches
between value map and customer profile, the higher chances that the product or service will be
useful [109].
Figure 4.19: Value Proposition Canvas
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4.9 Economic Estimations
The estimations of the possible economic gain of improving the IEQ and hereby heightening the
occupant productivity are, in this project, based on a modified version of the methods used in the
previous project Totalværdi Indeklima. The project Totalværdi Indeklima (2017) [110] developed
a tool with the purpose of estimating possible productivity improvements in a IEQ context. The tool
includes the parameters temperature and CO2-level and is designed to be a simple and easy to
handle tool for different stakeholders. Despite light and noise also being considered important, current
knowledge about linking these parameters to productivity is insufficient, and they are thus not
included in the calculation tool [110].
The calculation for temperature impact on productivity is based on the study ’Effect of Temperature
on Task Performance in Office Environment’ by Seppänen et al. (2006) [111]. In light of this study, an
equation describing productivity linked with temperature, was formulated as presented in Equation
4.1. The equation was used to modify the calculation sheet from ”Totalværdi og Indeklima”, such that
the calculations were based on the temperature categories: good, acceptable and unacceptable
defined in this project [112][113].
P = 0.1647524 · T – 0.0058274 · T 2 + 0.0000623 · T 3 – 0.4685328 (4.1)
T = Temperature
[°C]
For the temperature categories, the equation is used to calculate the productivity percentage at
the lowest and highest temperature within a category. The average value of these are then defined
as the productivity percentage representing that category.
Category Intervals Min Max Average Productivity
Good 20-23 °C 0.99 1.00 1.00 100 %
Acceptable 18-20 °C 23-35 °C 0.97 0.98 98 %
Unacceptable <18 °C >25 °C 0.94 0.95 95 %
Table 4.2: Temperature Calculations
The equation linking CO2 and productivity is based on the study ’Ventilation and Performance in
Office Work’ by Seppänen et al. (2006)[114][112]. In order to apply this equation, the ventilation
rates were converted to corresponding CO2-level. This was completed by solving q v in Equation 4.2.
C = G q v
+ c o (4.2)
G = 17 · M
[L/h]
C = CO2 – level in the room
[ppm]
q v = Ventilation rate
[L/h]
54 INDOOR ENVIRONMENT IN A DIGITAL FUTURE

c o = Outdoor CO2 – level
[ppm]
where M is the activity level, presumed to be 1.0 met for a person working in an office.
Next, the productivity equation, presented in Equation 4.3, was applied, and the productivity percentages
for the three categories were calculated [113].
P = 0.0188 · ln(x) + 0.9482 (4.3)
x = Average ventilation rate
[L/h]
Category Intervals Min Max x Productivity
Good 0-800 ppm - 11.8 1 1
Acceptable 800-1200 ppm 11.8 5.9 8.9 99
Unacceptable >1200 ppm 5.9 3.4 4.6 98
Table 4.3: CO2 Calculations
Finally, the calculation sheet was modified based on the calculations for the categories defined
in this project. The calculation sheet makes it possible to easily present a productivity percentage
change for the offices.
INDOOR ENVIRONMENT IN A DIGITAL FUTURE 55

CHAPTER 5
Results
Chapter 5 presents the results of the preliminary device evaluation
followed by the IEQ investigation conducted in the three
offices. Furthermore, chapter 5 presents the stakeholder matrix
and the value proposition canvas followed by a presentation
of the developed benchmarking tool. This includes a description
of the IEQ parameters’ weighting, grading scheme, economic
estimations and database concept. Lastly, this chapter
presents the development process of the IEQ report including
the content of the report.

5.1 Preliminary Device Evaluation
Device and Dashboard Usability
The preliminary device evaluation investigated the ease of use, the means of support from the producer
of the device, the user-friendliness of the dashboards and the steps to access the raw data.
The result of this evaluation is an overview and comparison of the usability and performance of the
devices. The ease of use and the means of support from the producer is presented in Figure 5.1. First
the prerequisites and limitations, along with the ease of setup of the devices, were evaluated. The
ease of setup was evaluated as the number of steps in order for the device to be installed and measuring.
RoomAlyzer and IC-Meter have fewer steps, compared to the other devices, because these
devices and accounts were set up by the producers. The means of support from the producer of the
device was crucial when using and obtaining information on the devices. This was evaluated as the
response rate from the producers. Furthermore, the producers of uHoo, RoomAlyzer and IC-meters
were able to provide almost all of the desired information and assist in problems encountered. The
producers of Foobot, on the other hand, were not able to assist in connectivity issues, which resulted
in the device not being included in the study.
In relation to the dashboards presenting the data and providing a possibility to download data, the
preliminary study showed a difference in the latency of the dashboard updates and the number
of steps/clicks to download the raw data and prepare it for analysis. The reason that it takes 42
clicks to download data from the RoomAlyzer dashboard is because the data must be downloaded
individually for each measured parameter. Downloading data from the Sens’it dashboard is not
possible and must therefore be read or copied manually, which will be highly time consuming for
projects with long periods of measurements.
Figure 5.1: Evaluation of device and dashboard usability
60 INDOOR ENVIRONMENT IN A DIGITAL FUTURE

Measurements
The preliminary study compared data from test measurements for the devices. The test measurements
were conducted in an unoccupied meeting room in May 2020 starting at 9am and with a
duration of 24 hours. The aim of the 24 hours test was to compare the measurements for temperature
and humidity for all four devices, CO2 measurements for three of the devices along with TVOC
and noise measurements for two of the devices. The intention of the study was not only to compare
the devices, but also to become aware of the potential differences and the reasons behind these
in collaboration with the producers if possible. Awareness of these were important, as the different
devices were used to represent different zones within the offices. The actual IEQ results were not analysed
or commented upon as the differences between the devices were the focus of this preliminary
study.
Initially, the averages over the 24h period were found for the different devices and parameters measured.
Furthermore, the maximum difference between lowest and highest measured values by two
devices at the same time was found. These key numbers are presented in Table 5.1.
CO2
ppm
TVOC
ppb
Temperature
°C
Humidity
%
Noise
RoomAlyzer 470 240.5 28.0 35.3 41.6
Difference between
lowest and highest average
Maximum difference between
lowest and highest measured
value at specific point of time
Uhoo 487 29.6 26.4 33.9
Sens’it 26.9 39.5
IC-meter 427 27.4 33.1 32.6
dB
60 207.9 1.6 4.6 9.0
128 279.9 2.4 7.5 13
Table 5.1: Key numbers from the 24h measurements
The data for each of the parameters measured by the devices was then plotted on chronological
graphs presented in the following pages. This compares tendencies for the measurements with the
different devices. Similar tendencies during the 24 hours could indicate that the devices use similar
or comparable sensors. Different tendencies could indicate different sensors or sampling methods
within the devices or different quality of the sensors.
Furthermore, box plots, also presented in the following pages, were used to visually display the data
and distribution. The box plots were used to display differences in standard deviation between the
devices. The size of the boxes were used to indicate if the measurements were characterised by high
fluctuation or by steady values.
The price and accuracy for the devices refer to the values and intervals from the market research. The
accuracy is referred to as ”claimed accuracy” as it is solely information from producers as opposed
to scientific tests.
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The average CO2 measurements presented in Table 5.1 indicate lower measurements using the IC-
Meter compared to the uHoo and RoomAlyzer. Figure 5.2 and 5.3 show that the RoomAlyzer had
highly fluctuating measurements compared to the other devices. The fluctuation, according to producers,
is most likely due to the sampling method of the sensors and not the type of sensor. Since all
of the devices use a type called nondispersive infrared sensor for the CO2 measurements. Furthermore,
the use of a smoothing algorithms on CO2 measurements, which is common practise, could
explain the stability of the uHoo and IC-Meter curves. However, these methods are not used by any
of the producers [115] [103] [98]. The IC-meter is higher priced than the other devices and claims to
have a higher accuracy than the other devices within this parameter.
Figure 5.2: 24h CO2 measurements
Figure 5.3: 24h CO2 box plot
62 INDOOR ENVIRONMENT IN A DIGITAL FUTURE

Table 5.1 shows that the average for TVOC measurements with the Roomalyzer was higher than
the uHoo. This can be seen on Figure 5.4 which also indicates different tendencies during the 24
hours. Furthermore, Figure 5.5 shows a greater difference between lowest and highest measured
value for the RoomAlyzer compared to the uHoo. The RoomAlyzer and uHoo have similar price
point and similar claimed accuracy. The difference in the measurements was investigated through
communication with the producers and is most likely due to the different sensors. The TVOC sensor in
the uHoo measures following nine specific VOC’s: a-Pinene, d-Limonene, acetaldehyde, acetone,
hexanal, n-Decane, toluene, formaldehyde and benzene [98]. Whereas the TVOC sensor in the
RoomAlyzer measures all reducing and oxidising gases and is not selective towards specific gases
[115]. This difference meant that special attention was paid to measurements of TVOC with these
devices during the subsequent measurements in the offices.
Figure 5.4: 24h TVOC measurements
Figure 5.5: 24h TVOC box plot
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The average temperature measurements presented in Table 5.1 show a higher average for the Room-
Alyzer and IC-meter compared to the uHoo and Sens’it. Despite the relative differences in the averages,
Figure 5.6 shows similar tendencies for the four curves during the 24 hours. Figure 5.7 shows,
that on average, sens’it records higher temepratures when compared t the other three devices. The
RoomAlyzer and the IC-meter has the highest claimed accuracy for temperature measurements
while uHoo and Sens’it has medium claimed accuracy. The IC-Meter is the most expensive, while
the RoomAlyzer and uHoo is medium priced and the Sens’it is the least expensive.
Figure 5.6: 24h temperature measurements
Figure 5.7: 24h temperature box plot
64 INDOOR ENVIRONMENT IN A DIGITAL FUTURE

Table 5.1 shows that Sens’it’s average relative humidity measurements are higher when compared to
the other devices. This can also be seen on Figure 5.8 which despite Sens’it shows similar tendencies
for the three other devices during the 24 hours. Figure 5.7 shows a higher relative similarity of the
measurements for the Sens’it compared to the three other devices. The RoomAlyzer and the ICmeter
has the highest claimed accuracy for temperature measurements while uHoo and Sens’it has
medium claimed accuracy.
Figure 5.8: 24h humidity measurements
Figure 5.9: 24h humidity box plot
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Table 5.1 shows that the average noise measurements using the Roomalyzer was higher than the
IC-meter. This can be seen on Figure 5.10, which also indicates different data trends and levels of
fluctuation during the 24 hours. The difference was investigated through communication with the
producers and it was most likely due to different sensors. The noise sensor in the IC-meter has a sensitivity
of 32-110 dB [103]. The plot of the IC-Meter data should therefore be interpreted as indicating
that the noise level was 32dB or below in the majority of the 24 hours. The sensitivity for the noise
sensor in the RoomAlyzer was not obtained. The price level of the IC-Meter is high and the price level
for the RoomAlyzer is medium. None of the producers provided the accuracy for the noise sensors
in the devices. The difference meant that special attention was paid to measurements of noise with
these devices during the subsequent measurements in the offices.
Figure 5.10: 24h noise measurements
Figure 5.11: 24h noise box plot
66 INDOOR ENVIRONMENT IN A DIGITAL FUTURE

5.2 IEQ Investigation
The following part will present the analysis of the objective data in the form of measurements and
subjective data in the form of occupant questionnaires, both obtained during the investigations of
the three offices. The investigations were conducted in May and June 2020 and with a duration of
five weekdays for each office.
Based on the usability evaluation and measurement comparison in the preliminary study it was decided
to use the RoomAlyzer, uHoo and IC-meter for measurements in the three offices. Since the
different zones in the offices were measured with different devices, special attention was paid to the
TVOC and noise measurements due to the differences seen in the 24 hour study.
The time percentage within the three previously presented categories: good, acceptable and unacceptable
were calculated for each office and presented in accumulated bar charts. The categories
are indicated with green, yellow and red. The percentage of time in the different categories
are presented along with the percentage of occupants experiencing symptoms, which might be
related to a specific parameter and the percentage of dissatisfied occupants based on complaints.
Data presentation
The results are presented for each zone within the offices and indicated by names where ’Office1_1’
for example is zone 1 in office #1. Figure 5.12, 5.13 and 5.14 presents the results of CO2, TVOC and
PM2.5 which are the parameters within the IAQ category.
Figure 5.12: CO2 results
Regarding the CO2 measurements, it was observed that none of the offices had any measurements
in the category ’unacceptable’, but as seen in Figure 5.12 most of the offices had zones with measurements
in the category ’acceptable’. Furthermore, it was discovered that the CO2-concentration
INDOOR ENVIRONMENT IN A DIGITAL FUTURE 67

was highest for zone 1 in each office. The reasons could be, that the entrance to the offices is all
in zone 1. Consequently, these zones might be more occupied during the day. Zone 3 in office #2,
also has a higher percentage of CO2 measurements in the category ’acceptable’, which could
be due to the connecting meeting room occupied by several people at specific times during the
days. Furthermore, it is interesting how the CO2 measurements in zone 1 in office #3 has the highest
percentage of time in the category ’acceptable’, as it was observed that the workstations in this
zone were not occupied during the investigation. However, this zone contained the entrance, a
coffee machine, and a small meeting table, which might cause more occupants to be in this zone.
The amount of occupants who experience symptoms varies throughout the zones and no indication
of a correlation between the measurements and the symptoms was observed. Anyhow, it must be
acknowledged that the experienced symptoms could also be related to other parameters or factors
than the CO2-concentration. The only complaint related to IAQ is odour. Zone 2 in office #1, is the
only zone with odour complaints. As well as for the symptoms, complaints can be related to other
factors than IEQ.
Figure 5.13: TVOC results
Regarding the TVOC measurements, most of the zones in the offices were within the category ’good’.
Despite this, zone 2 in office #3, has the majority of time within the category ’acceptable’. The
preliminary study indicated that the RoomAlyzer measures higher values than the uHoo, because it
measures more compounds then the uHoo. Hence this could also explain the higher values in zone
2 in office #3 since the RoomAlyzer was used to measure this zone. Comparison of measurements
in the 24 hour study and measurements in the three offices however indicated that the difference
between these two devices were smaller during the measurements in the offices than during the 24
hour study. This comparison can be seen in appendix G.
68 INDOOR ENVIRONMENT IN A DIGITAL FUTURE

Figure 5.14: PM2.5 results
The uHoo was not included in the investigation of office #1 because of the captive portal network in
the office. Therefore, are no PM2.5 measurements results for this office. Anyhow, the symptoms and
percentage of dissatisfied for this office have still been included in the presentation. The majority
of the PM2.5 measurements are within the category ’good’, which indicates that the experienced
symptoms might be caused by other parameters or factors.
Figure 5.15: Temperature results
Figure 5.15 presents the temperature measurements. High temperatures are seen in the offices. The
INDOOR ENVIRONMENT IN A DIGITAL FUTURE 69

majority of the zones in the three offices only have a small percentage of measurements in the category
’good’. This indicates a problem with overheating in all of the investigated offices. Several
complaints related to temperature were observed. Especially in office #2, which is the office with
the highest percentages of dissatisfied occupants.
Furthermore, the results indicate that the temperatures are higher for the zones further away from
the entrance. For both office #1 and #2, the zones are placed in continuation of each other. Zone
1 is for both cases the zone with the entrance. Reasons for the higher temperature in zone 2 and
3 can be due to a higher air change closer to the entrance. Office #3 zones are not placed in
continuation of each other. Zone 1 is the zone including the entrance, while zone 2 and 3 are placed
in either east direction or west direction. Zone 1 with the entrance still contains lower temperature
but furthermore, it was discovered that the zone with the West direction (zone 2) have a higher
percentage of temperatures in the unacceptable category than the zone in the East direction. This
might be a result of the sun’s path. For the stakeholders, involved in the process, knowledge about
peaks during the day might be interesting.
Figure 5.16: Humidity results
The humidity measurements showed, that humidity was not a problem in the offices. However, a few
complaints related to humidity were obtained. Yet, it must be acknowledged that these complaints
can be linked to the temperatures as well. As with the temperature, the percentage of dissatisfied is
highest in office #2.
70 INDOOR ENVIRONMENT IN A DIGITAL FUTURE

Figure 5.17: Noise results
The preliminary study indicated that the RoomAlyzer measures higher noise levels than the IC-Meter.
Hence this could also explain the higher values in zone 2 in office #3 as RoomAlyzer was used to
measure this zone. However, comparison between measurements in the 24 hour study and measurements
in the three offices indicated that the differences between measurements with these two
devices turned out to be smaller during the measurements in the offices than during the 24 hour
study. This comparison can be seen in appendix G.
Furthermore, it is important to underline that the good category for noise is hard to obtain, as it is
based on the limit for background noise from building services and not occupants. Therefore, a
higher percentage in the acceptable category is not as ”bad” in this case.
An important part of the following benchmarking tool is visualising the results for relevant stakeholders
providing information they can use. Thus, it is important to select the relevant stakeholders and to
understand their pains and requests.
INDOOR ENVIRONMENT IN A DIGITAL FUTURE 71

5.3 Stakeholders and Value
Stakeholder Matrix
Figure 5.18 presents the stakeholder matrix for the situation where a company, who owns and is the
main user of a building, wishes to improve their IEQ or renovate their office. This is representative of
the office buildings used in this project. Additionally, a stakeholder matrix for the situation where a
company rents an office space was also constructed and can be seen in Appendix C.
Figure 5.18 shows how the stakeholders involved in a renovation process or IEQ improvement are from
various sectors. Facilitating collaboration between these stakeholders could therefore help break
down the cross-sectoral knowledge silos.
The crowd which can be seen as potential stakeholders include craftsmen, suppliers, researchers
and engineers. The context setters, which can influence the development, use and promotion of
a benchmarking tool, are consultants and authorities. The subjects are the occupants because of
their high interest in a improved IEQ leading to heightened personal well-being and health. However
they have less influence on the major decisions regarding renovation of the office. The players, who
are the stakeholders with the highest interest and power, are the building owners in this case. Building
owners could help improve the power of the occupants by including their opinions and perceptions
of the IEQ in the decision-making process.
Figure 5.18: Stakeholder ’Power/Interest’-matrix
Since the occupants and building owners are amongst the stakeholders with the highest interest they
have been investigated further in this project. Because of the building owners high power in decisionmaking
regarding their office buildings, they have been the focus area concerning stakeholders
and their point of views on a possible benchmarking tool for IEQ. Therefore, building owners were
interviewed in order to gain knowledge about pains and gains related to improving IEQ.
72 INDOOR ENVIRONMENT IN A DIGITAL FUTURE

Interviews with Decision-Makers
Based on the interviews with the decision-makers, which can be found in appendix E and F, a Value
proposition canvas (VPC) was created. The VPC, which is presented in Figure 5.19, was created in order
to ensure an alignment with the building owners’ needs and the properties of the benchmarking
tool.
In the interviews, the building owners expressed interest in investigation of status quo in the form of
IEQ audits and in improvement of the IEQ. The benchmarking tool should therefore include guidance
on investigation methods and/or simply provide this as a service along with the benchmarking tool.
A challenge that the building owners described was the complexity of a renovation process, especially
the lack of knowledge and lack of access to valid information. The benchmarking tool should
therefore propose a simple and easily understandable tool, explanation of IEQ aspects and access
to information, possibly in the form of an open database. Furthermore, they mentioned that problems
were often solved long after they occurred and that they were solved by trial and error in most
cases. The benchmarking tool should therefore include proactive suggestions and justifications for
IEQ improvement decisions. The last but most frequently described challenge was the economic
compromises that the building owners faced and the lack of knowledge on the economic aspect
of IEQ. The benchmarking tool should therefor shed light on and include this aspect.
The positive outcomes that the building owners expected from a renovation or IEQ improvement
included a healthier and/or more sustainable profile and proof. The benchmarking could therefore
include a form of certification. Moreover, the building owners expected healthier and happier
employees, and hence, occupant inclusion is important for the benchmarking tool. The building
owners explained that by renovating or improving the IEQ, they would expect a higher productivity
and economic gains. The benchmarking tool should therefore include economic estimations, which
can show the economics gains of improving the IEQ and hereby productivity of the occupants.
Figure 5.19: Value Proposition Canvas based on interviews
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5.4 Benchmarking Tool
Based on both the stakeholder matrix and interviews with decision-makers, a benchmarking tool has
been developed. In the following part, the benchmarking tool and the reasons for its creation will be
described. This includes the weighting of parameters and categories, the subjective and objective
calculations behind the rating, economic estimations, and the future database.
Weighting
The weighting of IEQ parameters is not predetermined. There is no overall weighting used by the
different studied certification and benchmarking tools. The composed weighting in this study is inspired
by NABERS, research papers including a Green Building study, IQ compass, and DGNB. The
two IEQ categories with the greatest weighting percentages are IAQ and thermal comfort. IAQ is
assigned the greatest percentage as it has the most parameters to measure. Additionally, it has
been discovered to lead to more complaints. The weighting can be seen in Figure 5.20.
Figure 5.20: IEQ weighting
The four categories are further divided into subcategories, consisting of both objective data and
subjective data. The objective data are measured with the IoT devices and include measurements
of IEQ parameters such as temperature, humidity, CO2-concentration, noise, Pm2.5, and other pollutants.
While the subjective data is obtained by questionnaires and present the occupants’ experienced
IEQ. The subjective data includes SBS symptoms, experienced conditions, and user control.
Each subcategory results in a score contributing to a final percentage describing the offices’ IEQ.
The weighting of the subcategories can be seen in Appendix H.
The objective data is divided into three categories: good, acceptable, and unacceptable. In order
to calculate the objective subcategories scores, the percentage of time within the three categories
is multiplied with a factor as seen in equation 5.1.
Timein ′ Good ′ · 1 + Timein ′ Acceptable ′ · 0.5 – Timein ′ Unacceptable ′ · 1 (5.1)
Likewise, the subjective data is divided into four categories: Not in the past four weeks, 1-3 days in
the past for weeks, 1-3 days per week in the past four weeks, every day during the past four weeks.
74 INDOOR ENVIRONMENT IN A DIGITAL FUTURE

Later named: Never, monthly, weekly, and daily. To calculate the subjective subcategories scores,
the first and fourth category is multiplied with a factor 1, describing 20 out of 20 workdays, the second
category is multiplied with 0.1, describing 2 out of 20 workdays, and the third category with a factor
0.4 describing 8 out of 20 workdays. The equation used to estimate the score can be seen in equation
5.2.
Never · 1 – Monthly · 0.1 – Weekly · 0.4 – Daily · 1 (5.2)
Grading
The final percentage is calculated and the offices can be evaluated. The evaluation is based on a
grading scheme, a radar, and outlined in a detailed report. The grading scheme has been developed
in light of the market research. As stars were the most common grading scheme, they were
selected. The offices are evaluated on six levels inspired by NABERS. The distribution of stars and their
respective percentage levels can be seen in Table 5.2.
[0-40%] = Poor IEQ =
]40-50%] = Below Average IEQ =
]50-70%] = Average IEQ =
]70-80%] = Good IEQ =
]80-90%] = Excellent IEQ =
]90-100%] = Market leading IEQ =
Table 5.2: Grading distribution
In addition to the grading scheme, a radar has been developed to show the score distribution of
each of the categories and subcategories. The radar aims to create a quick and simple overview
and provide a more detailed justification of the reason behind the office’s grading score. The radars
were developed for each of the offices and are presented in Figure 5.21 and Figure 5.22.
(a) Office#2 (b) Office #3
Figure 5.21: Radar for office #2 and #3
INDOOR ENVIRONMENT IN A DIGITAL FUTURE 75

Figure 5.22: Radar office #1
As seen in Figure 5.22, the radar illustrates the four categories’ weight distribution and furthermore
the weighting of their subcategories. In the middle of the radar, the office’s final score is illustrated.
As seen in the figures the office with the highest score is office #1, while office #2 and office #3 almost
scored similarly. Office 1’s grading is four stars, while office 2 and 3 only scores three stars. Furthermore,
the radars visualise the low scores in the category: thermal comfort, which is mostly due to the
observed overheating in each of the offices.
76 INDOOR ENVIRONMENT IN A DIGITAL FUTURE

Economic Estimations
In addition to the rating, the economic benefit of improving productivity has been investigated. A
percentage predicting a potential productivity increase has been calculated for both offices and
their zones. The calculations are based on the project ’Totalværdi Indeklima (2017)’ [110][110].
Office #1 Office #2 Office #3
Total productivity increase
3,8 % 3,7 % 3,5 %
Zone 1 Zone 2 Zone 1 Zone 2 Zone 3 Zone 1 Zone 2 Zone 3
3,4 % 4,2 % 2,1 % 4 % 5 % 2,6 % 4,3 % 3,7 %
Table 5.3: Potential productivity increase
Table 5.3 presents the potential productivity increases. The results highlight the zones with the greatest
potential productivity improvements. Furthermore, the Table illustrates how office #1 is the office
with the greatest productivity increase percentage, although it is the office with the best grading.
However, it is important to acknowledge that the results are only based on objective measurements
of temperature and CO2-concentrations and they do not include subjective data from this office
study. Office #1 is the office with the least complaints and symptoms related to both temperature
and CO2, whereas office #2 is the office with the most complaints and symptoms.
Moreover, another important determinant is the measuring period. In this case, the period was a five
days period in either May or June where the weather was sunny. A five days period during summer
does not reflect the office during an entire year and the measuring period should for subsequent
testing be extended or repeated throughout the year.
In addition to calculated percentages, a graph was constructed illustrating the potential cost saving
due to improved productivity for each office. The graph is illustrated in Figure 5.23. The graph can
be described by Equation 5.3.
Employees · Currently yearly salaries · Potential productivity increase percentage (5.3)
The graphs provides decision-makers with an idea of potential saving due to increased productivity.
The cost saving depends on the average monthly salary for the occupants in the offices. If office #1
occupants’ salaries in average are 40.000 DKK monthly, the office could yearly save approximately
up to 110.000 DKK yearly by improving the temperature and CO2-concentration. The graph can
thereby be a help in decisions linked to improving IEQ.
INDOOR ENVIRONMENT IN A DIGITAL FUTURE 77

Figure 5.23: Potential cost saving savings for office #1
Database
The benchmarking tool should include a database, where stakeholders can share knowledge and
retrieve guidance related to the problems occurring in their offices.
The purpose of the database is to avoid stakeholders’ trial and error, and instead, provide them
with knowledge about solutions which worked or did not work in other offices. Furthermore, the
database should provide opportunities to benchmark offices, and compare different trials in similar
offices to find the best solution. This could include everything from interior layout to window types.
The database should contain data from offices from all over Denmark in order to represent a great
variety of offices regarding size, year of construction, building materials, occupancy, means of use
etc.
The importance of a such database lies in its ability to provide stakeholders with knowledge, experiences,
innovative ideas, and solutions.
5.5 IEQ report
After the development of the benchmarking tool, a template for an IEQ report was developed. This
template was used to create a detailed IEQ report for each of the three offices. The purpose of the
report is to provide stakeholders with detailed information concerning their office and possible IEQ
issues. The report was constructed like a newspaper article, with the most important first to obtain
78 INDOOR ENVIRONMENT IN A DIGITAL FUTURE

the undivided attention, and then slowly getting more detailed and ending with a summary. As presented
in Figure 5.24, drafts of the report were tested during two feedback session with stakeholders
related to the three offices, and then a final report was developed. The report includes visualisation
of both the objective and the subjective data, peaks and an encyclopedia.
Figure 5.24: IEQ Report development process
Feedback sessions
The feedback sessions were conducted as an informal presentation were the stakeholders were encouraged
to ask questions and comment upon the content. During the feedback sessions the stakeholders
comments and suggestions were noted or written on a printed version of the IEQ report as
seen on Figure 5.25 and 5.26.
Figure 5.25: Feedback session #1 Figure 5.26: Feedback session #2
INDOOR ENVIRONMENT IN A DIGITAL FUTURE 79

Feedback from the first session included comments on the level of detail. The decision-makers were
interested in detailed graphs and information for each zone in the office and not just the whole
office as the first draft presented. However, they liked the introductory overview with graphs for the
whole office. Regarding the grading scheme consisting of 1-6 stars, they mentioned that they would
like to see the different percentages that would lead to different number of stars. For the plots of
IEQ measurements and understanding hereof, they would like the graphs to include the red area
which is the category ’unacceptable’, in order to see if they were close to reaching it. Furthermore,
they were interested in the peaks on the graphs and the exact day and time for these, since they
wanted to be able to understand if the peaks were related to the cleaning, weekly meetings or other
scheduled factors. The decision-makers mentioned that a simpler presentation of the percentage
of occupants with symptoms and complaints would be useful. Lastly, they mentioned that a form of
summary of the results would be helpful in order to understand their IEQ issues better.
Feedback from second session included minor improvements. The feedback was very positive, and
the decision-makers were positively surprised about their results. Furthermore, they easily understood
the flow of the report and its content. Received feedback included were to include peaks in each of
the zone graphs as well as the overall graphs. Furthermore, they were interested in knowing in which
zones the complaints occurred. In the first feedback session, summaries were requested. These were
made before this feedback session and the response was very positive. The decision-makers said the
summaries aided them en understanding of the results.
Content of the report
First, the decision-makers were presented with the results of their office. This includes both the grading
scheme and the appurtenant radar. Figure 5.27 illustrates an example of the presentation of the
grading scheme.
Figure 5.27: Grading scheme results for office #1
After presenting the granted rating for the office, the four IEQ categories’ scores are presented, as
seen in Figure 5.29. The purpose of this is to provide the stakeholders with a quick overview of the IEQ
categories with either a low or high score. Furthermore, it works as an introduction to the following
parts of the report, where each of the four IEQ categories data will be presented.
80 INDOOR ENVIRONMENT IN A DIGITAL FUTURE

Figure 5.28: Office #1’s grading scheme results for the four IEQ categories
Each of the IEQ categories’ presentation starts with a short descriptive text to guide the reader and
then it presents the symptoms and complaints related to the category. Furthermore, it has a short
explanation of what the following part will include: peaks, symptoms, complaints, and a summary.
The summaries includes the considerations made during the IEQ investigation of the data. In addition
to this, the presentation contains smileys representing the three measurement categories: good,
acceptable, and unacceptable. An example hereof can be seen in Figure 5.29.
Figure 5.29: Grading results for IEQ categories
INDOOR ENVIRONMENT IN A DIGITAL FUTURE 81

The more detailed part of the category is then illustrated with graphs for each of the measured
parameters related to the category. The graphs show the measurements within the five days measuring
period. First, the results for the whole office are presented in one graph. Thereafter, each zones
measurements are presented individually. An example of the graphs is illustrated in Figure 5.30.
Figure 5.30: CO2 measurements for office #1
The graph illustrates the CO2 measurements for office #1. As office #2 was divided into two zones,
both zones are illustrated in this graph. The graph illustrates the measurements during office hours.
To help the reader understand the measurements, the three measurement categories’ intervals are
highlighted in the background of the graph. Likewise, the peaks are highlighted and their times are
listed in the report. Furthermore, the graphs contain the smileys and percentages representing each
of the measurement categories.
The graphs are accompanied with the related symptoms. The visualisation presenting the symptoms
is presented in Figure 5.31. The visualisation shows how many percentages of the occupants, who
experience symptoms, which could be related to the measured parameter. The symptoms can be
experienced either daily, weekly, monthly, or never.
Figure 5.31: Symptoms related to CO2 for office #1
82 INDOOR ENVIRONMENT IN A DIGITAL FUTURE

Moreover, the graphs and symptoms are accompanied by related complaints. The visualisation illustrating
the complaints is presented in Figure 5.32. Like symptoms, the complaints can be experienced
either daily, weekly, monthly or never.
Figure 5.32: Complaint related to CO2
The presentation of the parameter’s measurements and related symptoms and complaints ends with
a summary. The summary sums up what the previous pages showed, and what was discovered in the
IEQ investigation. Afterwards, another parameter or IEQ category is presented, and the productivity
increase percentage for the office. All of the reports are presented in Appendix J.
INDOOR ENVIRONMENT IN A DIGITAL FUTURE 83

CHAPTER 6
Discussion
Chapter 6 presents an interpretation of the achieved results
along with a description of the significance of the findings of
this project. Furthermore, it sheds light on the uncertainties and
the limitations of the use of IoT devices and IEQ benchmarking.
Chapter 6 discusses the variances in results, measurement
period, GDPR, privacy and occupant questionnaires. Furthermore,
it comments upon the weighting of IEQ parameters, the
identified and involved stakeholders , and the economic estimates.
Lastly, it describes the future implication of the project
focusing on statistical modelling and sustainability.

6.1 IEQ Investigation
Preliminary device evaluation
The preliminary device evaluation concluded that the ease of setup was dependent on the power
source and connectivity. The devices with battery and a sim card like Sens’it and RoomAlyzer had
fewer setup steps and were easier to install. These devices could be installed faster and more discreetly
since they did not need WiFi or extension cords for a power supply. Moreover it was concluded
that the calibration time is essential if the devices are used in several different locations. Regarding
this, RoomAlyzer, Sens’it and IC-Meter are preferred as they are calibrated from the producer and
has auto-calibration when in use.
In order to minimise the number of devices to be used, it is also preferable to select as few devices
as possible which alone or collectively cover all parameters planned to be measured. Furthermore,
the communication and service provided by the producers turned out to be crucial for this project.
RoomAlyzer, uHoo and IC-Meter were the most reliable regarding response rate and helpfulness.
Based on the conclusions of the preliminary device evaluation it is recommended that, if a number of
IoT devices should be used in the PhD study, Foobot and Sens’it should not be used. IC-Meter could
be used, however it only measures four parameters. The recommended combination of devices is
uHoo and RoomAlyzer which collectively measure 12 relevant parameters. For uHoo, whose main
focus is IAQ, two devices would be ideal for an office of 100 m 2 . For RoomAlyzer, which has a broader
IEQ perspective, one device should be used on each workstation if the light, occupancy or noise is
measured. Otherwise, two devices for an office of 100 m 2 is sufficient.
Variances in Measurement Results
The use of IoT devices for IEQ measurements in the PhD study should not be seen as a substitute
for highly precise measurement instruments, but rather as an alternative providing less accurate but
more immediate and more easily accessible IEQ data.
In this project more attention was paid to usability and inclusion of various parameters rather than to
accuracy and precision. This will always be compromised when measuring in office environments,
where occupant behaviour can influence measurements and conditions are changing. However,
it is important to have knowledge about the validity of the measurements in order to determine if
variety in results could be derived from the instruments or incorrect use hereof. Tests of the devices’
actual accuracy and comparison between different devices in a closed and controlled environment,
and with highly precise instruments used as reference values, would provide an interesting
and important perspective of these IoT devices.
Some of the devices used in this project can cover areas of up to 100 m 2 and in some cases more.
Despite this, it was decided to divide the offices into 2-3 zones of approximately 20-50 m 2 for greater
precision, and to have the possibility to detect differences in the office’s IEQ. For projects where
even greater precision is desired, the offices could be divided into more zones or each workstation
could represent a zone. Defining each workstation as a zone is especially useful when measuring
occupancy, light, and noise since these can vary greatly from one workstation to another.
88 INDOOR ENVIRONMENT IN A DIGITAL FUTURE

Measurement Period
The measurement period in the offices in this project was five weekdays per office. With a sampling
frequency of 1-15 minutes depending on the device, this resulted in between 180-2700 data points
per device per office. While this amount of data is enough to perform statistical analysis on the IEQ,
it is not enough to make general conclusions about the IEQ in the offices. For projects with a greater
time frame the measurement period could be expanded to one whole year as in LBC’s certification,
or to multiple individual measurements distributed evenly throughout the year.
GDPR and Privacy
The strategy for DTU 2020-2025 focuses on technology for people, which means that projects and
technologies should benefit and be used in favour of the people [116]. In an IEQ measurement
perspective, this means that focus on ethics and privacy are important aspects concerning the use
of IoT devices and storage of data.
For this project, the GDPR compliance and privacy policies for the devices and dashboards were
investigated. Even though all of the devices complied with the GDPR, it is still important to consider
the ethical aspects. There is often a fine line between measurements and surveillance, and the
objectives of the measurements and the way of conducting them are often the determining factor.
In this project, the objectives of the measurements are the possibilities to improve the IEQ which
would benefit the occupants’ health and well-being.
Occupant Questionnaires
Regarding the use of questionnaires to obtain data on the perceived IEQ, it was decided to use
anonymous surveys in this project. This was done in order to avoid that the respondents would elude
answering some questions because of concerns regarding the consequences of their answers. However,
it should still be taken into account that answers are solely based on the respondents’ perception
and memory, which means they might not be a true reflection of reality. For instance, it could
be difficult for occupants to remember the amount of days with symptoms in the past four weeks.
Another aspect of the use of questionnaires is the response rate. In this project a 100% response rate
was obtained. However, this might not be the case in similar or larger projects. This could lead to a
false positive or false negative average of perceived IEQ, and should be taken into consideration.
In a case where a low response rate is obtained, it could be that only occupants who were over
or under average satisfied responded. This would also lead to false positive or negative average of
perceived IEQ. To avoid these false positives or negatives a minimum response rate could be set as
an requirement. A rule of thumb in questionnaires for scientific use is that a response rate of 60% or
higher is acceptable [117].
6.2 Benchmarking tool
IEQ weighting
Since there is no existing definitive weighting of the four IEQ categories, the weighting often varies
within different benchmarking tools. The weighting for this benchmarking tool was developed based
on the market research and research papers. The weighting includes both objective and subjective
INDOOR ENVIRONMENT IN A DIGITAL FUTURE 89

data in order to include as many aspects as possible. The objective and subjective data are subcategories
with the IEQ categories contributing to their associated IEQ category’s final score.
The weighting of some of the subcategories were not representative for the entire office. An example
hereof is light. Since light was only measured by one device in this project, it would not be
representative for the whole office. However, the light level as a subcategory is included in the rating
calculation sheet, so the benchmarking tool can be applied in other projects where light levels are
measured at more points. The offices in this study were granted top scores in this subcategory. Furthermore,
the visual comfort was defined by the distance from the workstations to a window, artificial
light at workstations and related symptoms and complaints.
In a future IEQ investigation, light levels should be measured at each workstation to make it representative
of the visual comfort. The developed calculation sheet for the rating has been created so
it can easily be modified in order to match updated guidelines or an adjusted weighting.
Stakeholder involvement
The stakeholders relevant to an IEQ improvement were identified through a stakeholder analysis. Occupants
and building owners are amongst the stakeholders with the highest interest, but as building
owners also have high power, they are the decision-makers in a renovation process or improvement
of IEQ. Thus, the building owners of the investigated offices were interviewed.
A great deal of this project has relied on stakeholder involvement. The stakeholders were involved
to get an understanding of the challenges they might face before renovating or improving IEQ,
but also to get feedback on the developed benchmarking tool and report. However, both of the
companies are related to or within the building industry. This might have led them to have more
interest in the project and more knowledge about renovation and IEQ compared to building owners
and occupants who do not work in this industry. While the concept of the benchmarking tool and
IEQ report might have been easier for them to understand, they could also be more critical in the
feedback sessions. Involving decision-makers from other industries to ensure that the benchmarking
tool and IEQ report features all relevant information would be interesting.
In addition to this, since all the decision-makers involved in the the project were building owners, the
tenants and administration companies are not represented. It would have been interesting to conduct
a feedback session with these stakeholders, and include them in the development process of
the benchmarking tool and report. This could ensure that the benchmarking tool would be relevant
for several types of decision-makers.
Regarding the stakeholders it would be interesting to also include researchers, consultants, authorities
etc. in the process of development. This could ensure that the database and benchmarking
tool could help breaking down the knowledge silos across sectors and benefit more stakeholders.
The ideal outcome of a database and benchmarking tool would be, that it could not only inform
but also inspire different stakeholders to collaborate in finding new solutions for better IEQ in offices.
Moreover, considering how to retain a positive view on data and knowledge sharing could be explored.
Transparency in the building industry could allow for better collaboration and it is therefore
important to keep the building owners willing to share data on their buildings.
90 INDOOR ENVIRONMENT IN A DIGITAL FUTURE

Economic estimates
Regarding the economic aspect of the benchmarking tool, the estimates in this project are only
based on the measurements of CO2 and temperature. As more research about IEQ and IEQ parameters
are conducted, it would be interesting to explore, whether more parameters or data could
be included as well. This could be both objective data and subjective data. Occupants that complaint
about the IEQ might be less productive. Furthermore, it could be interesting to incorporate the
economic calculations more in the benchmarking tool and in statically models.
6.3 Future implications
Statistical modelling
As the data set in this project was relatively small, no statistical/predictive models were developed.
However, as the database expands actual benchmarking would be possible. As a part of the benhcmarking
it would be interesting to apply statistical models on collected and aggregated data.
Statistical models could be used to diagnose and forecast using IEQ data, symptoms, complaints
and implemented solutions. Thereby, decision-makers would be able to explore which solutions entails
better IEQ along with happier and healthier occupants. The next step in investigation and automation
through IoT devices would be to develop algorithms and rule-based actions based on the
IEQ data.
Sustainability
As the world moves towards a greener future, it would be relevant to include a sustainability perspective
in the benchmarking tool and database. Many companies wish to appear sustainable.
Whether this would require another benchmarking tool or not is uncertain. As the market research
on benchmarking tools already includes certification and benchmarking focusing on sustainability,
a tool or a cooperation with one of these, for instance DGNB, which is the most common certification
in Denmark, would be interesting. This would also be a part of breaking down the knowledge
silos across different sectors and would in the end benefit even more stakeholders.
INDOOR ENVIRONMENT IN A DIGITAL FUTURE 91

CHAPTER 7
Conclusion
Chapter 7 describes the final conclusions of the project and
the contributions to the PhD study. It presents conclusions related
to IoT devices and the IEQ investigation through measurements
and questionnaires. Moreover, it describes the developed
benchmarking tool and IEQ report based on feedback
from identified stakeholders

7.1 Fulfilment of objectives
The fulfilment of the objectives in this project consisted of two parts. One part focused on measurement
devices and IEQ analysis. Another part focused on stakeholders and the development of a
benchmarking tool including an IEQ report. The outcome, of the two parts combined, was a greater
understanding of both measurements, visualisation, and benchmarking of IEQ in offices.
Benchmarking investigation
The characterisation and comparison of existing benchmarking tools resulted in an overview of 21
benchmarking tools and certifications. The majority of the investigated tools and certifications included
all IEQ categories and the majority used stars as grading scheme.
IoT device investigation
The characterisation and comparison of available technologies within IEQ measurement devices
consisted of a market research including 21 IoT devices and a preliminary study of five IoT devices.
The market research indicated that higher priced devices have higher accuracy. The preliminary
study concluded that number of measurable parameters, power source, connectivity, calibration
time, service provided by the producer, and data accessibility were important aspects. Furthermore,
the recommended devices for measurements in offices are the RoomAlyzer and uHoo.
IEQ investigation
The collection of IEQ data in office buildings in this project was conducted in three Danish offices
during May-June 2020. The duration of the measurements was five days per office. Furthermore,
questionnaires were distributed to the occupants in the offices. The results, which were later used
in the developed benchmarking tool, indicated no issues with PM2.5 and humidity in all offices, minor
issues with the CO2, TVOC and sound in most offices, and major issues with temperature in all
offices. Furthermore, several symptoms related to CO2, PM2.5 and TVOC were registered, however
few complaints on air quality were made in any of the offices. Several symptoms related to temperature
and humidity were registered, and complaints caused by thermal comfort were made in all
offices. Some symptoms related to noise were registered, however few complaints related to noise
were made in any of the offices.
Stakeholder analysis
Building owners were identified as the most relevant stakeholders in this context. Through interviews,
their challenges were found to be the complexity of a renovation process, lack of knowledge, limited
access to valid information, and economic compromises.
Benchmarking tool and IEQ report
The developed benchmarking tool were based on the four IEQ categories: IAQ (35%), thermal comfort
(30%), acoustic comfort (20%), and visual comfort (15%). The tool included a grading scheme
consisting of 1-6 stars. To provide the building owners with a more detailed review of their offices an
IEQ report were developed. The report includes a radar, which features the four IEQ categories as
well as the related subcategories. Additionally, it presents economic estimates related to occupants’
productivity.
96 INDOOR ENVIRONMENT IN A DIGITAL FUTURE

Feedback sessions
The benchmarking tool and IEQ reports were evaluated in feedback sessions with decision-makers
and subsequently optimised. The IEQ report, which was designed to be simple and understandable,
starts with an introduction and then illustrates the symptoms and complaints related to the IEQ
category. It then illustrates the IEQ data in graphs and visualisations, and ends with a summary explaining
the results to the decision-makers. Furthermore, the report contains an encyclopedia, where
parameters are explained.
7.2 Fulfilment of overall purposes
Through the fulfilment of the objectives, this project has contributed with an investigation and evaluation
of IoT devices useful for the PhD study. Furthermore, it provided insights on relevant stakeholders
and their motivation and concerns towards IEQ databases and benchmarking tools. Moreover, it has
presented a benchmarking tool which could potentially be used in the PhD study or as framework
for development of a benchmarking tool and database.
The work related to this project has resulted in a greater understanding of IEQ related issues in offices.
It has provided the possibility to explore IoT measurement devices and given an understanding of
possibilities and limitation of these devices. The project has provided a solid background for working
with indoor environment in a digital future. Lastly, it has suggested means to make IEQ parameters
and related issues visible, measurable and understandable to occupants and building owners.
INDOOR ENVIRONMENT IN A DIGITAL FUTURE 97

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106 INDOOR ENVIRONMENT IN A DIGITAL FUTURE

Appendix

APPENDIX A
Desk Study Sensors
Device
type
Price
DKK
CO2
± ppm
Temperature
± ◦ C
RH
± ◦ C%
Noise
±dB
Light
± Lux
VOC
± ppb
PM2.5
± µg/m 3 Other
Polutants
Roomalyzer [97] Commercial 1795 45 0.2 2 B NB-IoT
Power
source
Occupancy
Connectivity
TheO [77] Residential 1026 B 1 M
uHoo [78] Residential 2230 50 0.5 3 10 5 P
Awair [79] Residential 1200 75 0.2 2 10 15
Awair omni [80] Commercial 950 75 0.2 2 10 15
Huma-i [81] Residential 1000 B
Foobot [82] Residential 1300 1.0 5 10 4 P
Air mentor [83] Residential 2170 0.1 1 B
P
Sens’it [84] Experimental 522 0.5 4
B
Temptop [85] Residential 900 B
Wi-Fi
Bluetooth
Wi-Fi
Bluetooth
Wi-Fi
WPA
Wi-Fi
Bluetooth
Wi-Fi
Bluetooth
Wi-Fi
Bluetooth
Sigfox
Netatmo [86] Residential 1279 50 0.3 3 Wi-Fi
Laser Egg [87] Residential 1330 1.0 1 B 8 H Wi-Fi
Wave Plus [88] Residential 1878 30 0.1 1 B 1.5 Y Bluetooth
Air Visual [89] Residential 2000 B 4 H Wi-Fi
B Wi-Fi
IC-Meter [118] Commercial 4306 0.3 2
P LoRa
RYSTA [91] Commercial B 1 Y NB-IoT
Iclever [92] Residential 819 0.3 3 B Wi-Fi
Eve room [93] Residential 670 B Bluetooth
Sigfox
Hummbox [94] Commercial 2232 50 0.2 2 B 5 Y
LoRa
INSAFE+ [95] Residential 65 0.2 1 B 10 Y Sigfox
SIGLINK [96] Commercial 0.2 2 B 5 Y Sigfox
Power source
Battery life
P = Plugged in B = Battery H = Hours W= weeks M = months Y= Years Unknown value =
Market research on IoT devices with known values and details
110 INDOOR ENVIRONMENT IN A DIGITAL FUTURE

APPENDIX B
Questionnaire
INDOOR ENVIRONMENT IN A DIGITAL FUTURE 111

112 INDOOR ENVIRONMENT IN A DIGITAL FUTURE

INDOOR ENVIRONMENT IN A DIGITAL FUTURE 113

114 INDOOR ENVIRONMENT IN A DIGITAL FUTURE

INDOOR ENVIRONMENT IN A DIGITAL FUTURE 115

116 INDOOR ENVIRONMENT IN A DIGITAL FUTURE

APPENDIX C
Stakeholder matrix
Stakeholder matrix for tenants.
INDOOR ENVIRONMENT IN A DIGITAL FUTURE 117

APPENDIX D
Interview guide
Navn:
Rolle:
Arbejdsområde:
Questions related to the VPC customer segment: job(s)
Har I lavet nogle renovering, tilbygninger og ændringer de seneste år/eller prøvet at forbedre indeklimaet?
Hvis ja: Hvilke overvejelser har I så haft før denne tilbygning eller renovering?
Hvis nej: Så forestil dig at i skulle renovere eller tilbygge eller forbedre indeklimaet, hvilke overvejelser
har I før denne tilbygning eller renovering?
Hvad er/har processen været – hvem gjorde hvad?:
Questions related to the VPC customer segment: pains
1. Hvilke udfordringer har i haft?
2. Var der nogen hindringer eller bekymringer? (Lovgivning, regler, økonomi)
3. Var der økonomiske overvejelser/begrænsninger? Hvilke – hvad måtte man prioritere/nedprioritere?
4. Hvad skal man bruge af oplysninger/viden - hvad manglede i?
Questions related to the VPC customer segment: gains
1. Hvad er formålet med en renovering eller med at forbedre indeklimaet: er det energi, bæredygtighed,
godt indeklima eller andet?
2. Havde i overblik over de økonomiske gevinster ved at renovere/forbedre indeklima?
Questions related to the VPC customer segment: general
1. Har i certificering eller har i overvejet det? (DGNB eller lign. – Hvorfor/hvorfor ikke)
(a) Hvis ja: udfordringer?
(b) Hvis nej: hvad skulle der til?
Questions related to the value proposition: product/service
1. Man regner med at lave en database for kontorbygninger i danmark, hvor man kan dele og
sammenligner erfaringer både med henblik på renovering og byggeri.
(a) Hvad tænker i umiddelbart ville være nødvendig i en sådan database?
(b) Er der nogle oplysninger, i kunne tænke jer at få adgang til før en renovering eller tilbygning?
118 INDOOR ENVIRONMENT IN A DIGITAL FUTURE

Questions = italic
APPENDIX E
Interview #1
Respondent answer related to value proposition canvas: ‘Job(s)’, ‘Pains’, ‘Gains’ and ‘Product’.
Navn: Niels Peter Frisesdal
Rolle: Daglig leder
Arbejdsområde: Sagsansvarlig inden for opgaver i byggeriet og alt hvad der er i jorden
Har I lavet nogen renovering, tilbygninger og ændringer de seneste år/eller prøvet at forbedre indeklimaet?
Ja, vi har prøvet at lave nogle tiltag. Først med solgardiner og så aircondition eller varmepumpe.
Hvilke overvejelser har I så haft før denne tilbygning eller renovering?
Jamen, vores problematikker var jo, at når vi havde vinduerne åbne for at skylle luften igennem så kom der
støv ind. Det var ubehageligt at sidde i, så vi måtte lave et lukket forum, som vi kunne være i.
Hvad er/har processen været – hvem gjorde hvad?:
Det foregår ved at inddrage dem inde i huset, dem der sidder i den pågældende del af kontoret. Så har de
lov til at komme med forslag og idéer til det. Så starter vi med at få solgardinet for, at se om det gav effekt. Og
det viste sig det var meget lidt, så havde vi sidenhen fat i et firma som havde med indeklima, eller aircondition
anlæg og nedkøling at gøre. Så drøftede vi med dem hvordan vi skulle gøre, hvordan vi fik luftstrømmene til at
cirkulere i rummet. Her er rimelig højt til loftet, så de foreslog det skulle sidde fra midten og ud mod væggene
i stedet for modsat. Derfor blev der sat to anlæg op.
Hvilke udfordringer har I haft? F.eks. at det er for varmt, folk klager osv.?
Vi har ind imellem godt vidst at det var for varmt, det er en mørk bygning og der er store vinduer i. Vi synes også
det var varmt og hedt at sidde i, på givne tidspunkter. Det er altid en udfordring om vi synes konstruktionen
og bygningsdesign skal ændres eller man kan lave det ved at lave luftskifte.
Så man ikke behøver laver en stor ombygning, men klarer det indefra?
Ja. En anden ting der har noget at gøre, det er de flader man har udadtil, hvor stærk isolerede de er, og hvor
meget varme de driver ind, men også hvor meget kulde de kan drive ind, f.eks. i vinduessamlinger og arealer
kan give begge dele.
Når I laver sådan noget om, har I så hindringer eller bekymringer f.eks. mht. lovgivning? Det kunne også være
luftskiftet – med henblik på træk eller lyset, bliver det for mørkt med gardinerne.
Nej det havde vi ikke. Men det var ellers et godt emne at vurdere hvordan lyset er. Vi har jo oplejret i kontoret.
Vi er her hyppigst kun i dagligdagen, men derfor er der jo stadig morgen og aften og sidst på dagen. Så lyset
det kan godt være det bliver det næste vi skal spekulere i, altså hvordan vi skal inddrage lyset i rummene. Men
lige præcis træk var en af de ting der var snak om, for at få luften til at cirkulere i rummet fra de anlæg der
skulle sættes om, så fordeling kom jævnt og blev drysset ned over medarbejderne i stedet for den blev blæst.
Det skulle det givne anlæg også, og det har vist sig det virker rigtig godt.
Har I været indover lovgivning, eller anbefalinger f.eks. anbefalinger til luftskifte?
INDOOR ENVIRONMENT IN A DIGITAL FUTURE 119

Nej, det har vi ikke haft myndighederne inddraget i, ej heller nogle af. . . hvad skal vi sige ingeniørfirmaerne. . .
vi har stolet blindt på aircondition firmaet.
Har økonomi spillet en rolle i disse beslutninger?
Som udgangspunkt har vi en holdning til, at det der som regel er bedst, er også lidt dyrere, men på længere
sigt er det altid det billigst. Det er i hvert fald vores erfaring. Køb noget godt og ordentligt, det holder længere,
og man bliver ikke ked af det og træt af det.
Var der økonomiske overvejelser/begrænsninger, som gjorde at noget måtte prioriteres fremfor noget andet,
eller noget blev nedprioriteret.
Altså nu har vi taget det over tid, det der med at prøve at få nogle mørklægningsgardiner ind, var jo det vi
prøvede det første år, og så fandt vi ud af det ikke var nok, og så var det først sæsonen efter. Det er sådan at
vores problematik er størst når det er sådan vi har virkelig sollys på, og det er jo i Danmark i princippet kun en
kortere periode, og derfor har vi lavet tiltagene over et par år.
Mht. støvet, fik vi ny belægning på ude foran, så vi samtidig med mørklægningsgardinerne kunne dæmpe
støvet, sådan vi bedre kunne have vinduerne åbne, men vi synes sikkert det var nok, og derfor valgte vi at få
køl på.
Hvad skal man bruge af oplysninger/viden - hvad manglede i?
Bygningen er jo fra 2008, og fra 2008 burde man måske have været klogere og inddraget det i bygningen på
det tidspunkt.
Kunne problemet have været løst nemmere, hvis I havde haft oplysninger eller erfaringer eller idéer til løsninger?
Vi har jo et tilstødende kontorlokale, som har en anden type aircondition, og derfra af erfaring kunne vi se, at
vi skulle passe meget meget på, hvordan man sidder med hensyn til træk.
Modsat er der en anden problematik, det er at vi byggede i 2008 og byggeriet gik ned og vi måske godt kunne
fornemme at problematikken var der med varme tidspunkter, og der var økonomien nok ikke med, og derfor
blev det nok tilsidesat i en periode, indtil man synes nu kunne vi ikke tilsidesætte det mere og økonomien blev
bedre.
Formålet med ændringen I lavet, var det hovedsagligt forbedring af indeklima, eller energimæssigt for bygningen,
eller bæredygtigt?
Formålet har hele tiden været det skulle være et rum som var rart at være i, men dermed ikke sagt at når
man sætter aircondition op som er en varmepumpe, så kunne man faktisk godt bruge den modsat, til at tage
varme om vinteren, og derved har vi tænkt energimæssigt over hvordan vi kan bruge den.
Havde I overblik over de økonomiske gevinster ved at renovere/forbedre indeklima?
Som udgangspunkt har vi ikke haft problemer med fravær og sygdomme og lignende hos medarbejdere,
men folks glæde ved at være i et sted der til at holde ud at være, kan man sagtens høre. Folk føler sig absolut
bedre tilpas i lokalet efter ændringerne.
Har I nogensinde overvejet at få certificeret jeres bygning? Det er jo blevet mere moderne at få certificeret
sin bygning især mhp bæredygtighed, fx svanemærket, DGNB
Nej, det har vi ikke.
Hvad skulle der til?
At nogen kan drage nytte af det. Man skal ikke gøre det bare for at gøre det. Det skal gerne være noget man
fælles kan få noget ud af.
Man regner med at lave en database for kontorbygninger i Danmark, hvor man kan dele og sammenligne
erfaringer både med henblik på renovering og byggeri, men også så man kan ” lære” af hinanden. Hvad
tænker i umiddelbart ville være nødvendig i en sådan database?
120 INDOOR ENVIRONMENT IN A DIGITAL FUTURE

Nogen steder man kan søge viden, eller rådgiver kan søge viden om hvordan tilstanden er og hvad vej man
bedst kan. Vi står jo selv både med en ældre bygningsdel vi skal have renoveret og nok have lavet bedre
indeklima i, men vi står også foran et nyt kontorafsnit som vi skal bygge indenfor en overskuelig fremtid. Så alt
viden der kan søges, kan kun være med til at bidrage positiv til fremadrettet renovering og indretning.
Er der nogle oplysninger, i kunne tænke jer at få adgang til før en renovering eller tilbygning?
Hvordan man gør noget mest enkelt og simpelt, for ting der er for teknisk, hvis mange skal håndtere det, så får
man aldrig det rigtige ud af det.
Har du andet? Det kan være orientering, vinduer osv.
Nu har vi tilfældigvis vinduer mod syd, og det er fordi vi skal have oversigt over vores areal den vej ud. Det giver
selvfølgelig udfordringer med vinduer mod syd, og alt hvad man kan drage nytte af, med problematikken med
vinduer mod syd ville selvfølgelig være at foretrække. Vinduer mod vest har selvfølgelig samme effekt, men
vinduer mod syd står solen nok at bager mest og længst tid i løbet af dagen. Men også for den sags skyld lyset
for nord af, som man ikke er generet af, altså man får rummene rigtig placeret, og man drager nytte af det
nordlige lys og man drager nytte af solen for syd, og altså erfaringer fra hvordan man placerer rummene og
hvordan man sidder, som den almene opbygning af et kontor er jo også vigtig. Det er jo ikke kun spørgsmål om
man bare får suget og blæst og styret temperaturen, og får nogle filtre på så det ikke støver, og får skærme op
så det ikke larmer, men bare den helt lavpraktiske simple indretning, hvordan man kan gøre noget lettest, så
der ikke skal være en masse tilvalg bagefter for at redde bygningen. Hvis man har en database eller eferinger
indenfor det, så starter man jo ikke fra nul hver gang man skal til at indrette.
INDOOR ENVIRONMENT IN A DIGITAL FUTURE 121

Questions = italic
APPENDIX F
Interview #2
Respondent answer related to value proposition canvas: ‘Job(s)’, ‘Pains’, ‘Gains’ and ‘Product’.
Navn: Jesper Dyhr
Rolle: Produktionschef
Arbejdsområde: Overordnet ansvarlig for produktion at betonelementer
Har I lavet nogle renovering, tilbygninger og ændringer de seneste år hvor i har forsøgt at forbedre
indeklimaet?
Ja altså derude hvor i foretog målingerne – og det er jo sjovt at man sætter en ” skurby” op og
pakker ind i plader når man nu selv laver betonelementer, men det var den nemmeste løsning på
det tidspunkt. Så ja det har vi, vi har også bygget ovre i Søndersø.
Okay lad os tage Pavillonen som eksempel (der hvor vi foretog målingerne), hvordan er processen
når i går i gang med sådan en udvidelse af jeres kontor – altså fra i finder ud af at der er noget i
gerne vil have løst – til i går i gang med at bygge bygningen?:
Det aller første skridt i vores verden, det er at CRH jo er en koncern der på verdensplan har et sted
mellem 85.000 og 100.000 medarbejdere fordelt på cirka 40 lande, så hver gang vi skal foretage os et
eller andet i den sammenhæng, så skal vi ansøge ud i det store udland om nogle penge og midler,
og det er i store koncerner. . . i store koncerner er ikke-afkastgivende investeringer ikke altid dem der
bliver prioriteret højest. Hvis vi nu ville bygge en ny hal hvor vi kunne producere og tjene 10 millioner
ekstra om året, så ville vi have fuld opmærksomhed – men når vi bare siger at vi skal have mere eller
bedre plads til vores medarbejdere, hvilket jo selvfølgelig også er en del af at tjene de 10 millioner,
så er det knapt så nemt. Og grunden til at den ikke er bygget i vores egne elementer, det er ren
og skær økonomi. Det var kun fordi at det her kunne gøres billigere, og når ikke behovet var der
længere, så piller vi skidtet ned igen. Så økonomi har en enorm betydning – det har det alle steder,
det er ikke kun i vores.
Hvilke udfordringer, hindringer eller bekymringer har I haft inden i begynder at bygge det her, som
du selv har nævnt, kan det være økonomi, men det kunne også være i forhold til andre ting?
Ja det er jo altid udgangspunktet, altså det må ikke koste noget, men det skal helst ligne og være
en million.
Har der været andre hindringer eller bekymringer, f.eks. lovgivning, regler eller andet end det økonomiske?
Ja, ikke måske bekymringer, men i hvert fald overvejelser, der er jo også, på trods af at det kun
er to niveauer, rampe og elevator og alverdens ting og sager – selvom jeg ikke tror elevatoren nogensinde
har kørt, ud over den ene gang om året hvor den bliver tjekket. De der ting der nu skal
være, handikapvenlighed mm. – der er mange ting der skal tænkes ind i et byggeri.
Hvad har der været af økonomiske overvejeler eller begrænsninger der betød at i måtte prioritere
eller nedprioritere i forhold til indeklima eller andet?
Der er klart nedprioriteret. Sådan starter man jo altid. Det er ligesom når man finder en bil, så finder
man altid den største og den bedste først, og så kigger man på hvad den koster, og så finder man
den man har råd til bagefter.
122 INDOOR ENVIRONMENT IN A DIGITAL FUTURE

Har i haft nogle oplysninger eller viden, som i har manglet eller haft brug for som havde været fint at
få i starten, men man måske først har fundet ud af bagefter?
Nej, ikke mig bekendt, men vi er jo også relativt godt inde i byggereglementet eftersom vi selv er i
byggebranchen – så der er ikke som sådan så meget der overrasker os.
Hvad var formålet med jeres tilbygning?
Det var ren og skær pladsmangel.
Hvad har i noget overblik over de økonomiske gevinster i har fået ved at bygge til?
Nej, det har vi ikke lavet noget regnestykke over. I bund og grund har det jo givet os arbejdspladser
nok, og det gør jo at vi har kunnet huse de medarbejdere vi har skullet have for at sikre gennemførslen
af vores produktion – som jo i sidste ende er den vi lever af. Men der er selvfølgelig en masse andre
ting før som vi også skal have med, så hvis vi ikke havde haft det, så skulle vi have været ude i byen
og købe det hos tegnestuer og betale overpris for det, men der er ikke lavet et regnestykke på det.
Har i overvejet at få certificeret jeres bygninger eller planlagte bygninger? F.eks. DGNB. Er det noget
i har haft tænkt over?
Nej er det korte svar, men hvis vi skulle bygge en hel ny fabrik, så ville vi selvfølgelig tænke over det,
for det er jo det eneste rigtige lige i øjeblikket, og der er jo en masse krav i den sammenhæng som
vi skal leve op til over for vores kunder, så det vil jo også være det rigtige at gøre selv. Og vi har en
del tiltag her i koncernen med genbrug af vand og lignende net op for at få et bedre regnestykke
på den konto. Der er klart et grønt fokus, men altid med økonomi lige ved siden af.
Hvis man skulle lave en database for kontorbyggerier i Danmark hvor man kan dele erfaringer og
sammenligne, både med henblik på renovering, men også med henblik på byggeri. Hvad har du
så af tanker omkring det – hvis du skal tænke på hvad der især kunnet være vigtigt at dele? Det
kunne være alt fra orientering af bygning, vinduer, solafskærmning, materialer.
Jeg synes ikke at jeg har så meget at dele. Det vi har bygget herude, blev holdt på et minimum, så
jeg tror ikke at jeg har noget at dele med hele verden på den konto.
Er der nogle oplysninger i kunne tænke jer at have adgang til før man vælger at lave en renovering
eller en tilbygning?
Jeg er usikker på om det er der vi ville søge vores oplysning, men hvis databasen er god nok, og den
bliver synliggjort nok, så vil det selvfølgelig være et sted man kigger. Man skal vi vide at det er der for
at lede. Altså man tror jo at det nemmeste i hele verden det er jo at gå på google og så har man
svarret på alt, og det har jeg så konstateret et par gange, at det har man ikke. I hvert fald ikke på
den måde jeg evner at søge på, på det jeg skal bruge lige i øjeblikket. Så synlighed er jo ekstremt
vigtigt – oplysning: ” det er her i finder det rigtige” .
INDOOR ENVIRONMENT IN A DIGITAL FUTURE 123

APPENDIX G
IEQ Investigation
TVOC box plot comparison of 24h and total measurements
Noise box plot comparison of 24h and total measurements
124 INDOOR ENVIRONMENT IN A DIGITAL FUTURE

APPENDIX H
Parameter Weighing
Acoustics
Objective 50%
SPL 50%
Subjective 50%
Symptoms 25%
Noisy 25%
Acoustic comfort weighting
IAQ
Objective 60%
CO2 35%
Particulate Matter 10%
VOC 10%
OP 5%
Subjective 40%
Odurs 20%
Symptoms 20%
IAQ weighting
Visual
Objective 50%
Light 25%
Daylight 20%
Correlated Light Colour 5%
Subjective 50%
Symptoms 15%
Lighting to dim 7,5%
Lighting to bright 7,5%
Glare 5%
User control 15%
Visual comfort weighting
Thermal comfort
RH 30%
Measurements 15%
Dry air 5%
Humid 5%
Symptoms 5%
Temperature 60%
Measurements 40%
To cold 5,0%
To hot 5,0%
Symptoms 10%
Other 10%
To much air movement 5%
To little air movement 5%
Thermal comfort weighting
INDOOR ENVIRONMENT IN A DIGITAL FUTURE 125

APPENDIX I
Economic calculations
Equations for finding productivity percentages
126 INDOOR ENVIRONMENT IN A DIGITAL FUTURE

Economic calculations for Expan
INDOOR ENVIRONMENT IN A DIGITAL FUTURE 127

Economic calculations for Expan
128 INDOOR ENVIRONMENT IN A DIGITAL FUTURE

APPENDIX J
IEQ Reports
INDOOR ENVIRONMENT IN A DIGITAL FUTURE 129