DRAFT CONCEPT DESIGN REPORT UNIVERSITY OF CALGARY ...

8.2 Sustainability ( Reference Appendix D )
� OVERVIEW
The project is pursuing LEED ® NC-Canada certification; as such, the building is
required to meet Energy and Atmosphere (EA) Prerequisite 2: Minimum Energy
Performance and are striving to achieve points for EA Credit 1 Optimize Energy
Performance. The selected compliance path for both objectives is ASHRAE 90.1-
2007 and the associated Energy Cost Budget methodology.
For this purpose an energy model was developed in order to assess the buildings
predicted energy consumption per the Building Energy Cost Budget Method in
chapter 11 of the reference standard.
A double façade was explored for the tower; extending from the 7 th to the top floor.
This feature reduces solar heat gains in the summer while retaining envelope heat
losses and acting as a “greenhouse” to passively heat the building and preheat
incoming building air in the winter. Three models were developed to explore this
option fully; a model with the double façade located on the southern orientation, one
with the double façade located on the eastern orientation, and one model with no
double façade. It was found that the double façade located on the eastern
orientation contributed the greatest energy savings and therefore all results
described in the following sections refer to this model.
The model demonstrates that as currently designed, the MacKimmie Complex
achieves the ASHRAE 90.1 minimum requirements per the Energy Cost Budget
Method, and further demonstrates a 45% decrease in regulated annual modelled
energy costs. The current version of LEED asks for the building to demonstrate a
reduction in energy cost compared to the energy cost of the ASHRAE 90.1-1999
standard. While it is recognised that ASHRAE 90.1-2007 is more stringent than the
1999 standard, by using the 2007 standard it better aligns with the University
guidelines and gives a more conservative points estimate. The proposed design
meets EA Pr. 2 and is eligible for up to seven (7) EA Credit 1 points.
The simulations and the design are preliminary in nature; the accuracy of the
simulations reflects this and are typically considered to be within ±10% of the final
design. Therefore, at least two projected LEED Energy and Atmosphere Credit 1
energy points as reported in this document should be deducted from each building’s
initial LEED scorecard and deemed a “maybe” until such time as a final compliance
simulation is completed. Two EA Credit 1 points should be deemed as “maybes” for
Mackimmie and five (5) points should be deemed achievable.
� ENERGY MODEL
Energy analysis and simulation can be used to estimate the energy consumption of
a building based on the local climate characteristics, system choices, and geometry.
The purpose of this energy simulation was to confirm the building will meet the
energy requirements of the LEED Canada-NC rating system.
Simulation tools bring architectural and engineering design aspects together to
predict how different building components will interact with each other and the
environment. By understanding the relationship between individual building
components and the building as a whole, the model can estimate the energy use of
the proposed building.
� ENERGY ANALYSIS GOALS
Baseline/Proposed Building
An energy model was developed to represent the current buildings’ proposed
design. Using this energy model, each building was characterised by:
Electricity Consumption and Demand
Natural Gas Consumption
Total Energy Cost
Process related equipment is not covered under the applicable reference standard
or LEED and was therefore excluded from the simulation. However, approximations
for plug loads were made to ensure Heating Ventilation and Air Conditioning
(HVAC) system loads were accurately simulated.
ASHRAE (Code) Building
The proposed building was analysed for ASHRAE compliance by following the
Building Energy Cost Budget Method. This involved creating a separate energy
model with the same building layout, and by altering the performance parameters of
glazing, envelope, mechanical and electrical (lighting) systems to the minimum
values permitted by the code. The annual predictive energy cost estimate of this
simulation was compared to the results of the baseline building design simulation to
ascertain whether the annual regulated energy cost of the proposed building was
45% less than the code reference, thereby meeting the minimum energy
requirements of LEED Canada-NC version 1.0.
Conclusions
The models demonstrated that as currently designed the MacKimmie Building
achieves the ASHRAE 90.1 minimum requirements per the Energy Cost Budget
Method, and further demonstrate a 45% decrease in regulated annual modelled
energy costs; therefore the proposed design meets LEED Energy and Atmosphere
(EA) Prerequisite 2 and is eligible for up to seven (7) EA Credit 1 points.
It should be noted that the simulations and the design are preliminary in nature; the
accuracy of the simulations is typically considered to be within ±10% of the final
design and therefore at least two (2) LEED EA Credit 1 energy point as reported in
this document should be deducted from each building’s initial LEED scorecard and
deemed a “maybe” until such time as a final compliance simulation is completed.
Two EA Credit 1 points should be deemed as “maybes” for Mackimmie and five (5)
points should be deemed achievable.
CONCEPT DESIGN REPORT
UNIVERSITY OF CALGARY
MacKimmie Tower and Block I Repurposing and Renewal
Table 3: Annual Breakdown of Energy Use – Proposed Mackimmie vs.
ASHRAE & Existing (see Appendix D)
Proposed
ASHRAE
Existing
Energy Costs
$450,000
$400,000
$350,000
$300,000
$250,000
$200,000
$150,000
$100,000
$50,000
$0
Annual Elec
Consumption
(kWh)
Annual Heating
Consumption (GJ)
Energy Cost per Year
1,693,000 1,886 $ 174,292
2,809,000 7,981 $ 315,044
1,387,993 34,963 $ 391,563
Energy Cost Comparison
Current Utility Data Proposed Building ASHRAE 90.1 2007
0%
6%
MacKimmie Design Energy End-Use
4% 8%
9%
40%
15%
18%
8. CONCEPT DESIGN
Lighting
Equipment
Heating
Cooling
Heat Reject
Pumps & Aux
Fans
DHW
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