Technologies…

w3.bwk.tue.nl

Technologies…

Local climatization,

personal ventilation,

and other new comfort

technologies…

Edward Arens

UC Berkeley

ISIAQ, TU Eindhoven April 8, 2010


Background

• Our previous local comfort tests

found that:

In cool conditions, feet and hands

dictate overall discomfort

In warm conditions, head and hands

dictate overall discomfort

• This suggested a personal

environmental control system

(PECS) that focuses directly on

these body parts.

Eindhoven April 8, 2010


Presentation

We did two sequential laboratory tests of a new system

• Description of system components

• Thermal comfort test results

• Perceived air quality (PAQ) results

• Body plume effect on PAQ

• Comfort when away from PEC

• Energy efficiency

Eindhoven April 8, 2010


Environmental chamber with PECS

Eindhoven April 8, 2010


PEC system components

Cold conditions

Warm conditions

Palm warmer

Heated keyboard

Head cooling device

Foot warmer

Hand cooling device

Eindhoven April 8, 2010


PEC warming effect in cool environments

Heated keyboard with a palm warmer

Foot warmer

Before applying

After applying

Before applying After applying

Eindhoven April 8, 2010


PEC cooling effect in warm environment

Head and hand cooling devices

Before applying

After applying

Eindhoven April 8, 2010


The air movement system

Opposed nozzles supplied by two 4W fans provide a radial outflow in

the breathing zone

4W muffin fan

2 inch nozzle

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Flow characterization at

Syracuse University

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10 0

2’’ nozzle

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4’’ nozzle

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Eindhoven April 8, 2010


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0.001 0.110 0.219 0.328 0.437 0.546 0.655 0.764 0.873 0.982 1.091 1.200 1.309 1.418 1.527 1.636 1.745 1.854 1.963 2.072

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0.001 0.110 0.219 0.328 0.437 0.546 0.655 0.764 0.873 0.982 1.091 1.200 1.309 1.418 1.527 1.636 1.745 1.854 1.963 2.072

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Map of radial outflow

Eindhoven April 8, 2010


User control for the tests

Eindhoven April 8, 2010


Plan for the first test

• 9 male and 9 female college students

• 5 three-hour tests/person, 90 tests total

• 3 uses of PECS in random order:

1. No PECS

2. Fixed PECS

3. User controlled PECS

Room air temperature (ºC) Jet air temperature (ºC)

Hot 30 24

Warm 28 28

Neutral 25 25

Cold 20 no

Very cold 18 no

Eindhoven April 8, 2010


Test procedure

Alternating sequence of one-hour sessions

(Arrows indicate times when surveys are administered. Each survey addresses

thermal comfort, perceived air quality, air movement, and dry-eye discomfort

No PEC (60 min)

No user control

Fixed PEC Occupant (60 min) no control Variable PEC (60 Occupant min) control

No user control

User control

Eindhoven April 8, 2010


Subjective surveys

• Overall and local thermal sensation

• Overall and local thermal comfort

• Perceived air quality

Eindhoven April 8, 2010


Results: thermal sensation

Very hot

4

3

2

(P


Results: comfort

Very comfortable

4

3

Just comfortable

Just uncomfortable

2

1

0

-1

(P


Impact of air movement on perceived air quality

PECS

PECS

PECS uses heating

PECS uses air movement

Eindhoven April 8, 2010


Impact of air movement on perceived air quality

Eindhoven April 8, 2010


Chamber set up for second test

• Always 28ºC, 50%RH

• Room air from nozzles

Eindhoven April 8, 2010


Test conditions

• 9 male and 9 female college students

• four 3.5-hour and one 1.5-hour tests/person, 90 tests total

• facial velocities: 0, 0.6, 1.0 m/s

• nozzle diameters: 2”, 4”

• number of nozzles: 1, 2

• plume effect: no collar, collar, 0.6 m/s airspeed

Eindhoven April 8, 2010


Comfort with various nozzle/speed configurations

Eindhoven April 8, 2010


Perceived air quality for same configurations

Eindhoven April 8, 2010


Impact of air movement on perceived air quality

Eindhoven April 8, 2010


Comfort when away from PEC

Two questions

• How comfortable are people at

28ºC when away from the PEC

• How quickly is comfort restored

by the PEC

Two scenarios

• 10 minute break between tests

(representing visits to copy

machines or bathrooms)

• 15 minute break with two sets of

40 steps (equivalent to a round

trip up and down 5 stories)

Eindhoven April 8, 2010


Comfort during and after 10 minute break

Eindhoven April 8, 2010


Comfort after the 2 x 40 step exercise

Eindhoven April 8, 2010


Investigating the reasons for PAQ improvement

Without a collar

With a collar

Collar can deflect the plume effectively

Eindhoven April 8, 2010


Creating body odor; isolating body plume

Eindhoven April 8, 2010


Body odor intensity and PAQ

Body odor intensity, no differences: ‐2.1, ‐2.2, ‐2.2

Eindhoven April 8, 2010


If insufficient body odor; add scent

Eindhoven April 8, 2010


Scent intensity: plume has an effect

5 min 5 min

Eindhoven April 8, 2010


Conclusion

• PECS is effective at providing comfort

• Air movement in facial region is effective at:

• improving PAQ

• reducing inhalation of the body’s plume

• (perhaps) improving real air quality when there are ozone

reactions occurring in the body plume.

• Now the focus is:

• Designing energy efficient PECS

• Devising practical configurations within interior spaces

Eindhoven April 8, 2010


Energy efficiency is the key - Low energy fan

3 W!

1 m/s

corresponds to 3K

temperature

increase

occupancy sensor

remote control

Eindhoven April 8, 2010


Eindhoven April 8, 2010


Eindhoven April 8, 2010


Eindhoven April 8, 2010


TouchDesk

Eindhoven April 8, 2010


Expanding the interior temperature range

• Substantial

energy savings

in HVAC

• May enable

switch to more

efficient

cooling

systems

Percent Savings

50

45

40

35

30

25

20

15

10

5

0

16 18 20 22 24 26 28 30

Setpoint (ºC)

Phoenix Minneapolis San Francisco Miami

(71F to 75F)

Hoyt, T., H.L. Kwang, H. Zhang, E. Arens, T. Webster, 2009, “Energy savings

from extended air temperature setpoints and reductions in room air mixing.”

International Conference on Environmental Ergonomics 2009

Eindhoven April 8, 2010

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