Assessment of Indoor Climate: Outdoor climate Learning ... · Assessment of Indoor Climate: Learning from Buildings ... Indicator Roomvent 2007, Helsinki ... Effect of temperature

Roomvent 2007: 10th International Conference on Air Distribution in Rooms

Helsinki, June 13-15, 2007

Center for the Built Environment (CBE) http://www.cbe.berkeley.edu Page 1

Roomvent 2007, Helsinki

Edward ArensCenter for the Built Environment

UC Berkeley

Assessment of Indoor Climate:Learning from Buildings


Outdoor climate


Indoor climate


Energy Use

Buildings

36%

Industry

37%

Transportation

27%

Buildings use 68%of electricity

Most building energy goes to conditioning the indoor environment


Helping solve the energy problem

Need a major creative effort by everyone involved

to design and operateefficient and acceptable

indoor environments

Assessment of indoor climate (feedback) is key

• Buildings (and their systems)• People (building occupants and operators)


Assessing indoor climate

Managing their environmental control costsOccupants

Employees’ satisfaction and productivityEmployers

Feedback during HVAC system calibrationCommissioning agents

Operating setpoints; diagnosing failures and complaints

Bldg operators

Evaluating quality of buildings and their maintenance staff

Bldg owners

Obtaining feedback about designs and use of technology

Designers

Developing standards; design guidanceResearchers





Assessment techniques

1. Mobile comfort carts2. Stationary indoor climate monitor 3. Commissioning cart with wireless sensor array4. Homeowners’ energy information system5. ‘Right-now’ surveys6. Comfort polling station7. Web-based indoor environmental quality survey

These appear in example research projects


Example 1: research on thermal comfort

ASHRAE research on operating buildings in 1980’s and 90’s

• Was Standard 55 being followed in real buildings?

• Were the criteria correct?

Involved detailed measurement of physical environment and occupant responses

160 bldgs


Thermal comfort assessment carts

Mark 1

Mark 2


“Right now” occupant survey – scales


Analyzing the ASHRAE comfort database:

Centrally-controlled HVAC bldgs Naturally ventilated buildings

Predicted: Lab-based PMV modelObserved: Field-based adaptive model

2021222324252627

-5 0 5 10 15 20 25 30 35outdoor temperature index, ET* (oC)

indoo

r com

fort t

emp’

Top (

o C)

2021222324252627

-5 0 5 10 15 20 25 30 35indoo

r com

fort t

emp’

Top (

o C)

outdoor temperature index, ET* (oC)

deDear and Brager used these data to develop the Adaptive Comfort Model, now in Std. 55, for operable windows


Example 2: Commissioning cart project

The commissioning cart was inspired and funded by the New York Times

• One of three specialized carts for commissioning new building systems in their headquarters

• Lighting• Shades• Underfloor thermal and

ventilation system





Commissioning for thermal stratification

0

1

2

3

4

5

6

7

8

9

10

11

69 70 71 72 73 74 75 76 77 78 79 80 81 82

Room Temperature, °F

Hei

ght,

ft

1.0 cfm/sq. ft0.6 cfm/sq. ft0.3 cfm/sq. ft

5°F ∆TASHRAE Std.55-2004

Still satisfies vertical temperature difference (5°F) with 40% less air


Commissioning cart

Temperature profiling up to 5 meters

Telescoping stratification measurement tree

Data acquisition boards

Lanyard for raising tree

12 VDC Battery power system

Cart laptop computer

Pressure sensor, with plastic tubing tether (with internal thermocouple)


Cart display screens

200 artificial loads70 motes


Examples 3 & 4: assessment for ‘demand response’

Electrical demand shedding and shifting (precooling):3. residential4. commercial

Cal ISO Daily Peak LoadsJanuary 1, 2000 - December 31, 2000

20

25

30

35

40

45

50

Jan-00

Feb-00

Mar-00

Apr-00

May-00

Jun-00

Jul-0

0

Aug-00

Sep-00

Oct-00

Nov-00

Dec-00

GW

Peak Day August 16 - 43.5 GW

Commercial AC

Residential AC

10 GW!!


Demand-responseelectrical appliance manager

Real-time Meter

Utility

Price

Elec

tricit

y use

d

Occupancy sensors

Power sensor

Temperature sensors

Power actuators

Price Indicator


Adjust position

Start/stop on/off

Provide information

Reset setpoint

Suggest action

Shading

Window

Blinds

AC

Vent

Refriger

Computer

Office devices

Lights

Thermal comfort

Temperature, radiation, air velocity, humidity, preference

Occupancy

Motion, sound, CO2, schedule

Envelope

Window position, blind position, air velocity

HVAC

Temperature, humidity, pressure, air velocity

Lighting

IlluminationGlare

Energy and Power

Voltage, current, power factor, fuel flow, price

•Informing occupants;

•Manual actuation

•Automatic actuation

New integrated building control system

Expanded user interface for input, data output, advice

Ambient intelligence





Automated thermal comfort polling stations

Studies of transient occupanciesLogs simultaneous physical measurements

Polling station in a bankRoomvent 2007, Helsinki

Example 5: CBE Indoor Environmental Quality survey

Data from• 320 buildings• 47,000+ occupants• 31 green buildings

For building evaluation and problem diagnosisOther uses


Indoor Environmental Quality survey• Web-based, consistent questions over time• Automatic reporting tool


Spatial LayoutSpatial Layout

Office FurnishingsOffice Furnishings

Thermal ComfortThermal Comfort

Air QualityAir Quality

LightingLighting

AcousticsAcoustics

Clean/MaintClean/MaintGeneral

CommentsGeneral

Comments

LocationLocation

BackgroundBackground

IEQ survey categories


Drill-down questions

Satisfaction Scale

Next survey topic

Branched to a follow-up page with questions regarding nature and cause of dissatisfaction


Thermal branching page: causes of complaints





IEQ Survey results


14%13%15%

19%16%16%

6%

-

2,000

4,000

6,000

8,000

10,000

-3 -2 -1 0 1 2 3

Num

ber o

f res

pson

ses

very dissatisfied very satisfied

Thermal satisfaction: 2nd lowest category

“How satisfied are you with the temperature in your workspace?”

Overall: 58% of respondents satisfied


14%15%

24%21%

15%

9%

1% 1%

0102030405060

0-9%

10-1

9%20

-29%

30-3

9%40

-49%

50-5

0%60

-69%

70-7

9%80

-89%

90-9

9%10

0%

Percent satisfied

Num

ber o

f bui

ldin

gsx

Distribution of thermal satisfaction

Percent satisfied: Top 4 points (>=0) on 7-point satisfaction scale

11% of buildings meet acceptability standard


9% 10%13%

23%

18%19%

8%

-

2,000

4,000

6,000

8,000

10,000

-3 -2 -1 0 1 2 3

Num

ber o

f res

pson

ses

very dissatisfied very satisfied

Air quality satisfaction: 3rd lowest category“How satisfied are you with the air quality in your workspace (i.e. stuffy/stale air, cleanliness, odors)?”

Overall: 68% of respondents satisfied


1%

8%

19%20%

25%

15%

9%

2%1%

0102030405060

0-9%

10-1

9%20

-29%

30-3

9%40

-49%

50-5

0%60

-69%

70-7

9%80

-89%

90-9

9%10

0%

Percent satisfied

Num

ber o

f bui

ldin

gsx

Distribution of air quality satisfaction

Percent satisfied: Top 4 points (≥0) on 7-point satisfaction scale

26% of buildings meet acceptability standard


Thermal satisfaction, by building type

Mean Scores - Thermal ComfortLEED (n=31) compared to CBE database (n=257)

-3

0

3

0% 25% 50% 75% 100%

Percentile Rank

Mea

n Sa

tisfa

ctio

n Sc

ore

leed median: 0.42db median: -0.13

mixed mode median: 0.62

LEED (n=31), mixed mode (n=5) compared to CBE database (n=257)

Data for evolving green building design criteria





Air quality satisfaction, by building type

Mean Scores - Air QualityLEED (n=31) com pared to CBE database (n=257)

-3

0

3

0% 25% 50% 75% 100%

Percentile Rank

Mea

n Sa

tisfa

ctio

n Sc

ore

leed m edian: 1.21

db m edian: 0.21

mixed mode median: 1.95

LEED (n=31), mixed mode (n=5) compared to CBE database (n=257)


Green buildings and acoustic satisfaction

Mean Scores - Acoustic QualityLEED (n=31) compared to CBE database (n=257)

-3

0

3

0% 25% 50% 75% 100%

Percentile Rank

Mea

n Sa

tisfa

ctio

n Sc

ore

leed median: -0.15db median: -0.25


An office building in Virginia:

Overall Building: High (+)

Workplace: Low (-)

Lighting: Very High (++)

Air Quality: Very High (++)

Thermal Comfort: Low (-)

Acoustics: Very Low (--)

Response Rate: 69%

‘Green Building Confessions’…

* (Compared to the CBE database of projects)


Air Quality• Higher satisfaction than

average for all CBE surveys

Thermal Comfort• Significant variation among

buildings• Low cost-driven design

decisions = low satisfaction rate

• Limited controls impacts satisfaction

Green Building Confessions…

Overall Satisfaction - Air QualityHOK Buildings Compared to CBE Database

-3

0

3

0% 25% 50% 75% 100%

Percentile Rank

Mea

n Sa

tisfa

ctio

n Sc

ore

Overall Satisfaction - Thermal ComfortHOK Buildings Compared to CBE Database

-3

0

3

0% 25% 50% 75% 100%Percentile Rank

Mea

n Sa

tisfa

ctio

n Sc

ore


Example 6: Field study research on air movement


Window-ventilated open-plan office building

CBE IEQ survey for background• two seasons• ~100 occupants/season (half of the

building population)

Repeated “right now” survey• two week test period each season• 38 occupants/season• Total more than 2000 surveys

Ambient measurements• air and globe temperatures, humidity,

and air velocity at 38 workstations• Continuously during both seasons





Desktop indoor climate monitor (ICM)

Anemometer(air speed)

Shielded Dry Bulb Globe

Temperature

Monitoring station and voting box units, Fishman and Pimbert, 1978


ICMs

ICM application will be described later..


“Right now” survey – air movement questions


“Right now” survey:air movement preference question

Many more people wanted more air movement than less

Summer, N = 1040 Winter, N = 1028

want more 45% (n=468)

want less 3% (n=31)

no change 52% (n=540)

want more 28% (n=288)

want less 4% (n=41)

no change 68% (n=699)


Thermal sensation and air movement preference


10% of the measured velocity > 0.2 m/s, N=194

Higher velocities--above the 0.2 m/s draft limit





Air movement preferences > 0.2 m/s

want more 50%

no change 45%

want less 5%

unacceptable air motion (45%)

acceptable air motion (55%)

want more 71%no change 23%want less 6%


Effect of temperature on perceived air quality

Overall Satisfaction - Air QualityBCC Compared to CBE Database

-3

0

3

0% 25% 50% 75% 100%

Percentile Rank

Mea

n S

atis

fact

ion

Sco

re

summer

winter

Overall Satisfaction - Air QualityBCC Compared to CBE Database

-3

0

3

0% 25% 50% 75% 100%

Percentile Rank

Mea

n S

atis

fact

ion

Sco

re

summer

winter

Summer average indoor temperature 24.2ºC, average thermal sensation 0.4

Winter average indoor temperature 22.8ºC, average thermal sensation 0.1


Conclusion: future roles for assessment

More surveying of occupant satisfaction (web)More simultaneous measurement of physical environment and occupant responses.

• With developments in wireless, this is becoming easier to do• Use for building operation as well as research

Examine standards and standard practice• Humidity limits need detailed assessment in buildings:

cause/effect links for perceived air quality, and health

Control systems with ‘ambient intelligence’ – humans as informed and adaptive actuators

Documents

Assessment of Indoor Climate: Outdoor climate Learning ... · Assessment of Indoor Climate: Learning from Buildings ... Indicator Roomvent 2007, Helsinki ... Effect of temperature