Roomvent 27: 1 th International Conference on Helsinki, June 1-15, 27 Assessment of Indoor Climate: Learning from Buildings Outdoor climate Edward Arens Center for the Built Environment UC Berkeley Indoor climate Energy Use Industry 7% Buildings 6% 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 operate efficient and acceptable indoor environments Assessment of indoor climate (feedback) is key Buildings (and their systems) People (building occupants and operators) Assessing indoor climate Researchers Designers Bldg owners Bldg operators Commissioning agents Employers Occupants Developing standards; design guidance Obtaining feedback about designs and use of technology Evaluating quality of buildings and their maintenance staff Operating setpoints; diagnosing failures and complaints Feedback during HVAC system calibration Employees satisfaction and productivity Managing their environmental control costs Center for the Built Environment (CBE) http://www.cbe.berkeley.edu Page 1
Roomvent 27: 1 th International Conference on Helsinki, June 1-15, 27 Assessment techniques 1. Mobile comfort carts 2. Stationary indoor climate monitor. Commissioning cart with wireless sensor array 4. Homeowners energy information system 5. Right-now surveys 6. Comfort polling station 7. Web-based indoor environmental quality survey These appear in example research projects Example 1: research on thermal comfort ASHRAE research on operating buildings in 198 s and 9 s Was Standard 55 being followed in real buildings? Were the criteria correct? Involved detailed measurement of physical environment and occupant responses 16 bldgs Thermal comfort assessment carts Right now occupant survey scales Mark 1 Mark 2 Analyzing the ASHRAE comfort database: Example 2: Commissioning cart project Centrally-controlled HVAC bldgs Naturally ventilated buildings indoor comfort temp Top ( o C) 27 26 25 24 2 22 21 2-5 5 1 15 2 25 5 outdoor temperature index, ET* (oc) Predicted: Lab-based PMV model Observed: Field-based adaptive model indoor comfort temp Top ( o C) 27 26 25 24 2 22 21 2-5 5 1 15 2 25 5 outdoor temperature index, ET* (oc) dedear and Brager used these data to develop the Adaptive Comfort Model, now in Std. 55, for operable windows 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 Center for the Built Environment (CBE) http://www.cbe.berkeley.edu Page 2
Roomvent 27: 1 th International Conference on Helsinki, June 1-15, 27 Commissioning for thermal stratification Commissioning cart Height, ft 11 1 9 8 7 6 5 4 2 1 1. cfm/sq. ft.6 cfm/sq. ft. cfm/sq. ft ASHRAE Std.55-24 5 F T 69 7 71 72 7 74 75 76 77 78 79 8 81 82 Room Temperature, F Still satisfies vertical temperature difference (5 F) with 4% less air Temperature profiling up to 5 meters Telescoping stratification measurement tree Cart laptop computer Lanyard for raising tree Data acquisition boards 12 VDC Battery power system Pressure sensor, with plastic tubing tether (with internal thermocouple) Cart display screens Examples & 4: assessment for demand response Electrical demand shedding and shifting (precooling):. residential Cal ISO Daily Peak Loads January 1, 2 - December 1, 2 4. commercial 5 45 4 Peak Day August 16-4.5 GW Commercial AC 1 GW!! GW 5 25 Residential AC 2 2 artificial loads 7 motes Jan- Feb- Mar- Apr- May- Jun- Jul- Aug- Sep- Oct- Nov- Dec- Demand-response electrical appliance manager Thermal comfort Temperature, radiation, air velocity, humidity, preference Ambient intelligence Power actuators Price Indicator Temperature sensors Price Utility Power sensor Realtime Meter Electricity used Occupancy Motion, sound, CO 2, schedule Envelope Window position, blind position, air velocity Lighting Illumination Glare New integrated building control system Expanded user interface for input, data output, advice Provide information Suggest action Informing occupants; Manual actuation Automatic actuation Shading Window Blinds AC Vent HVAC Adjust position Refriger Occupancy sensors Temperature, humidity, pressure, air velocity Energy and Power Voltage, current, power factor, fuel flow, price Start/stop on/off Reset setpoint Lights Computer Office devices Center for the Built Environment (CBE) http://www.cbe.berkeley.edu Page
Roomvent 27: 1 th International Conference on Helsinki, June 1-15, 27 Automated thermal comfort polling stations Studies of transient occupancies Logs simultaneous physical measurements Example 5: CBE Indoor Environmental Quality survey Data from 2 buildings 47,+ occupants 1 green buildings For building evaluation and problem diagnosis Other uses Polling station in a bank Indoor Environmental Quality survey IEQ survey categories Web-based, consistent questions over time Automatic reporting tool Background Location Spatial Layout Office Furnishings Thermal Comfort Air Air Quality Lighting Acoustics Clean/Maint General Comments Drill-down questions Thermal branching page: causes of complaints Satisfaction Scale Next survey topic Branched to a follow-up page with questions regarding nature and cause of dissatisfaction Center for the Built Environment (CBE) http://www.cbe.berkeley.edu Page 4
Roomvent 27: 1 th International Conference on Helsinki, June 1-15, 27 IEQ Survey results Thermal satisfaction: 2 nd lowest category How satisfied are you with the temperature in your workspace? Number of respsonses 1, 8, 19% 6, 14%1% 15% 16% 16% 4, 6% 2, - - -2-1 1 2 very dissatisfied very satisfied Overall: 58% of respondents satisfied Distribution of thermal satisfaction 11% of buildings meet acceptability standard Number of buildingsx 6 5 4 2 1 14% 15% 24% 21% 15% 9% 1% 1% -9% 1-19% 2-29% -9% 4-49% 5-5% 6-69% 7-79% 8-89% 9-99% 1% Percent satisfied Percent satisfied: Top 4 points (>=) on 7-point satisfaction scale Air quality satisfaction: rd lowest category How satisfied are you with the air quality in your workspace (i.e. stuffy/stale air, cleanliness, odors)? 1, Number of respsonses 8, 6, 4, 2, 9% 1% 1% 2% 18% 19% 8% - - -2-1 1 2 very dissatisfied very satisfied Overall: 68% of respondents satisfied Distribution of air quality satisfaction Thermal satisfaction, by building type 26% of buildings meet acceptability standard Mean Scores - Thermal Comfort Number of buildingsx 6 5 4 2 1 1% 1% 8% 19% 2% 25% 15% 9% 2% LEED (n=1), LEED mixed (n=1) mode compared (n=5) compared to CBE to CBE database database (n=257) (n=257) mixed mode median:.62 leed median:.42 db median: -.1-9% 1-19% 2-29% -9% 4-49% 5-5% 6-69% 7-79% 8-89% 9-99% 1% Percent satisfied Percent satisfied: Top 4 points ( ) on 7-point satisfaction scale - % 25% 5% 75% 1% Data for evolving green building design criteria Center for the Built Environment (CBE) http://www.cbe.berkeley.edu Page 5
Roomvent 27: 1 th International Conference on Helsinki, June 1-15, 27 Air quality satisfaction, by building type Green buildings and acoustic satisfaction Mean Scores - Air Quality LEED (n=1), LEED mixed (n=1) mode com (n=5) pared compared to CBE to database CBE database (n=257) (n=257) Mean Scores - Acoustic Quality LEED (n=1) compared to CBE database (n=257) mixed mode median: 1.95 leed m edian: 1.21 db m edian:.21 leed median: -.15 db median: -.25 - % 25% 5% 75% 1% - % 25% 5% 75% 1% Green Building Confessions Green Building Confessions 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% * (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 Overall Satisfaction - Air Quality HOK Buildings Compared to CBE Database - % 25% 5% 75% 1% Overall Satisfaction - Thermal Comfort HOK Buildings Compared to CBE Database - % 25% 5% 75% 1% Example 6: Field study research on air movement Window-ventilated open-plan office building CBE IEQ survey for background two seasons ~1 occupants/season (half of the building population) Repeated right now survey two week test period each season 8 occupants/season Total more than 2 surveys Ambient measurements air and globe temperatures, humidity, and air velocity at 8 workstations Continuously during both seasons Center for the Built Environment (CBE) http://www.cbe.berkeley.edu Page 6
Roomvent 27: 1 th International Conference on Helsinki, June 1-15, 27 Desktop indoor climate monitor (ICM) ICMs Shielded Dry Bulb Anemometer (air speed) Globe Temperature Monitoring station and voting box units, Fishman and Pimbert, 1978 ICM application will be described later.. Right now survey air movement questions Right now survey: air movement preference question want less % (n=1) want less 4% (n=41) no change 52% (n=54) want more 45% (n=468) no change 68% (n=699) want more 28% (n=288) Summer, N = 14 Winter, N = 128 Many more people wanted more air movement than less Thermal sensation and air movement preference Higher velocities--above the.2 m/s draft limit 1% of the measured velocity >.2 m/s, N=194 Center for the Built Environment (CBE) http://www.cbe.berkeley.edu Page 7
Roomvent 27: 1 th International Conference on Helsinki, June 1-15, 27 Air movement preferences >.2 m/s Effect of temperature on perceived air quality no change 45% want less 5% want more 5% Overall Satisfaction - Air Quality BCC Compared to CBE Database acceptable air motion (55%) want more 71% no change 2% want less 6% unacceptable air motion (45%) summer winter Summer average indoor temperature 24.2ºC, average thermal sensation.4 Winter average indoor temperature 22.8ºC, average thermal sensation.1 - % 25% 5% 75% 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 Center for the Built Environment (CBE) http://www.cbe.berkeley.edu Page 8