Post-Occupancy Evaluations of High-Performance Homes

1. POST-OCCUPANCY EVALUATIONS OF
HIGH-PERFORMANCE HOMES
Tenna Florian
Hazem Rashed-Ali

2. Hacienda Ja Ja: A High Performance Home Lake | Flato Architects

3. “THERE are NO ZERO-ENERGY HOUSES, only
ZERO-ENERGY FAMILIES.”
- Andy Shapiro, energy consultant

4. TEAM
Architect: Lake | Flato Architects (Tenna Florian, Bill Aylor, Josh Canez, Gus Starkey)
Contractor: Truax Construction (Jeff Truax)
Interior Design: M. Robbins Black (Robin Black)
Landscape Design: Rialto Studio (Pete Hinton)
Lighting Design: George Sexton Associates (George Sexton)
Structural Engineer: Jack Harrison
Solar: Cinco Solar
Mechanical: Southwest Mechanical
STATS
Construction Period: January 2009 to May 2010 (move in)
Conditioned Space: 2,330 square feet
Unconditioned Space: 950 square feet

16. LEED Highlights:
Platinum Project: 87 points needed and 89.5 achieved
Locations and Linkages: 10 of 10 points available
infill, previously developed, and good access to transit
Sustainable Sites: 14.5 of 22 points available
site stewardship, native landscaping, reduced heat island effect, permeable lot
Water Efficiency: 11 of 15 points available
rainwater harvesting, irrigation demand reduction, and highly efficient fixtures
Energy & Atmosphere: 33 of 38 points available
optimize energy performance, efficient hot H2O systems, appropriate refrigerants
Materials and Resources: 7.5 of 16 point available
environmentally preferable products, waste reduction plan
Indoor Environmental Quality: 11 of 21 points available
moisture control, outdoor air ventilation, local exhaust, ventilated garage

17. Water Efficiency: 11 of 15 points available
rainwater harvesting, irrigation demand reduction, and highly efficient fixtures

18. Energy & Atmosphere: 33 of 38 points available
optimize energy performance, efficient hot water systems, appropriate
refrigerants

19. Hacienda Ja Ja: A High Performance Home Lake | Flato Architects

20. POST-OCCUPANCY EVALUATION
OBJECTIVES:
• Verify overall house energy use,
• Compare actual energy use with predicted
energy use,
• Identify potential for performance
improvement,
• Assess success of design strategies,
Hacienda Ja Ja

21. MONITORING PERIOD:
System installed on Nov. 11, 2010 to present.
Monitoring period reported: January 1, 2011 through December 31, 2011.
Four small periods of communication loss due to power outage (less than 1 hr. each).
One larger period of communication loss (June 13 through 17).
BUILDING OCCUPANCY:
Building not regularly occupied during monitoring period.
Occupancy period approximately one third of the year.

22. 100%
90%
80%
70%
60%
Percentage of Days
50%
40%
30%
20%
10%
0%
Jul-11
Dec-11
Jun-11
Sep-11
Mar-11
Feb-11
Aug-11
Nov-11
Apr-11
Jan-11
May-11
Oct-11
Monitored/ Occupied Monitored/ Not Occupied Not Monitored
Month
Monitoring / Occupancy Period

23. MONITORING EQUIPMENT:
eMonitor:
One eMonitor 12r installed.
Monitors PV power production &
energy use at circuit level.
System online interface
HOBOs:
Five HOBO U12-012 Data loggers
installed.
Monitors temperature, humidity,
lighting levels.

24. LOCATION OF MONITORING EQUIPMENT
eMonitor-12r
Hobo-U12-012

26. Post-Occupancy Evaluation
Monitoring equipment
• eMonitor:
• One eMonitor 12r installed.
• Monitors PV power production
& energy use at circuit level.
• System online interface
• HOBOs:
• Five HOBO U12-012 Data
loggers installed.
• Monitors temperature, humidity,
lighting levels.

27. THE FOLLOWING ISSUES WERE IDENTIFIED / CORRECTED
DIRECTLY OR PARTIALLY DUE TO MONITORING SYSTEM:
Kitchen Instantaneous Water Heater Usage
Solar Domestic Hot Water Pump
HVAC Dehumidifier Settings
PV System Blown Circuit

28. Green Switch
turned on
User in
house
User left heater on while building was unoccupied resulting in approx. 7
kWh/day usage.
Issue identified from monitoring, resulting in user changing behavior.

29. 3% 7% 1% 17%
20%
0%
51%
Data taken from 24 hr. time frame Turning off the Kitchen Water
Heater reduced the house’s total
Energy Usage 20%.
9% 1%
4% 22%
0%
64%
Data taken from 24 hr. time frame

30. User changed
settings
User left AC on dehumidifier setting while the building was unoccupied- resulting
in a high AC energy usage.
Issue identified through monitoring and resulted in user changing behavior.

31. Problem identified (system
off-line).
Problem fixed (system
online)
Pump stopped working, hot water provided by auxiliary electric heating.
Issue identified through user observation (hot water insufficient), and confirmed using
monitoring system.

32. Problem fixed
Problem started
Low PV production issue Identified by user.
PV installer initially blamed resource variability.
Upon user insistence, inspection showed a blown circuit in resulting in 50%
reduction of production.

33. 2,000
Preliminary Results – Overall Energy Use:
1,500
Energy Use (kWh)
1,000
500
0
-500
Jan-11
May-11
Jun-11
Aug-11
Feb-11
Apr-11
Jul-11
Mar-11
Nov-11
Oct-11
Sep-11
Dec-11
Months
Utility Energy Use Building Energy Use PV Poduction

34. OVERALL ENERGY USE - 2011:
14,000
12,000 11,288
10,000 9,372
Energy Use (kWh)
8,000
6,000
4,000
1,916
2,000
0
2011 Energy Use Totals
Utility Energy Use Building Energy Use PV Poduction

35. ENERGY USE INTENSITY (EUI) - 2011:
18.0
16.5
16.0
Energy Use Intensity (kBtu/ft2/yr)
14.0 13.7
12.0
10.0
8.0
6.0
4.0
2.8
2.0
0.0
2011 Energy Use Intensity
Utility Energy Use Building Energy Use PV Poduction

36. PRELIMINARY RESULTS: energy + cost
HISTORY

37. ENERGY END USES - 2011:
1,600
1,400
1,200
HVAC
1,000
Energy Use (kWh)
Dryer
800 Oven
600 Kitchen Water
Heater
DHW
400
Lights /Plug Loads
200
0
Feb-11
Apr-11
Jul-11
Oct-11
Jun-11
Sep-11
Nov-11
May-11
Jan-11
Dec-11
Mar-11
Aug-11
Months

38. ENERGY END USES EUI - 2011:
2.50
2.00
End Energy Use Intensity (kBtu/ft2/yr)
HVAC
1.50 Dryer
Oven
Kitchen Water
1.00
Heater
DHW
Lights /Plug Loads
0.50
0.00
Jul-11
Sep-11
Aug-11
Mar-11
Jun-11
Dec-11
Jan-11
Feb-11
Apr-11
May-11
Oct-11
Nov-11
Months

39. ENERGY END USES - 2011:
1,274, 11%
399, 4%
Lights /Plug Loads
1,057, 10% DHW
Kitchen Water
153, 1% Heater
21, 0% Oven
Dryer
HVAC
8,113, 74%
Total Energy End Uses (kWh)

40. ENERGY END USES INTENSITY - 2011:
1.87, 11%
0.58, 4%
Lights /Plug
Loads
1.55, 10% DHW
Kitchen Water
Heater
0.22, 1%
Oven
0.03, 0%
Dryer
HVAC
11.88, 74%
End Energy Use Intensity (kBtu/ft2)

41. COOLING SEASON DEMAND:
6.0 110
5.0 100
4.0 90
Building
3.0 80 Demand
Power Demand (kW)
Temperature (F)
Utility Energy
2.0 70 Use
1.0 60 PV Production
0.0 50
AC USE
-1.0 40
Ambient
Temperature
-2.0 30
-3.0 20
13:00
14:00
0:00
1:00
2:00
3:00
4:00
5:00
6:00
7:00
8:00
9:00
10:00
11:00
12:00
15:00
16:00
17:00
18:00
19:00
20:00
21:00
22:00
23:00
Hour of Day
Hottest Day - August 28 (Building Unoccupied)

42. COOLING SEASON DEMAND:
6.0 110
5.0 100
4.0 90
Building
Demand
Power Demand (kW)
3.0 80
Utility
Temperature (F)
2.0 70 Energy Use
1.0 60 PV
Production
0.0 50 AC USE
-1.0 40
Ambient
Temperatur
-2.0 30 e
-3.0 20
16:00
0:00
1:00
2:00
3:00
4:00
5:00
6:00
7:00
8:00
9:00
10:00
11:00
12:00
13:00
14:00
15:00
17:00
18:00
19:00
20:00
21:00
22:00
23:00
Hour of Day
Hottest Occupied Day (August 2)

43. HEATING SEASON DEMAND:
6.0 60
5.0 50
4.0 40
Building
Demand
3.0 30
Power Demand (kW)
Utility
Temperature (F)
2.0 20 Energy Use
1.0 10 PV
Production
0.0 0 AC USE
-1.0 -10
Ambient
Temperatur
-2.0 -20 e
-3.0 -30
16:00
0:00
1:00
2:00
3:00
4:00
5:00
6:00
7:00
8:00
9:00
10:00
11:00
12:00
13:00
14:00
15:00
17:00
18:00
19:00
20:00
21:00
22:00
23:00
Hour of Day
Coldest Day – February 2nd (Building Unoccupied)

44. HEATING SEASON DEMAND:
6.0 90
5.0 80
4.0 70
3.0 60 Building
Demand
Power Demand (kW)
2.0 50
Utility
Temperature (F)
1.0 40 Energy
Use
0.0 30 PV
Productio
-1.0 20 n
AC USE
-2.0 10
-3.0 0
Ambient
Temperat
-4.0 -10 ure
-5.0 -20
6:00
0:00
1:00
2:00
3:00
4:00
5:00
7:00
8:00
9:00
10:00
11:00
12:00
13:00
14:00
15:00
16:00
17:00
18:00
19:00
20:00
21:00
22:00
23:00
Hour of Day
Coldest Occupied Day – November 27th

45. COMPARISON WITH RECS & REM RATE
MODEL: Energy Use Intensity (kBTU/ft /yr)
40
2
37.6 1) Average EUI
based on
35 RECS 2005
data.
30.1
30
Energy Usae Intensity (kBTU/ft2/yr)
2) REM Rate
estimates
25
based on
19.8
design-stage
20 analysis
16.5
3) Actual EUI
15
based on
consumption
10
8.04 from 1/1/2011
through
5 12/31/2011
2.8
0
Average TX Average TX REM Rate REM Rate Hacienda HaHa Hacienda HaHa
Home Home (Mod.) Model (Building Model (Utility EUI (Building EUI (Utility
Energy Use) Energy Use) Eneryg Use) Energy use)

46. PV PRODUCTION: ACTUAL vs. REM RATE
10,000 20 1) Estimated
9,372
system size
9,000 18 (for REM Rate
7,795 model):
8,000 16
14.3 2) Actual System
7,000 14 Size: 7.5
PV Production (kBtu/sq ft)
11.9
PV Production (kWh)
6,000 12 KW
5,000 10
4,000 8
3,000 6
2,000 4
1,000 2
0 0
REM Rate estimates Actual Production

47. DAYLIGHT LEVELS
Average Day - January Average Day - April
100 100
90 90
80 80
Daylight Levels (FC)
Daylight Levels (FC)
70 70
60 60
50 50
40 40
30 30
20 20
10 10
0 0
1 3 5 7 9 11 13 15 17 19 21 23 1 2 3 4 5 6 7 8 9 101112131415161718192021222324
Hour of Day Hour of Day
Average Day - March Average Day - May
100 100
90 90
80 80
Daylight Level (FC)
Daylight Levels (FC)
70 70
60 60
50 50
40 40
30 30
20 20
10 10
0 0
1 3 5 7 9 11 13 15 17 19 21 23 1 3 5 7 9 11 13 15 17 19 21 23
Hours of Day Hours of Day

48. Daylight Levels (FC)
100
0
10
20
30
40
50
60
70
80
90
0:00
1:00
2:00
3:00
4:00
5:00
6:00
7:00
8:00
9:00
10:00
11:00
DAYLIGHT LEVELS
12:00
Hours of Day
13:00
14:00
15:00
16:00
17:00
18:00
Fully Cloudy Day - Occupied - December 21
19:00
20:00
21:00
22:00
23:00

49. CONCLUSIONS
• ROLE OF MONITORING IN IDENTIFYING:
• maintenance issues
• potential for performance improvement.
• OVERALL EVALUATION OF HOUSE ENERGY
PERFORMANCE.
• IMPACT OF IRREGULAR OCCUPANCY
• ACTUAL VS. MODELED ENERGY USE

50. THANK YOU,
Questions?