Sustainable Buildings Canada Breakfast Series

1. Real Performance of Green Buildings:
The Role of Delivered Performance to Achieve
Real Savings
Stephen Carpenter
Enermodal Engineering
June 3, 2009

2. Background
USGBC presented results that US LEED projects
saved ~25% energy compared to standard buildings
Lstibrek said “LEED plaques should come with screws
until performance is proven”
“Gifford makes the controversial case that LEED
certified buildings use more energy than comparables,
not less- as much as 29% more.”
Creating energy and resource efficient buildings

3. Background
What are results for Canada?
Enermodal is leading green consultant in Canada
with 43 LEED certified projects
45% of all LEED Canada NC certified buildings
Results for 6 LEED buildings presented
Show how Delivered Performance helps buildings
achieve their potential
Creating energy and resource efficient buildings

4. How Do We Determine if Green Buildings
Really Work?
Very little data on real performance of green
buildings
Some well known green buildings have not shown
significant savings over other new buildings
Most claims are based on design phase computer
simulations
Simulations must be calibrated to real operation,
weather etc.
Better to compare utility bills to utility bills
Creating energy and resource efficient buildings

5. How Do Conventional and Green
Buildings Perform?
Creating energy and resource efficient buildings

6. Energy Use of All Buildings – By Age of
Construction
Survey of Energy Use in Canadian Buildings 2000
500
400
100 93
kWh/m2
300
200
100
0
Before 1920 1920 - 1959 1960s 1970s 1980s 1990s
Year built
Ref: Commercial and Institutional Building Energy Use, NRCAN 2002
Sample size: 137,039 buildings, 302,570,981 sq m
Creating energy and resource efficient buildings

7. Monitored Performance of 6 LEED Projects
Creating energy and resource efficient buildings

8. Water Savings: A Tale of Two Fire Stations
Station 79 was intended to be duplicate of 78
79 was greened up but floor plan unaltered
Creating energy and resource efficient buildings

9. Water Use at Two Identical Fire Stations
68% annual water savings
Creating energy and resource efficient buildings

10. Are Green Buildings Performing Up to
Expectations?
The Role of Delivered Performance
Creating energy and resource efficient buildings

11. What is Delivered Performance?
Comprehensive post-construction consulting
service that delivers better performing buildings
Single packaged service that includes:
– Fundamental Commissioning
– Best Practice Commissioning
– M&V
– Building airtightness review and testing
– Building IAQ Testing
– Green Education and Promotion (optional)
The whole is more than the sum of the parts
Creating energy and resource efficient buildings

12. What is Delivered Performance?
A mindset where we are designing buildings to
achieve real savings not predicted savings
Don’t do things that don’t save energy
– occupancy sensors in hospital corridors
Do do things that save energy even if no sim credit
– instantaneous heaters and avoid hot water recirc system
Our role is to work with the owner to get the
building to perform as close as possible to its
potential and identify action the owner could take to
further improve operation
Creating energy and resource efficient buildings

13. Delivered Performance in Practice
LEED-NC currently assesses building energy
performance based on simulated performance
But energy simulations are really just an indication of
the potential for a design to be efficient… relative to a
particular reference case… and under a specific set
assumptions
Need to “calibrate” the energy simulation
Creating energy and resource efficient buildings

14. Calibrated Energy Consumption
Most simulations do not account for all energy uses in
a building – sometimes “ignored” energy in LEED
compliance simulations can be very significant:
– Exterior lighting, Kitchens, Servers, Elevators, Humidification
Energy uses can be highly dependent on occupant
behaviour and hard to predict
Creating energy and resource efficient buildings

15. Occupants Affects on Energy Consumption
4.8 L/100 km 11.5 L/100km
Creating energy and resource efficient buildings 15

16. Calibrated Energy Consumption
Example Building Calibration Process:
1. Weather
2. Exterior lights
3. Ground loop temperature revision
Preliminary Model Measured Performance
4. Kitchen electricity
5. Kitchen process loads
6. Humidification
7. Kitchen gas use
8. Heat pump spec update
9. Elevator electricity
10. Ground loop pump update
11. Ground temperature updates
1 2 3 4 5 6 7 8 9 10 11
Calibration Iteration
Creating energy and resource efficient buildings

17. Process 5
1
3
5
2 4
Creating energy and resource efficient buildings

18. Importance of Energy Monitoring
Initial monitored results were 15% above predicted
Commissioning with M&V reduced to 2% below predicted
Annual Energy Performance
1000000
800000
ekWh
600000
400000
200000
Dec. 2007 - Feb. 2008 March - May 2008 June - August 2008 Sep. - Nov. 2008
Baseline Actual Potential
Creating energy and resource efficient buildings

19. Case Study: TRCA Restoration Services
Design Phase Simulation Results
Annual
Energy
ekWh/m2
LEED Status: Platinum LEED Energy Savings: 65% (10 pts)
Creating energy and resource efficient buildings

20. Case Study: TRCA Restoration Services
Actual Performance
250
Is this just luck?
200
Annual
Energy
150
ekWh/m2
100
50
Simulated
Actual
0
Feb '05 (SL) Mar '05 (SL) Aug '06 (CBIP) Feb '07 (Review) May '07 to Apr '08
Creating energy and resource efficient buildings

21. Case Study: TRCA
Changes to “calibrate” energy simulation:
Update with weather information
Add in “kitchen processes” (including cooking appliances
and make-up air/exhaust system)
Add in energy use related to the snow melt system
Update affecting ground loop pump energy calculation
Creating energy and resource efficient buildings

22. Case Study: Natural Gas
Contractor had crossed floor loops: office t’stat
controlling floor heat in storage room.
Investigations revealed user issues: garage doors being
left open, unit heater operation, t-stat settings.
Creating energy and resource efficient buildings

23. Case Study: Electricity
1 meter not working, filled in the gaps with manual
readings from client
Faulty heat pump: supplier blamed system, contractor
blamed supplier (but no one measured any parameters)
Creating energy and resource efficient buildings

24. Case Study: Water
Rain water cistern, low-flow fixtures, composting toilets.
Showers not being used as frequently as anticipated?
Creating energy and resource efficient buildings

25. Comparison of Actual to Predicted Water Use
Creating energy and resource efficient buildings

26. Conclusions
Initial data indicates LEED buildings appear to offer
significant energy and water savings
Actual Energy use ~ 200 kWh/m2
M&V critical to diagnose problems and improve operation
over time.
Calibrated simulation can accurately potential building
performance
Poor agreement between predicted and actual water use
Creating energy and resource efficient buildings

27. www.enermodal.com
Creating energy and resource efficient buildings