The role of delivered performance june2009

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

www.enermodal.com Creating energy and resource efficient buildings

The role of delivered performance june2009

by Sustainable Buildings Canada

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