Energy Savings by Retrofitting Multi-Unit Residential Buildings: Case Studies Marianne Touchie, Kim Pressnail & Ekaterina Tzekova University of Toronto BEST 3, Atlanta, Georgia April 3 rd, 2012
Outline Energy use in MURBs Study Methodology Assumptions Case Studies: Rental Properties Condominium Properties Conclusions and Lessons Learned 2
MURBs in Toronto, Canada MURB Housing starts in the Toronto Area 28,200 Housing Stock 30% 15,900 Residential GHG Emissions 1950 1960 1970 1980 1990 2000 40% 3 30 year design life Figure Adapted from T. Kesik and I. Saleff. 2009. Tower renewal guidelines. University of Toronto.
Methodology Building Owner/Manager Interviews Pre and Post-Retrofit Energy Consumption Analysis Weather normalization Energy Cost Savings Financial Performance of Retrofit Measures 4
Historical Utility Costs 5 Cost of Electricity/kWh and Natural Gas/m 3 $0.50 $0.40 $0.30 $0.20 $0.10 $0.00 2003 2004 2005 2006 2007 2008 2009 2010 $2.50 $2.00 $1.50 $1.00 $0.50 Sources for Figure: City of Toronto. 2010. http://www.toronto.ca/utilitybill/water_rates.htm; E Ontario Energy Board 2010 http://www.ontarioenergyboard.ca/oeb/consumers/electricity/electricity+prices; Ontario Energy Board. 2010 http://www.oeb.gov.on.ca/oeb/consumers/natural+gas/natural+gas+rates/natural+gas+rates+-+historical; $- Cost of Water and Wastewater/m 3 Electricity Natural Gas Water
Projected Utility Costs $30 Average Utility Cost per m 2 $25 $20 $15 Electricity $10 Natural Gas $5 Water $- 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 6
Case Study 1 (Rental) Pre-Retrofit Condition: 32 suites Built in 1930 s High maintenance costs Frequent equipment breakdowns 7 7
Case Study 1 (Rental) Retrofit Strategy: Windows Attic insulation Boiler controls and steam traps Common area lighting Faucets, showers, toilets 8 8
Case Study 1 (Rental) 60,000 40% 50% 4,000 Actual Performance Total Project Cost $74,200 Natural Gas Use (m 3 ) 45,000 30,000 15,000 3,000 2,000 1,000 Water Use (m 3 ) Tonnes CO 2 e avoided/annum Simple Payback 46 IRR over 10 years 10% Net Present Value (4% Discount Rate) 6.5 years $27,000 0 0 9 9
Case Study 2 (Rental) Pre-Retrofit Condition: 128 suites Built in 1970 Roof reaching end of life Original, single-glazed windows 10 10
Case Study 2 (Rental) Retrofit Strategy: Improved building envelope (replace windows, balcony doors and roof) Reduced reliance on fossil fuels (install a solar thermal hot water system) 11 11
Case Study 2 (Rental) Annual Natural Gas Use (m 3 ) 500,000 21% 400,000 300,000 200,000 100,000 0 2007 2008 2009 2010 2011* Projected Natural Gas Actual Natural Gas Actual Performance Total Project Cost (after incentives) Tonnes CO 2 e avoided/annum Payback based on energy cost savings Payback based on energy cost savings and increased rental income $568,000 160 16 years 3 years 12 12
Case Study 3 (Condominium) Pre-Retrofit Condition: 210 suites Built in 1974 Excessive energy bills Wanted to avoid borrowing costs 13 13
Case Study 3 (Condominium) Retrofit Strategy: Boiler Replacement Air Handling Unit (AHU) Retrofit Toilet Replacement Chiller Replacement 14 14
Case Study 3 (Condominium) 600,000 28% 29% 90,000 Actual Performance Natural Gas Use (m 3 ) 400,000 200,000 60,000 30,000 Water Use (m3) Total Project Cost $678,000 Tonnes CO 2 e avoided/annum Simple Payback 277 4 years Net Present Value $267,000 0 0 15 15
Case Study 4 (Condominium) Pre-Retrofit Condition: 116 suite Occupied in 2001 Investigation into solar energy led to discovery of other energy savings measures 16 16
Case Study 4 (Condominium) Retrofit Strategy: Lighting Retrofit CO Monitor Installation Boiler Replacement Installation of Variable Frequency Drive on Make- Up Air Unit 17 17
Case Study 4 (Condominium) 400,000 31% 12% 1,600,000 Actual Performance Natural Gas Use (m 3 ) 300,000 200,000 100,000 1,200,000 800,000 400,000 Electricity Use (kwh) Total Project Cost (after incentives) Tonnes CO 2 e avoided/annum Simple Payback $146,000 153 IRR over 10 years 45% 2.4 years Net Present Value $260,000 - - 18 18
Summary of Retrofit Impacts Cost of Avoided GHG Emissions ($/tco 2 e) 19 $1,200 $1,000 $800 $600 $400 $200 $83/tCO 2 $- Lighting/ Exhaust /MAU (Bldg 4) Toilet Replacement (Bldg 3) Lighting Retrofit (Bldg 1) Water Fixture Replacement (Bldg 1) Boiler Replacement (Bldg 4) Chiller upgrade (Bldg 3) Boiler Replacement (Bldg 3) Boiler Controls/Wndw Replace/Attic insulation (Bldg 1) 0 2 4 6 8 10 Simple Payback (yrs)
Lessons Learned Planning: Whole Building Approach Establish Baseline Utility Use Enhance Existing Maintenance Projects http://www.stlucieco.gov/planning/planning.htm Quick Payback + Longer Payback Items 20 20
Lessons Learned Financing: Energy Conservation Incentives Financial Analysis Tools Construction: COMMUNICATION! Operations: Ongoing control 21 hwww.mediatonet.com/financing.html, www.reggin.ca/hvac.htm, www.afmcontrols.com/, ableandbakerdesign.blogspot.com/2009/09/1968-airstream-retrofit-window.html 21
For more information Energy Retrofit Case Studies on the TowerWise Website towerwise.ca/case_studies Marianne Touchie marianne.touchie@utoronto.ca 22 22