Deep Energy Retrofit of a HighRise MURB

Transcription

1 Deep Energy Retrofit of a HighRise MURB COLIN SHANE M.Eng., P.Eng. RDH BUILDING SCIENCES INC. SAN FRANCISCO, CA

2 AIA Credits National Institute of Building Sciences Provider #G168 Credit(s) earned on completion of this course will be reported to AIA CES for AIA members. Certificates of Completion for both AIA members and non-aia members are available upon request. This course is registered with AIA CES for continuing professional education. As such, it does not include content that may be deemed or construed to be an approval or endorsement by the AIA of any material of construction or any method or manner of handling, using, distributing, or dealing in any material or product. Questions related to specific materials, methods, and services will be addressed at the conclusion of this presentation.

3 AIA Credits Learning Objectives Participants will: 1. Learn how to link the performance of individual building enclosure components in a holistic framework to achieve high-performance buildings. 2. Explore, through built case studies, how building envelope design determines overall energy conservation and sustainability capabilities 3. Learn innovative practices for avoiding heat loss as well as moisture and air infiltration in enclosure design for healthy new and existing buildings. 4. Understand the role of building enclosure commissioning in the design, construction, and operation and maintenance of commercial facilities.

4 Outline à Why multifamily buildings? à Energy consumption & opportunities for conservation à Case study of an energy efficient multifamily retrofit 4 of

5 Why Multifamily Buildings? Growing proportion of the housing stock Large emitters of GHGs in cities 55% of GHGs from Buildings in Vancouver Many challenges split incentives, poorly insulated envelopes 5 of

6 Average MURB EUI Pacific Northwest Average EUI: 68 kbtu/sf per year Annual Energy Use Intensity, kwh/m kbtu/sf Gas Electricity - Common Electricity - Suite Building ID Energy Consumption and Conservation in Mid- and High-Rise Residential Buildings 6 of

7 Multifamily Energy Efficiency Opportunities Good Retrofit Best Retrofit Wall insulation to R-10 Windows double glazed, argon fill, low-e, low conductive frame Air sealing Wall insulation to R-18 Windows triple glazed, argon fill, low-e, low conductive frame Air sealing Heat Recovery Ventilation Space Heating EUI, kwh/m kbtu/sf 60% Less Space Heat Energy 12 kbtu/sf 38 90% Less Space Heat Energy 3 kbtu/sf 7 of Current Average Good Retrofit Best Retrofit 10

8 The Approach: Passive Design Reduce the demand for heating, cooling and ventilation energy through passive design strategies Well-insulated building enclosure: walls, roof, windows Airtight construction Heat recovery ventilation Combine with planned renewals work for cost-effectiveness 8 of

9 Case Study: Deep Energy Multifamily Retrofit Started with a condition assessment Progressed to full building enclosure renewal, incorporating energy efficiency measures Project Timeline Monitoring & Testing BE Upgrades 1 year M&V Mechanical upgrades 1 year M&V Year & ongoing 9 of

10 Case Study Background 13 storey multifamily residential building in Vancouver, BC 37 two-bedroom units Constructed in mid 1980s Building renewals pursued at decision of owners to upgrade original building enclosure 10 of

11 Existing Building Enclosure Assessment Exposed concrete walls, nonthermally broken aluminum frame double glazed windows Some window interface water leaks, air leakage Some concrete damage and concerns with PT cables Existing walls R-4 Existing windows R-1.8 ig of Original detail drawing of a window head and sill, colour

12 Existing Mechanical System Assessment Original mechanical systems largely in place Electric baseboard heating Gas-heated make-up air for ventilation (to corridors) 14 decorative gas fireplaces at upper floor suites some replaced by owners Hot-water boiler & tanks replaced few times before 12 of

13 Building Enclosure Renewal Primary Drivers Replace aging building enclosure components Primarily windows Repair water ingress issues Improve durability and reduce future maintenance costs Improve comfort in suites Create a modern aesthetic Increase property value and save some energy 13 of

14 Typical Year Energy Consumption Metered energy consumption 71 kbtu/sf per year Total energy costs $66,000/yr ($1,800/suite) Only 36% paid directly by suite owners, balance paid within condo fees Monthly Energy Consumption, ekwh 80,000 70,000 60,000 50,000 40,000 30,000 20,000 10,000 - Suite Electricity, kwh Common Electricity, kwh Gas, ekwh Common Electricity 18% Suite Electricity 36% Gas 46% Annual Breakdown 14 of

15 Benchmarking Against Multifamily Buildings Pre-retrofit EUI: 71 kbtu/sf per year Annual Energy Use Intensity, kwh/m kbtu/sf Gas Electricity - Common Electricity - Suite Building ID Energy Consumption and Conservation in Mid- and High-Rise Residential Buildings 15 of

16 Evaluating Existing Building Energy Consumption Building energy model calibrated to metered data to evaluate energy consumption by end-use and potential Energy Efficiency Measures Plug and Appliances (Suites) 8% Lights - Suite 7% Equipment and Ammenity (Common) 16% Electric Baseboard Heating 22% Fireplaces 9% Lights - Common 2% Hot Water 11% Ventilation Heating 25% 16 of

17 Case Study: Window Replacement Options: Double glazed, metal frame windows (minimum code requirement) Double glazed, low conductivity frame Triple glazed, low conductivity frame Window Double Glazed, Aluminum Frames Double Glazed, Fibreglass Frames Triple Glazed, Fibreglass Frames Estimated Annual Energy Savings Estimated % Savings $1,900 3% $7,600 7% $11,000 10% 17 of

18 Case Study: Window Replacement Incremental Payback Choosing a more energy efficient window will pay back in energy savings Double or triple glazed windows with low conductivity frames compared to code minimum Incentive programs help offset cost, improve payback Double Glazed, Fibreglass Frames Triple Glazed, Fibreglass Frames Simple Payback Simple Payback Including Incentives 5 years <1 year 14 years 6 years 18 of

19 Building Enclosure Renewals Performed Over clad and exterior insulate walls (R-16 effective) New R-6 tripled glazed fiberglass windows New roof and deck membranes Existing Improve air-tightness Overall new enclosure R-value R-9.1 vs R-2.8 original Next Ventilation retrofit Upgraded 19 of

20 Building Enclosure Renewals $3.6M renewals project, 7 month construction period Work primarily from exterior with access to suites for window installations 20 of

21 Exterior Insulation, Stucco & Metal Panel Overcladding 21 of

22 Triple Glazed Fiberglass Frame Windows 22 of

23 Completed Building Enclosure Renewals 23 of

24 Measured Savings 33% electricity savings Electricity Consumption, kwh 90,000 80,000 70,000 60,000 50,000 40,000 30,000 Calibrated Model Pre-Retrofit Calibrated Model Post-Retrofit 20,000 10,000 - Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov 24 of Dec

25 Calibrated Model Annual Energy Savings Measured Savings: 63% electric kbtu/sf kbtu/sf 19% Savings baseboard heating 20% gas fireplaces 33% electricity 2% gas EUI, kwh/m % total energy = 215 MWh per year - Pre-Retrofit Post-Retrofit Miscellaneous Electrical Lights Hot Water Ventilation Heating Fireplaces Electric Baseboard 25 of Heating

26 Benchmarking Against Multifamily Buildings Annual Energy Use Intensity, kwh/m 2 Pre-retrofit: 71 kbtu/sf per year Post-retrofit: 56 kbtu/sf per year kbtu/sf Gas Electricity - Common Electricity - Suite Building ID Energy Consumption and Conservation in Mid- and High-Rise Residential Buildings 26 of

27 Next Proposed Heat Recovery Ventilators HRVs to provide direct continuous ventilation to each suite Suite compartmentalization air sealing between adjacent suites and corridors Measure energy savings Impact on occupants opening windows and space heating energy? 27 of

28 Outcomes Measured 19% overall energy savings through passive design retrofit 63% electric baseboard heating savings Energy efficiency measures implemented at the time of planned renewals keep the incremental cost of upgrades low Replicating the success of this project is an opportunity for the entire industry 28 of

29 Questions COLIN SHANE M.Eng., P.Eng.

30 Airtightness Testing Overall measured average enclosure airtightness improvement of approximately 55% Estimated 50% for modeling 30 of

31 Potential Energy Efficiency Measures Wall insulation with low conductivity cladding attachment Reduced thermal bridging Windows Double & triple glazed fiberglass frame Airtightness improvement Roof insulation Heat recovery ventilation Fireplace upgrade Make-up air unit (ventilation) 31 of

32 Project Partners BC Hydro BC Homeowner Protection Office (HPO) FortisBC NRCan City of New Westminster City of North Vancouver City of Richmond City of Surrey Enbridge Gas City of Vancouver BC Sustainable Energy Association The Owners 32 of

33 Typical Multifamily Operating Costs Maintenance (eg., wash the windows) 30% Repairs (eg., fix the broken gate) 10% Capital reserve (eg., new boiler in 10yrs) 10% Insurance and administration 20% Staffing and miscellaneous 10% Utilities hydro, gas, water/sewer 20% 20% Maintenance 30% Repairs Capital Reserve 10% Insurance & Admin 10% Staffing & Misc 20% 10% Utilities 33 of

34 Why Multifamily Buildings? Poorly insulated building enclosures 34 of

35 Why Multifamily Buildings? Poorly insulated building enclosures Selling units vs. comfortable living and saving energy Glass House in downtown Winnipeg 35 of

36 Multifamily Energy Consumption Trends Total Energy Space Heat Energy 65 kbtu/sf 30 kbtu/sf 36 of 2005

37 Typical Energy Consumption by End-Use Approximately half of typical multifamily energy consumption in the Pacific Northwest is for heating Other Electrical, 25% Electric Baseboard Heating, 12% Fireplaces, 18% Lights, 10% Hot Water, 16% Ventilation Heating, 19% 37 of

38 Multifamily Energy Efficiency Opportunities Building enclosure Insulation High performance windows Air sealing Mechanical High efficiency equipment and systems Heat recovery ventilation Demand controlled ventilation (parkades) Lighting CFLs, LEDs Occupancy sensors in common areas 38 of

39 Cost Payback Analysis Energy Efficiency Measure / Incremental Upgrade Low Conductivity Cladding Attachment Double Glazed Fibreglass Windows Triple Glazed Fibreglass Windows % Total Energy Savings (% Electrical Heat Savings) $ Savings per year Incremental Cost with Utility Incentives Simple Payback 4% (19%) $4,800 $0 Immediate 7% (30%) $7,600 $2, years 10% (44%) $11,000 $60,000 6 years Airtightness 2% (7%) $1,800 $0 Immediate Fireplace Replacement 2% (8%) $2,100 $14,000 7 years In-Suite HRV Installation 6% (-32%) -$4,400 $74,000 n/a Make-up Air Unit Replacement Enclosure EEMs (triple glazed) Enclosure & Mechanical EEMs (triple glazed) 5% (0%) $1,600 $23, years 20% (87%) $21,900 $60, years 30% (62%) $19,700 $166, years 39 of

40 Metered Energy Data Monthly Energy Consumptoin, ekwh Metered data from BC Hydro and FortisBC 100,000 Suite Electricity, kwh 90,000 Common Electricity (Strata), kwh Gas, ekwh 80,000 70,000 60,000 50,000 40,000 30,000 20,000 10,000 0 Jul 2006 Sep 2006 Nov 2006 Jan 2007 ar 2007 ay 2007 Jul 2007 Sep 2007 Nov 2007 Jan 2008 ar 2008 ay 2008 Jul 2008 Sep 2008 Nov 2008 Jan 2009 ar 2009 ay 2009 Jul 2009 Sep 2009 Nov 2009 Jan 2010 ar 2010 ay 2010 Jul 2010 Sep 2010 Nov 2010 Jan 2011 ar of ay 2011 Jul 2011

41 Measurement & Verification Confirm energy savings Ensure that energy efficiency measures are performing as designed Standard: International Performance Measurement and Verification Protocol (IPMVP) Make a plan Collect data energy and other variables Analyse results 41 of

42 Case Study Building M&V Plan 1 year measurement period Calibrated simulation approach Routine adjustments: weather Non-routine adjustments: new DHW boiler Metering primarily through utility meters 42 of

43 Measured Savings 2% gas savings 70,000 60,000 Calibrated Model Pre-Retrofit Calibrated Model Post-Retrofit Gas Consumption, ekwh 50,000 40,000 30,000 20,000 10,000 - Jan Feb Mar Apr May Jun Jul Aug Sept Oct Nov 43 of Dec

44 Measured Savings 19% total building energy savings Total Energy Consumption, ekwh 160, , , ,000 80,000 60,000 40,000 20,000 Calibrated Model Pre-Retrofit Calibrated Model Post-Retrofit - 44 of Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec