Energy Consumption in Mid- and High-rise Residential Buildings

Transcription

1 Energy Consumption in Mid- and High-rise Residential Buildings The Myths and Realities of Real Building Energy Performance Warren Knowles P.Eng. January 19, 2011

2 Learning Objectives Understanding of: Energy consumption trends within new and older high-rise buildings (where energy is used / can be conserved). Impacts of design of the building enclosure on energy consumption. Relationship between enclosure air-tightness, suite compartmentalization, and ventilation strategies on energy consumption. How simple calibrated energy modeling can be used to assist with the design. How to comply with current energy code requirements including ASHRAE How to improve performance characteristics of building enclosure assemblies.

3 BC Climate Action Plan By 2020: 33 % reduction in Greenhouse Gas Emissions Energy Efficient Building Strategy -20% energy use per household Clean Energy Act

4 City of Vancouver Greenest City Action Plan 2020 Goals: Carbon Neutral New Buildings 20% Reduction in Energy Consumption and Greenhouse Gas Emissions in Existing Buildings Buildings account for 55% of Greenhouse Gas Emissions How will we get there? Absolute Energy Intensity requirements (kwh/m2/yr) Incentives and other means

5 Multi-Unit High-Rise Residential Building Energy Study Energy consumption of over 60 mid- to highrise Multi-Unit Residential Buildings (MURBs) Constructed between 1974 and 2002 Half of study buildings underwent a full-scale building enclosure rehabilitation Allows for the assessment of actual energy savings from enclosure performance Pre- and post-rehabilitation R-values, airtightness characteristics are compared to energy consumption. Other building performance characteristics as a result of the enclosure improvements are assessed. CMHC SCHL

6 Energy Units Typical energy intensity units - kwh/m 2 /yr or GJ/m 2 /yr in Canada Gas is metered/billed in units of GJ, and electricity in units of kwh Both energy intensities are used in the study 1 kwh = 10 x 100 watt lights bulbs 1 hour 1 kj = Burning a match 1 GJ = kwh (or ekwh)

7 Study Buildings Why High-rise MURBs? 55% of GHGs from Buildings in Vancouver High-rise MURBs largest emitters (COV) Not well understood

8 Study Buildings 39 mid and high rise residential buildings 4,400 residential suites 4,600,000 square feet of floor area $5,000,000 annual energy costs 44,000,000 kwh annual electricity use 173,000 GJ annual gas use

9 Design Characteristics Older Buildings Lower glazing percentage Framed walls Exposed concrete Punched windows

10 Design Characteristics 1990s Buildings Higher glazing percentage Concrete walls Framed wall Window wall and punched windows

11 Design Characteristics - More Recent Buildings High glazing percentage Metal panel cladding Concrete fins Window wall / spandrel panels

12 Top-down vs. Bottom-up Analysis Top down: Annual bulk energy billed known Suggests good overview Problems: Bottom-up: Metering varies (individual for electrical, vs. common for gas) Building features and activities Pools, elevators, fireplaces, lighting, etc. Seasonal conversion efficiencies not known Detailed information available Can identify anomalies or errors in billing data One building at a time Building systems known Modeling software available Occupant Behavior? Better weather data (smart metering data during cold rain events)

13 Monthly Energy Consumption Typical Building kwh Baseline Gas No Space Heat Baseline Suite Electricity No Space Heat

14 Estimated Monthly Heating kwh

15 Energy Intensity kwh/m 2 /yr Average = 213 kwh/m 2 /yr Median = 217 kwh/m 2 /yr Average = 213 kwh/m 2 /yr Std Dev = 42 kwh/m 2 /yr Range = 144 to 299 kwh/m 2 /yr Common Electricity Suite Electricity Gas

16 Distribution of Space Heat Energy % of Total Building Energy Used for Space Heat % Total Energy Which h is Heat 60% 50% 40% 30% 20% 10% Electrical Heat Gas Heat Average of 37% of Energy is used for Space-Heating Average 37% of total building energy is used for heat Of this portion an average of 69% of this energy is from gas 0% Building ID

17 Energy Consumption vs Year of Construction 350 Energy Consumption n - kwh/m 2 /yr Total Energy Space Heat Energy Year of Construction

18 Fuel for Space Heat versus Age of Building kwh/m 2 /yr 160 Gas MAU or Fireplace Space Heat 140 Electric Resistance Space Heat Electric Space Heat Trend 120 Gas Space Heat Trend

19 Space-Heat from Gas Sources % Total Building Heat which is Gas 100% 80% Average of 69%, Majority of Space-Heat Energy from Gas Sources MURBs with fireplaces in majority of suites Hydronic Gas Heat % Space Heat from Gas 60% 40% 20% 0%

20 Current Misconceptions about High-Rise Energy Use 258 kwh/m kwh/m 2 Actual? >213 kwh/m 2 HOUSES HIGHRISES All of Canada BC buildings use approximately 92% of the Canadian average Appears that Common Area Gas Consumption (~50% of total energy use), may not have been included in SHEU data-set

21 Detailed Analysis Heat Transfer

22 Determining Thermals Resistance of Assemblies Model assemblies using THERM 5.2

23 Three-Dimensional Components Isothermal planes modeling technique Cladding (Stucco) Exterior Insulation (Mineral Wool) Steel Stud Interior Gypsum Wall Board Exterior Sheathing Steel Z-girts Stud Sill Track Concrete Floor Slab Stud Head Track 1) A cross-section is created on the horizontal blue plane. 2) Components that vary along the length of the wall are modeled using THERM and equivalent homogeneous materials are created. Horizontal Cross-section Vertical Cross Section 3) A cross-section is created on the vertical green plane. 4) The assembly is modeled on this plane using THERM and the equivlanet homogenous materials created in Step 2 are used in place of inhomogeous components as illustrated at left.

24 Three-Dimensional Components Verify with HEAT 3D and previous Guarded Hot-Box testing results HEAT 3D model of 6 Stainless Steel Clip Temperature Isotherms for 6 Stainless Steel Clip Temperature Isotherms through stainless clip horizontal cut

25 R-Values Down Jacket R 3-5 R 2 Acoustic Ceiling Tile

26 Framed Wall with Batt Insulation 3.5 Fibreglass R 12 or R14 Steel stud wall assembly with concrete slab R 3-4

27 Exterior Insulated Wall 3 XPS Insulation R 15 Exterior insulated wall assembly R 7.5

28 Concrete Wall R5 1 XPS Insulation Concrete wall with steel stud furring R Fibreglass R 7 (R3 without XPS Buildings 39 and 41)

29 U-Values Window U-value = Frame U x % Frame Area + Center of Glass U x % Glass Area + Edge of Glass U x % Edge of Glass Area U-value = 1/R-value

30 Why do We Use U-Values for Windows? Window Frame Material Aluminum Small Thermal Break Typical U-value Aluminum 0.39 Improved Thermal Break Insulated Vinyl or Fiberglass Typical R-value % Heat Flow through Framing % % % Because thermal performance is so poor?

31 Spandrel Panels Spandrels are poor thermal performers Thermal bridging of insulation by frames Effective R-value of spandrel panel assemblies are only slightly better than the windows themselves

32 U-Values What do we need? Current project original window sill detail

33 U-Values What do we need? Glazing = 0.24 Glazing + Frame = 0.37 Glazing + Frame + Flashing = 0.52 BC Energy Efficiency Act Requirement = 0.35 Building Design Requirement = 0.27

34 Shop Drawing Resubmission U value =? Moisture Management? IGU Durability?

35 Determining Thermals Resistance of Assemblies Model building in Google SketchUp Concrete Wall at Outside Corner Wall Full Height at Window Jamb Concrete Wall at Inside Corner Wall Under Window Concrete Wall Full Height Wall Full Height

36 Building 39 Typical Newer High-rise Enclosure Thermal Performance Effective Window R- value Effective Wall Area R- value Effective Roof R-value Enclosure R-value Pre Rehabilitation R- value hr ft 2 F/Btu (m 2 K/W) 1.58 (0.28) 2.95 (0.52) (3.74) 2.06 (0.36) Enclosure R-value from energy consumption data 2.2

37 ASHRAE Compliance Prescriptive Path ASHRAE Compliance - Influence of Window Framing Type & IGU on Overall Enclosure R-value Overall Combined Wall and Win ndow Enclosure R-value Compliant Enclosure Walls effective R-15.6, exterior insulated,clip supports, minimal exposed slab edges Non-Compliant Enclosure <R-3.75 R2.06 < R3.75 0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100% % Window Area Arranged in order from best to worst U-value Vinyl/Wood/Fiberglass - lowe/argon Triple IGUs, U-0.17 Vinyl/Wood/Fiberglass - lowe/argon Double IGUs, U-0.27 High Perf. Aluminum - lowe/argon Triple IGUs, U-0.29 High Perf. Aluminum - lowe/argon Double IGUs, U-0.39 High Perf. Aluminum - lowe/air Double IGUs, U-0.43 Typical Aluminum - low-e/air Double IGUs, U-0.49 Minimum ASHRAE Compliant, U-0.55 U-values from ASHRAE tables & NFRC published values

38 Building 19 Pre & Post Rehabilitation R-values Building #19 Pre and Post R-value Improvement Pre Rehabilitation Post Rehabilitation Assembly Description R-value Assembly Description R-value Walls (52%( of enclosure): Walls: Steel Stud w/ R-14 fiberglass. Exterior insulated, R-9.5 mineral Slab edges un-insulated, wool between steel z-girts. No 3.9 balconies stud cavity insulation. Slab 5.3 edge insulated, balconies uninsulated. Windows ( 27% of enclosure, Windows: 34% of wall area): High performance thermally Non-thermally broken broken aluminum frames. Soft aluminum frames. Clear glass, coat low-e, air filled IGUs with 2.16 air filled IGUs with aluminum aluminum spacers spacers Roof (21% of enclosure): Inverted assemblies with Roof: Inverted assemblies with extruded polystyrene extruded polystyrene. Overall l Building 2.92 Overall Building 4.26 Rehabilitation improved R-value by 46% (31% reduction in U-value) Rehabilitation Resulted in a Space-Heat Savings of Approximately 10%

39 Detailed R-value Calculations Pre- & Post-Rehabilitation R-values to assess space-heat savings Calculated U-values for every detail of each wall, roof, window assembly Calculated area-weighted U-values using detailed areas from sketch-up PRE R-2.92 POST R-4.26

40 Typical Enclosure R-values Study MURBs Pre-Rehabilitation Post-Rehabilitation Overall Enclosure R-Valu ue - hr ft 2 F/Btu Building ID

41 Typical Building R-value / Glazing Percentages R-16 ASHRAE prescriptive minimum R- value wall 14 Overall Enc clsosure R-value R-10 Exterior insulated wall with no balconies & minimal thermal bridging R-5 Typical practice accounting for thermal bridging Typical MURB Enclosure R-value R-2 to R-5 0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100% % Window and Door Area R-2.5 High Performance Aluminum Windows R-1.3 Low Performance Aluminum Windows

42 Whole Building Modeling

43 Whole Building Energy Simulation FAST Facility Analysis and Simulation Tool (FAST) Developed by EnerSys Analytics Uses DOE-2 engine (same engine as equest, EE4) Customized for Multi-Unit Residential Buildings

44 Whole Building Energy Simulation FAST Define building through series of inputs Architectural Mechanical Space conditions

45 Whole Building Energy Simulation FAST Program calculates monthly gas and electricity consumption

46 Whole Building Energy Simulation FAST Model calibrations Define set of starting estimates for unknown input parameters Run simulation, compare simulation output to metered energy consumption (from bills) Adjust unknown inputs so that simulation output matches metered consumption

47 Whole Building Energy Simulation FAST Eg. Building 32: Suite Electricity Decreased space heating (lowered baseboard capacity) to calibrate simulation to metered data Uncalibrated Energy in kwh 250, ,000 Difference 20% 15% 10% Avg. Monthly Error: 35.4% 9.7% Ann. Error: 46.2% 150,000 5% 0% 100,000-5% Billed 50,000-10% -15% Simulated Difference 0-20% Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Calibrated Energy in kwh 140, , ,000 80,000 60,000 40,000 20,000 Difference 20% 15% 10% 5% 0% -5% -10% -15% Avg. Monthly Error:.0% 2.7% Ann. Error:.1% Billed Simulated Difference 0-20% Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

48 Whole Building Modeling, Building 33 Energy in kwh 300, , , , ,000 50,000 0 Difference Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 20% 15% 10% 5% 0% -5% -10% -15% -20% Un-calibrated results (45.1% annual difference) Avg. Monthly Error: 35.5% 8.3% Ann. Error: 45.1% Billed Simulated Difference Energy in kwh 160,000 Difference 20% 140,000 15% 120,000 10% 100,000 5% 80,000 0% 60,000-5% 40,000-10% 20,000-15% 0-20% Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Calibrated results (o.1 % annual difference) Avg. Monthly Error:.1% 2.9% Ann. Error:.1% Billed Simulated Difference

49 Building 33 Modeling, Gas Consumption Natural Gas in GJ Difference Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 20% 15% 10% 5% 0% -5% -10% -15% -20% Un-calibrated results (24.1% annual difference) Avg. Monthly Error: 24.9%.8% Ann. Error: 24.1% Billed Simulated Difference 700 Natural Gas Difference Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Calibrated results (o.8 % annual difference) 20% 15% 10% 5% 0% -5% -10% -15% -20% Avg. Monthly Error: -.6% 1.2% Ann. Error:.8% Billed Simulated Difference

50 Distribution of Energy Consumption Building 33 Total building energy consumption = kwh/m 2 /yr Equipment and Ammenity (Common), 28.3, 14% Elevators, 4.2, 2% Electric Baseboard Heating, 18.8, 9% Plug and Appliances (Suites), 18.7, 9% Fireplaces, 37.2, 19% Lights - Suite, 15.9, 8% Lights - Common, 3.7, 2% DHW, 32.9, 17% Ventilation Heating, 39.7, 20%

51 Distribution of Energy Consumption - Modern MURB Equipment and Ammenity (Common), 19.9, 9% Elevators, 2.7, 1% Electric Baseboard Heating, 29.1, 13% Plug and Appliances (Suites), 18.7, 9% Fireplaces, 24.1, 11% Lights -Suite, 15.9, 7% Lights -Common, 3.8, 2% Heat DHW, 20.7, 9% Modern MURB - >221.9 kwh/m 2 Ventilation Heating, 86.9, 39%

52 Impact of Nominal R-Values In Modeling Building 11 Annual Space Heat Consu umption, kwh/m Baseline Pre Nominal Assumptions 29 % Difference in Space Heat Energy Consumption

53 Other Building Systems Calibrated models allow the assessment of other building systems Number of Su uites Buildings 7, 11, 32, 33 Building Peak Average Daily Domestic Hot Water Consumption, gpm Domestic Hot Water

54 Other Building Systems Power Density (W/sf) Suite Lighting Suite Plug Loads Building Number Suite Lighting and Plug Loads

55 Typical Building Model Created a typical building model to run simulations Typical Building Model Based on 13 Buildings Average of 39 Study Buildings Total Floor Area 121,922 ft² 118,655 Percent Area for Common Space 13% Number of Suites Number of Storeys (above grade) Height of Average Storey 8.7 ft Orientation from North 0 o Gross Exposed Wall Area, Wall ft² Gross Exposed Wall Area, Wall ft² Gross Exposed Wall Area, Wall ft² Gross Exposed Wall Area, Wall ft² Window Percentage, Wall 1 46% 47% Window Percentage, Wall 2 46% 47% Window Percentage, Wall 3 46% 47% Window Percentage, Wall 4 46% 47% Infiltration Rate (0.15 cfm/sf) ACH Pre Post Overall Roof R-Value o F-ft²-hr/Btu Overall Wall R-Value o F-ft²-hr/Btu Overall Window U-Value Btu/ o F-ft²-hr Window Solar Heat Gain Coefficient Architectural Inputs

56 Distribution of Energy Consumption Typical MURB uses approximately 200 kwh/m 2 /yr Equipment and Ammenity (Common), 28.3, 14% Elevators, 4.2, 2% Electric Baseboard Heating, 18.8, 9% Plug and Appliances (Suites), 18.7, 9% Fireplaces, 37.2, 19% Lights - Suite, 15.9, 8% Lights - Common, 3.7, 2% DHW, 32.9, 17% Ventilation Heating, 39.7, 20%

57 Space Heat Consumption for locations across Canada 180 Annual Space Hea at Consumption, kwh/m Ottawa Vancouver Calgary Edmonton Winnipeg Toronto Ottawa Montreal Halifax Whitehorse

58 Impact of Wall Performance on Space Heat Consumption

59 Window Influence on Total Building Energy Comparison of Different Window Performance Criteria on Total Building Energy Consumption Case Baseline Performance Standard (effective values) Average Pre Wall R-3.6 Roof R-12.7 Overall Product Performance Characteristics [W/(m 2 K] Total Heating [kwh/m 2 ] Total Bldg Energy [kwh/m 2 ] % Total Savings U-3.97, SHGC % Window U-3.97 SHGC-0.67 Window ASHRAE U-3.24, SHGC % ASHRAE U-3.1, SHGC % ASHRAE U-2.57, SHGC % BC EEA metal frame U-2.57, SHGC % BC EEA non-metal frame U-2.0, SHGC % Non-metal frame, low-e, U-0.96, SHGC % argon fill, triple glazed Lighting ASHRAE W/m % ASHRAE W/m %

60 Impact of Window Performance on Space Heat 120 Annual Space Heat Consumption, kwh/m Electricity Gas 0 Baseline U = 0.45 SHGC = 0.4 U = 0.45 SHGC = 0.3 U = 0.27 SHGC = 0.4 U = 0.27 SHGC = 0.3 U = 0.17 SHGC = 0.3 U = 0.17 SHGC = 0.2 Post U-Value with Pre SHGC

61 Air Flow

62 Space Heat Loss Distribution Effect of Air Leakage Air Tight Enclosure Natural Air Leakage, 2.9, 3% Air Leaky Enclosure Open Windows Natural Air Leakage, 16.3, 16% Conduction, 47.9, 53% Mechanical Ventilation, 39.7, 44% Conduction, 47.9, 46% Mechanical Ventilation, 39.7, 38% kwh/m 2 /yr, % Total Space Heat Total Space Heat = 90.5 kwh/m 2 /yr kwh/m 2 /yr, % Total Space Heat Total Space Heat = kwh/m 2 /yr

63 What if Good Enclosure & w/heat Recovery Ventilation? Air Tight Enclosure Air Leaky Enclosure Open Windows Conduction 5% Conduction, 2.3, 20% Natural Air Leakage, 2.5, 22% Mechanical Ventilation 24% Mechanical Ventilation, 6.5, 58% Natural Air Leakage 71% kwh/m 2 /yr, % Total Space Heat Total Space Heat = 11.2 kwh/m 2 /yr kwh/m 2 /yr, % Total Space Heat Total Space Heat = 30.3 kwh/m 2 /yr

64 Impact of Different Make-up Air Flow Rates Assumed flow rate of 50 cfm per suite 160 Annual Space Heat Cons sumption, kwh/m Gas 0 100% of Nominal* 95% of Nominal 90% of Nominal 85% of Nominal 80% of Nominal 75% of Nominal 70% of Nominal 65% of Nominal 60% of Nominal Zero Modern

65 Understanding Energy Use in MURBs Domestic Hot Water is heated using Gas Air leakage of heated ventilation air through elevator and stairwell shafts Elevator pumping Ventilation air is heated using gas-fired make-up air unit (MUA) - To heat ventilation air for make-up air supply - To heat domestic hot water - To heat pool/hot-tubs - Suite fireplaces (if equipped) - Pilot lights for above - Interior lighting - Elevators - Ventilation fans and motors - Parking garage exhaust fans - Water distribution pumps - Baseboard heaters - Recreation areas/pool pumps - Exterior lighting - Communication - Controls Heated Ventilation air from corridor Electric Baseboard Heaters in all Suites Gas fireplaces in some Suites Air flow through open windows Air exhausted using bathroom/kitchen fans & windows Enclosure airleakage - Baseboard heaters - Lighting - Appliances - Miscellaneous Electric Loads - Plug loads - Exhaust fans Gas Boiler to heat pool & hot-tubs Rec. Areas Pool Suites Common Areas Parking Garage Typically Unheated Some Gas & Electric Heat at Common Areas Parking Garage Exhaust Fans

66 Air Flow within a Building Building 20

67 Air Pressure Differential in Study Building (43) 22 storey highrise - Pressure Beneath Suite Doors Floor Theoretical 18 Average 17 Maximum 16 Linear (Theoretical) 15 Linear (Average) Linear (Maximum) Pressure Differential (Pa) Measured air pressure across the corridor doors of suites in a 22 storey building

68 Make-Up air Considerations 1. We should be ventilating for health and comfort (not heat) 2. Corridors need a minimal amount of air for smoke/odour control but fresh air is needed in the suites. 3. Reconsider large rooftop MUA units & pressurized corridor supply for ventilation. 4. Provide fresh air-directly to suites 5. Compartmentalization is needed Further research of air flow within buildings required

69 Make-Up Air Investigation Investigation and analysis of condensation related problems at window-wall assemblies. Monitored environmental conditions and mechanical system conditions: Temperatures Relative Humidity CO 2 Operation of mechanical equipment including Heat pump Cloths dryer Exhaust Fans Make-up air at suite door

70 Make-Up Air Investigation

71 Actual Airflow Suite Number N601 N301 Baseline (no fans operational) Master Bathroom Fan Guest Bathroom Fan Common Bathroom Fan Kitchen Fan - Level 1 Kitchen Fan - Level 2 Kitchen Fan - Level 3 Dryer w/ Booster Fan ASHRAE Recommended (based on suite size = 0.3 ACH) % of ASHRAE Baseline % of ASHRAE Recommended with Continuous Master Bath Fan ASHRAE Recommended (based on # of occupants, 15cfm/person) % of ASHRAE Baseline % of ASHRAE Recommended with Continuous Master Bath Fan Control suite Air flow less affected by fan operation, hallway pressurization was not working ASHRAE recommendations based on suite area (accounts for 5-6 occupants) ASHRAE recommendations at 15 cfm per person for actual occupant loads 24 cfm cfm 29% 67% 30 cfm 79% 183% 0 cfm cfm 0% 10% 30 cfm 0% 27%

72 Other Considerations Fireplaces Occupants etc.

73 Other Considerations Impact of Fireplaces Why do we need them? 120 Annual Space Heat Cons nsumption, kwh/m Gas Electricity Baseline Pre With Fireplaces Baseline Pre Without Fireplaces

74 Distribution of Energy Costs in MURBs Plug and Appliances (Suite), 18.7, 31% Electric Baseboard Heating, 24.8, 42% Total Consumed By Strata, 146.9, 71% Total Consumed By Owner, 59.5, 29% Equipment and Ammenity (Common), 28.3, 19% Lights (Suite), 15.9, 27% Elevators, 4.2, 3% Owner Paid Electric Baseboard Heating, 0.3, 0% Fireplaces, 37.7, 26% Lights (Common), 3.7, 3% Strata Paid DHW, 32.9, 22% Ventilation Heating, 39.7, 27%

75 Disconnect Between Consumption and Billing Average MURB Energy Distribution and Associated Cost 28% Suite Electricity = $408/yr (Occupant Paid) 21% Common Area Electricity = $323/yr (Strata Paid) 51% Gas Heat and Hot water = $455/yr (Strata Paid) Only 36% of Total Energy Cost is Directly Paid by Occupant 69% of Building Space Heat is from Gas (Paid by Strata) Occupants are only directly paying for 31% of space heating

76 How Do We Do Better?

77 Where Do We Want To Go? New Buildings to be Carbon Neutral by 2020 Biggest Opportunities in Existing Buildings

78 Getting to Best Performance Space Heating Reduce the loads Recover the heat

79 Impact of Cladding Attachment R-15 of Insulation Current Practice Better Even Better Most Efficient R-7.4 R-10.3 R-11.6 to 14.4 R-15.8

80 Retrofit and New Construction Enclosure Strategies 10 ASHRAE Compliance - Influence of Window Framing Type on Overall Enclosure R-value 9 Overall Combined Wall and Wind dow Enclosure R-value ASHRAE Compliant Buildings Constructed with minimally compliant wall and window R-values Study Buildings - Metro Vancouver Average 50% glazing area Thermally Efficient Building Enclosures Constructed with high performance windows and well insulated walls 0 0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100% % Window Area

81 Thermal Anatomy of a High Rise MURB R-12 Insulation in walls R-4 accounting for steel studs and slab edges R-1.8 Windows aluminum window wall, low-e, air fill R-20 Roof Insulation 65% Glazing R-Value % of Enclosure % Heat loss Walls Windows Roof Overall R-Value 2.3 Strategy 1 Improve wall R-value to R10 Strategy 2 Improve window R-value to R3.5 Strategy 3 Reduce window area to 30%

82 Strategy 1 Improve wall R-value to R10 R-Value % of Enclosure % Heat loss Walls Windows Roof Overall R-Value Base Strategy 1

83 Strategy 2 Improve Window R-value to R3.5 R-Value % of Enclosure % Heat loss Walls Windows Roof Overall R-Value Base Strategy 1 Strategy 2

84 Strategy 3 Reduce Glazing to 30% R-Value % of Enclosure % Heat loss Walls Windows Roof Overall R-Value Base Strategy 1 Strategy 2 Strategy 3

85 Reduced Glazing Area

86 Improved Ventilation Strategies Corridor pressurized with small fans at each floor level

87 Combination Energy Efficiency Measures Simulated Scenario Model Inputs Baseline Post t Walls effective R-5.5 t Windows double glazed, air fill, low-e, aluminum frame; U = 0.51, SC = 0.45 t Air tightness Tight High Average, 0.15 cfm/ft 2 t Make-up air temperature setpoint 68 F t No heat recovery Good t Walls effective R-10 t Windows double glazed, argon fill, low-e, low conductive frame; U = 0.27, SC = 0.35 t Air tightness Tight Low Average, 0.05 cfm/ft 2 t Make-up air temperature setpoint 64 F t No heat recovery Best t Walls effective R-18.2 t Windows triple glazed, argon fill, low-e, low conductive frame; U = 0.17, SC = 0.23 t Air tightness Very Tight, 0.02 cfm/ft 2 t Make-up air temperature setpoint 60 F t 80% Heat Recovery

88 Simulated Space Heat Consumption Scenarios Annual Space Heat Cons sumption, kwh/m Better windows, walls and air-tightness 67.4 Ventilation Heat-Recovery Baseline Pre Baseline Post Good Best Good, Without Fireplaces Best, Without Fireplaces

89 Total Building Energy Use Can get ~100 kwh/m 2 /yr with ventilation and enclosure upgrades only Further improvements from Domestic Hot Water, Lighting, Appliances, Controls etc. 250 Annual Energy Consumption, kwh/m Gas Electricity 0 Baseline Pre Baseline Post Good Best Good, Without Fireplaces Best, Without Fireplaces

90 How Do We Get To Net Zero? 35 R-Values 30 t Consumption, kwh/m 2 Annual Suite Electric Space Heat U = 0.45, 50% WWR U = 0.45, 40% WWR U = 0.45, 30% WWR U = 0.45, 20% WWR U = 0.27, 50% WWR U = 0.27, 40% WWR U = 0.27, 30% WWR U = 0.27, 20% WWR U = 0.17, 50% WWR U = 0.17, 40% WWR U = 0.17, 30% WWR U = 0.17, 20% WWR Wall Effective R-Value R (hr-ft 2 -F/Btu)

91 Near Net Zero Effective Control of Air Flow 40 Annual Suite Electric Space Heat Consumption, kwh/m Enclosure 1: Windows U-0.17, 30% WWR, Walls R-18.2 Enclosure 2: Windows U-0.45, 40% WWR, Walls R-15.6 Typical Building Simulated Air Leakage Rate Air Leakage Rate, cfm/sf

92 Final Thoughts - Energy Efficiency & Moisture Problems Increased risk of moisture problems in more energy efficient buildings Consider future maintenance and renewal costs Systemic Low-e corrosion within proprietary triple IGUs after 5 years Failure of thermo-cladding

93 Need for a New Approach

94 Integrated Design Process Courtesy of Bunting Coady Architects

95 A New Approach for the Design of Buildings

96 A New Approach for the Design of Buildings

97 A New Approach for the Design of Buildings

98 A New Approach for the Design of Buildings

99 Discussion

100 Further Information / Background Information CMHC Reports / Guides Homeowner Protection Office Bulletins and Guides Builder Insight No. 7 Building Enclosure Design Guide

101 BC Energy Efficiency Act - Windows Low-rise Requirements Product Maximum U-Value W/(m 2 K) BTU/(hr ft 2 K) Effective Date Vinyl and fibreglass windows and sliding doors Tested with CSA A or NFRC Third party testing (SCC or NFRC accredited labs) Permanent certification label, temporary U-value label Exempts heritage buildings March 1, 2009 Wood windows and sliding glass doors January 1, 2011 Metal windows and sliding glass doors June 1, 2009 January 1, 2011 Skylights (for low-rise and high-rise) March 1, 2009

102 BC Energy Efficiency Act - Windows High-rise Requirements Product Maximum U-Value W/(m 2 K) BTU/(hr ft 2 K) Effective Date Metal framed curtain wall, window wall and storefront products Windows with framing materials other than metal, with or without metal reinforcing or cladding January 1, January 1, 2011 Exempts products installed in buildings that are compliant with ASHRAE 90.1 (04 or 07) Option for U-value certificate in lieu of labels Flexibility provided for structural windows

103 Improved Ventilation Strategies Corridor pressurized with small fans at each floor level

104 Questions?