Energy Consumption in Mid-and High-rise Residential Buildings · Understanding of: Learning...
Transcript of Energy Consumption in Mid-and High-rise Residential Buildings · Understanding of: Learning...
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
Understanding of:
Learning Objectives
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.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 90.1.
How to improve performance characteristics of building enclosure assemblies.
By 2020:
33 % reduction in Greenhouse Gas Emissions
Energy Efficient Building Strategy
BC Climate Action Plan
-20% energy use per household
Clean Energy Act
2020 Goals:
Carbon Neutral New Buildings
20% Reduction in Energy Consumption and Greenhouse Gas Emissions in Existing Buildings
City of Vancouver – Greenest City Action Plan
Buildings account for 55% of Greenhouse Gas EmissionsBuildings account for 55% of Greenhouse Gas Emissions
How will we get there?
Absolute Energy Intensity requirements (kwh/m2/yr)
Incentives and other means
Multi-Unit High-Rise Residential Building Energy Study
Energy consumption of over 60 mid- to high-rise 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
CMHC SCHL
Allows for the assessment of actual energy savings from enclosure performance
Pre- and post-rehabilitation R-values, air-tightness characteristics are compared to energy consumption.
Other building performance characteristics as a result of the enclosure improvements are assessed.
Energy Units
Typical energy intensity units - kWh/m2/yr or GJ/m2/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 = 277.8 kWh (or ekWh) 1 GJ = 277.8 kWh (or ekWh)
Why High-rise MURBs?
55% of GHGs from Buildings in Vancouver
High-rise MURBs largest emitters (COV)
Not well understood
Study Buildings
39 mid and high rise residential buildings
4,400 residential suites
4,600,000 square feet of floor area
Study Buildings
$5,000,000 annual energy costs
44,000,000 kWh annual electricity use
173,000 GJ annual gas use
Design Characteristics – Older Buildings
Lower glazing percentage
Framed walls
Exposed concrete
Punched windows
Design Characteristics – 1990s Buildings
Higher glazing percentage
Concrete walls
Framed wall
Window wall and punched windows
High glazing percentage
Metal panel cladding
Concrete fins
Window wall / spandrel panels
Design Characteristics - More Recent Buildings
Top down:
Annual bulk energy billed known
Suggests good overview
Problems:
Metering varies (individual for electrical, vs. common for gas)
Building features and activities
Top-down vs. Bottom-up Analysis
Building features and activities
• Pools, elevators, fireplaces, lighting, etc.
Seasonal conversion efficiencies not known
Bottom-up:
Detailed information available
Can identify anomalies or errors in billing data
One building at a time
Building systems known
Modeling software available
Better weather data (smart metering data during cold rain events)
Occupant Behavior?
Monthly Energy Consumption – Typical Building
kWh
Baseline Suite Electricity – No Space Heat
Baseline Gas – No Space Heat
Estimated Monthly Heating
kWh
Energy Intensity kWh/m2/yr
200
250
300
350Common Electricity
Suite Electricity
Gas
Average = 213 kWh/m2/yr
Median = 217 kWh/m2/yr
Std Dev = 42 kWh/m2/yr
Range = 144 to 299 kWh/m2/yr
Average = 213 kWh/m2/yr
-
50
100
150
200
81
14
4 95
24
26
16
31
8 76
21
22
61
93
33
22
04
52
91
74
36
03
12
8 61
4 33
9 25
73
04
12
4 14
05
92
13
65
8
Distribution of Space Heat Energy
% of Total Building Energy Used for Space Heat% of Total Building Energy Used for Space Heat% of Total Building Energy Used for Space Heat% of Total Building Energy Used for Space Heat
40%
50%
60%
% Total Energy Which is Heat
Electrical Heat
Gas Heat
Average 37% of total building energy is
used for heat
Of this portion an average of 69% of
this energy is from gas
Average of 37% of Energy is used for Space-Heating
0%
10%
20%
30%
26 18 11 6 157 2 743 21
32 61
52 14 2459 44 17 29 42
4030 3141
202862 45
60 33 19 36 58 12 39 3 863 9
Building ID
% Total Energy Which is Heat
Energy Consumption vs Year of Construction
200
250
300
350
Energ
y C
onsu
mpti
on - k
Wh
/m2/y
r
Total Energy
Space Heat Energy
-
50
100
150
200
19
72
19
74
19
76
19
78
19
80
19
82
19
84
19
86
19
88
19
90
19
92
19
94
19
96
19
98
20
00
20
02
20
04
Year of Construction
Energ
y C
onsu
mpti
on - k
Wh
/m
Fuel for Space Heat versus Age of Building
100
120
140
160
Gas MAU or Fireplace Space Heat
Electric Resistance Space Heat
Electric Space Heat Trend
Gas Space Heat Trend
kWh/m2/yr
-
20
40
60
80
19
74
19
75
19
81
19
84
19
85
19
85
19
85
19
86
19
87
19
89
19
90
19
90
19
90
19
90
19
92
19
92
19
92
19
93
19
93
19
93
19
94
19
94
19
94
19
94
19
94
19
95
19
95
19
95
19
95
19
95
19
96
19
96
19
96
19
97
19
97
20
01
20
01
20
02
20
02
% Total Building Heat which is Gas
60%
80%
100%
% S
pace
Heat fr
om
Gas
Average of 69%, Majority of Space-Heat
Energy from Gas Sources
Hydronic Gas Heat
MURBs with fireplaces in
majority of suites
Space-Heat from Gas Sources
0%
20%
40%
60%
11
42
62
61
44 6
18
17
43 7
28
40
29
32 1 2
57
26 8
33
14
31 3
59
30
52
63
60 9
20
39
12
24
41
21
58
45
36
19
% S
pace
Heat fr
om
Gas
Current Misconceptions about High-Rise Energy Use
258 kWh/m2
128 kWh/m2
Actual ?>213 kWh/m2
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
Detailed Analysis
Heat Transfer
Model assemblies using THERM 5.2
Determining Thermals Resistance of Assemblies
Isothermal planes modeling technique
Three-Dimensional Components
Steel Stud
Interior Gypsum Wall Board Exterior Insulation
(Mineral Wool)
Cladding (Stucco)
Stud Sill Track
Stud Head Track
Concrete Floor Slab
Exterior Sheathing
Steel Z-girts
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.
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.
Horizontal Cross-section Vertical Cross Section
Verify with HEAT 3D and previous Guarded Hot-Box testing results
Three-Dimensional Components
HEAT 3D model of 6” Stainless Steel Clip
Temperature Isotherms for 6” Stainless Steel Clip
Temperature Isotherms through stainless clip –horizontal cut
R-Values
Down Jacket
R 3-5
Acoustic Ceiling Tile
R 2
3.5’’ Fibreglass
Framed Wall with Batt Insulation
Steel stud wall assembly with concrete slab
R 12 or R14
R 3 - 4
3’’ XPS Insulation
Exterior Insulated Wall
Exterior insulated wall assembly
R 15
R 7.5
1’’ XPS Insulation
R5
Concrete Wall
Concrete wall with steel stud furring
R 7(R3 without XPS – Buildings 39 and 41)
3.5’’ Fibreglass
R14
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
Why do We Use U-Values for Windows?
Window Frame Material
Typical U-value
Typical R-value
% Heat Flow through Framing
Aluminum –
Small Thermal Break
0.550.550.550.55 1.821.821.821.82 60%60%60%60%
Aluminum – 0.390.390.390.39 2.582.582.582.58 45%45%45%45%
Because thermal performance is so poor?
Improved Thermal Break
0.390.390.390.39 2.582.582.582.58 45%45%45%45%
Insulated Vinyl or Fiberglass
0.270.270.270.27 3.73.73.73.7 23%23%23%23%
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
Current project – original window sill detail
U-Values – What do we need?
Glazing = 0.24
U-Values – What do we need?
Glazing + Frame
= 0.37
Glazing + FrameGlazing + Frame+ Flashing
= 0.52
BC Energy Efficiency Act Requirement = 0.35
Building Design Requirement = 0.27
Shop Drawing Resubmission
U value = ?
Moisture Management ?
IGU Durability?
Model building in Google SketchUp
Determining Thermals Resistance of Assemblies
Wall Full Height at Window JambConcrete Wall at Outside Corner Wall Full Height at Window Jamb
Wall Under Window
Wall Full Height
Concrete Wall at Outside Corner
Concrete Wall at Inside Corner
Concrete Wall Full Height
Building 39 – Typical Newer High-rise
Enclosure Thermal Enclosure Thermal Enclosure Thermal Enclosure Thermal PerformancePerformancePerformancePerformance
Pre Rehabilitation RPre Rehabilitation RPre Rehabilitation RPre Rehabilitation R----valuevaluevaluevalue
hr fthr fthr fthr ft2222 F/BtuF/BtuF/BtuF/Btu
(m(m(m(m2222 K/W)K/W)K/W)K/W)
Effective Window R-value
1.58
(0.28)
Effective Wall Area R-value
2.95
(0.52)
Effective Roof R-value21.25(3.74)
Enclosure REnclosure REnclosure REnclosure R----valuevaluevaluevalue2.06(0.36)(0.36)(0.36)(0.36)
Enclosure R-value from energy consumption data 2.2
ASHRAE 90.1-2007 Compliance – Prescriptive Path
9
10
11
12
13
14
15
16
Overall Combined Wall and Window Enclosure R-value
Vinyl/Wood/Fiberglass - low-e/argon Triple IGUs, U-0.17
Vinyl/Wood/Fiberglass - low-e/argon Double IGUs, U-0.27
High Perf. Aluminum - low-
ASHRAE 90.1-2007 Compliance - Influence of Window Framing Type & IGU on Overall Enclosure R-value
Walls effective R-15.6, exterior insulated,clip
supports, minimal exposed slab edges
Arranged in order from
best to worst U-value
R2.06 < R3.75
0
1
2
3
4
5
6
7
8
9
0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%
% Window Area
Overall Combined Wall and Window Enclosure R-value
High Perf. Aluminum - low-e/argon Triple IGUs, U-0.29
High Perf. Aluminum - low-e/argon Double IGUs, U-0.39
High Perf. Aluminum - low-e/air Double IGUs, U-0.43
Typical Aluminum - low-e/airDouble IGUs, U-0.49
Minimum ASHRAE 90.1-2007Compliant, U-0.55
U-values from ASHRAE
tables & NFRC published
values
Compliant
Enclosure
Non-Compliant
Enclosure <R-3.75
Building 19 – Pre & Post Rehabilitation R-values
PrePrePrePre Rehabilitation Rehabilitation Rehabilitation Rehabilitation Post RehabilitationPost RehabilitationPost RehabilitationPost Rehabilitation Building #19 Pre and PBuilding #19 Pre and PBuilding #19 Pre and PBuilding #19 Pre and Poooost st st st RRRR----value value value value
IIIImmmmprovement provement provement provement Assembly DescriptionAssembly DescriptionAssembly DescriptionAssembly Description RRRR----vvvvaluealuealuealue Assembly Description Assembly Description Assembly Description Assembly Description RRRR----valuevaluevaluevalue
Walls (Walls (Walls (Walls (52% of enclosure)52% of enclosure)52% of enclosure)52% of enclosure)::::
Steel Stud w/ R-14 fiberglass.
Slab edges un-insulated,
balconies 3.93.93.93.9
Walls: Walls: Walls: Walls:
Exterior insulated, R-9.5 mineral
wool between steel z-girts. No
stud cavity insulation. Slab
edge insulated, balconies
uninsulated.
5.5.5.5.3333
WindowsWindowsWindowsWindows ( 27% of enclosure, ( 27% of enclosure, ( 27% of enclosure, ( 27% of enclosure, Windows:Windows:Windows:Windows:
34% of wall area)34% of wall area)34% of wall area)34% of wall area)::::
Non-thermally broken
aluminum frames. Clear glass,
air filled IGUs with aluminum
spacers
1.371.371.371.37
High performance thermally
broken aluminum frames. Soft-
coat low-e, air filled IGUs with
aluminum spacers
2.162.162.162.16
RoofRoofRoofRoof (21% of enclosure) (21% of enclosure) (21% of enclosure) (21% of enclosure)::::
Inverted assemblies with 3”
extruded polystyrene
14.14.14.14.3333
Roof:Roof:Roof:Roof:
Inverted assemblies with 4”
extruded polystyrene.
18.18.18.18.3333
OveralOveralOveralOverall Buildingl Buildingl Buildingl Building 2.922.922.922.92 Overall BuildingOverall BuildingOverall BuildingOverall Building 4.264.264.264.26
Rehabilitation improved RRehabilitation improved RRehabilitation improved RRehabilitation improved R----value by 46% (31% reduction in Uvalue by 46% (31% reduction in Uvalue by 46% (31% reduction in Uvalue by 46% (31% reduction in U----value)value)value)value)
Rehabilitation Resulted in a SpaceRehabilitation Resulted in a SpaceRehabilitation Resulted in a SpaceRehabilitation Resulted in a Space----Heat Savings of Approximately 10%Heat Savings of Approximately 10%Heat Savings of Approximately 10%Heat Savings of Approximately 10%
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
Detailed R-value Calculations
PRE R-2.92 POST R-4.26
Typical Enclosure R-values – Study MURBs
2.92.92.92.9
3.33.33.33.3
3.53.53.53.5
3.13.13.13.1
3.63.63.63.6
3.33.33.33.3
3.63.63.63.6
4.34.34.34.34.14.14.14.1
3.03.03.03.0
3.53.53.53.5
4.04.04.04.0
4.54.54.54.5
Ove
rall E
ncl
osu
re R
-Valu
e - h
r ft
Ove
rall E
ncl
osu
re R
-Valu
e - h
r ft
Ove
rall E
ncl
osu
re R
-Valu
e - h
r ft
Ove
rall E
ncl
osu
re R
-Valu
e - h
r ft
22 22 F
/Btu
F/B
tu
F
/Btu
F/B
tu
Pre-Rehabilitation
Post-Rehabilitation
2.02.02.02.0 2.02.02.02.0 2.12.12.12.12.22.22.22.2 2.22.22.22.2
2.32.32.32.3
2.72.72.72.7 2.72.72.72.7
2.92.92.92.9
2.62.62.62.6
1.01.01.01.0
1.51.51.51.5
2.02.02.02.0
2.52.52.52.5
3.03.03.03.0
39393939 41414141 62626262 33333333 20202020 32323232 18181818 17171717 19191919 7777
Building ID
Ove
rall E
ncl
osu
re R
-Valu
e - h
r ft
Ove
rall E
ncl
osu
re R
-Valu
e - h
r ft
Ove
rall E
ncl
osu
re R
-Valu
e - h
r ft
Ove
rall E
ncl
osu
re R
-Valu
e - h
r ft
Typical Building R-value / Glazing Percentages
8
10
12
14
16
Overall Enclsosure R-value
R-16 ASHRAE 90.1
prescriptive minimum R-
value wall
R-10 Exterior
insulated wall with
no balconies &
minimal thermal
bridging Typical MURB Enclosure
0
2
4
6
0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%
% Window and Door Area
Overall Enclsosure R-value
R-2.5 High Performance
Aluminum Windows
R-1.3 Low Performance
Aluminum Windows
bridging
R-5 Typical
practice accounting
for thermal bridging
Typical MURB Enclosure
R-value R-2 to R-5
Overall
Whole Building Modeling
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
Whole Building Energy Simulation – FAST
Define building through series of inputs
Architectural
Mechanical
Space conditions
Whole Building Energy Simulation – FAST
Program calculates monthly gas and electricity consumption
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
Whole Building Energy Simulation – FAST
metered consumption
Eg. Building 32: Suite Electricity
Decreased space heating (lowered baseboard capacity) to calibrate simulation to metered data
Whole Building Energy Simulation – FAST
5%
10%
15%
20%
150,000
200,000
250,000DifferenceEnergy in kWh Avg. Monthly Error:
35.4% 9.7%
Ann. Error: 46.2%Uncalibrated
-20%
-15%
-10%
-5%
0%
0
50,000
100,000
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Billed
Simulated
Difference
-20%
-15%
-10%
-5%
0%
5%
10%
15%
20%
0
20,000
40,000
60,000
80,000
100,000
120,000
140,000
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
DifferenceEnergy in kWh
Billed
Simulated
Difference
Avg. Monthly Error: .0% 2.7%
Ann. Error: .1%Calibrated
Whole Building Modeling, Building 33
-20%
-15%
-10%
-5%
0%
5%
10%
15%
20%
0
50,000
100,000
150,000
200,000
250,000
300,000
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
DifferenceEnergy in kWh
Billed
Simulated
Difference
Avg. Monthly Error: 35.5% 8.3%
Ann. Error: 45.1%
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
-20%
-15%
-10%
-5%
0%
5%
10%
15%
20%
0
20,000
40,000
60,000
80,000
100,000
120,000
140,000
160,000
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
DifferenceEnergy in kWh
Billed
Simulated
Difference
Avg. Monthly Error: .1% 2.9%
Ann. Error: .1%
Un-calibrated results (45.1% annual difference)
Calibrated results (o.1 % annual difference)
Building 33 Modeling, Gas Consumption
-20%
-15%
-10%
-5%
0%
5%
10%
15%
20%
0
100
200
300
400
500
600
700
800
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
DifferenceNatural Gas in GJ
Billed
Simulated
Difference
Avg. Monthly Error: 24.9% .8%
Ann. Error: 24.1%
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
-20%
-15%
-10%
-5%
0%
5%
10%
15%
20%
0
100
200
300
400
500
600
700
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
DifferenceNatural Gas
Billed
Simulated
Difference
Avg. Monthly Error: -.6% 1.2%
Ann. Error: .8%
Un-calibrated results (24.1% annual difference)
Calibrated results (o.8 % annual difference)
Total building energy consumption = 164.4 kWh/m2/yr
Distribution of Energy Consumption – Building 33
Electric Baseboard Heating, 18.8, 9%
Fireplaces, 37.2, 19%Plug and
Appliances
Equipment and Ammenity
(Common), 28.3, 14%
Elevators, 4.2, 2%
19%
Ventilation Heating, 39.7,
20%DHW, 32.9, 17%
Lights - Common, 3.7, 2%
Lights - Suite, 15.9, 8%
Appliances (Suites), 18.7, 9%
Distribution of Energy Consumption - Modern MURB
Electric Baseboard
Heating, 29.1, 13%
Fireplaces, 24.1, 11%
Lights - Suite, 15.9, 7%
Plug and Appliances
(Suites), 18.7, 9%
Equipment and Ammenity
(Common), 19.9, 9%Elevators, 2.7, 1%
Ventilation Heating, 86.9,
39%
DHW, 20.7, 9%
Lights - Common, 3.8, 2%
Lights - Suite, 15.9, 7%
Modern MURB Modern MURB Modern MURB Modern MURB ---- >221.9 kWh/m>221.9 kWh/m>221.9 kWh/m>221.9 kWh/m2222
Heat
Building 11
Impact of Nominal R-Values In Modeling
53.5
38.040.0
50.0
60.0
An
nu
al S
pace
Heat C
onsum
pti
on, kW
h/m
An
nu
al S
pace
Heat C
onsum
pti
on, kW
h/m
An
nu
al S
pace
Heat C
onsum
pti
on, kW
h/m
An
nu
al S
pace
Heat C
onsum
pti
on, kW
h/m
22 22
0.0
10.0
20.0
30.0
Baseline Pre Nominal Assumptions
An
nu
al S
pace
Heat C
onsum
pti
on, kW
h/m
An
nu
al S
pace
Heat C
onsum
pti
on, kW
h/m
An
nu
al S
pace
Heat C
onsum
pti
on, kW
h/m
An
nu
al S
pace
Heat C
onsum
pti
on, kW
h/m
29 % Difference in Space Heat Energy Consumption
Calibrated models allow the assessment of other building systems
Other Building Systems
120
140
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180
200
Nu
mb
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Nu
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Nu
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Buildings 7, 11, 32, 33
Building 18
0
20
40
60
80
100
120
0.00 2.00 4.00 6.00 8.00 10.00 12.00 14.00 16.00
Nu
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Peak Average Daily Domestic Hot Water Consumption, gpmPeak Average Daily Domestic Hot Water Consumption, gpmPeak Average Daily Domestic Hot Water Consumption, gpmPeak Average Daily Domestic Hot Water Consumption, gpm
Domestic Hot Water
Other Building Systems
0.40
0.50
0.60
0.70
0.80
0.90
1.00
Po
wer
Densi
ty (W
/sf)
Po
wer
Densi
ty (W
/sf)
Po
wer
Densi
ty (W
/sf)
Po
wer
Densi
ty (W
/sf)
Suite Lighting
Suite Lighting and Plug Loads
0.00
0.10
0.20
0.30
0.40
0 10 20 30 40 50 60 70
Po
wer
Densi
ty (W
/sf)
Po
wer
Densi
ty (W
/sf)
Po
wer
Densi
ty (W
/sf)
Po
wer
Densi
ty (W
/sf)
Building NumberBuilding NumberBuilding NumberBuilding Number
Suite Plug Loads
Created a typical building model to run simulations
Typical Building Model
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 110 113
Number of Storeys (above grade) 18 18
Height of Average Storey 8.7 ft
Orientation from North 0 o
Gross Exposed Wall Area, Wall 1 15580 ft² Gross Exposed Wall Area, Wall 1 15580 ft²
Gross Exposed Wall Area, Wall 2 15580 ft²
Gross Exposed Wall Area, Wall 3 15580 ft²
Gross Exposed Wall Area, Wall 4 15580 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) 0.572 ACH
Pre Post
Overall Roof R-Value 12.7 13.3 oF-ft²-hr/Btu
Overall Wall R-Value 3.6 5.5 oF-ft²-hr/Btu
Overall Window U-Value 0.70 0.51 Btu/oF-ft²-hr
Window Solar Heat Gain Coefficient 0.67 0.39
Architectural Inputs
Typical MURB uses approximately 200 kWh/m2/yr
Distribution of Energy Consumption
Electric Baseboard Heating, 18.8, 9%
Fireplaces, 37.2, 19%Plug and
Appliances
Equipment and Ammenity
(Common), 28.3, 14%
Elevators, 4.2, 2%
19%
Ventilation Heating, 39.7,
20%DHW, 32.9, 17%
Lights - Common, 3.7, 2%
Lights - Suite, 15.9, 8%
Appliances (Suites), 18.7, 9%
Space Heat Consumption for locations across Canada
102.4
131.5
140.5144.8
120.9
129.1 129.4124.4
159.9
80
100
120
140
160
180
An
nu
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on, kW
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Heat C
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22 22
0
20
40
60
80
Vancouver Calgary Edmonton Winnipeg Toronto Ottawa Montreal Halifax Whitehorse
An
nu
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pace
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onsum
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An
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pace
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onsum
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on, kW
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An
nu
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pace
Heat C
onsum
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on, kW
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An
nu
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pace
Heat C
onsum
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on, kW
h/m
Ottawa
Impact of Wall Performance on Space Heat Consumption
Window Influence on Total Building Energy
CoCoCoComparison of Different Window Performance Criteria on Total Building Energy Consumptionmparison of Different Window Performance Criteria on Total Building Energy Consumptionmparison of Different Window Performance Criteria on Total Building Energy Consumptionmparison of Different Window Performance Criteria on Total Building Energy Consumption
CaseCaseCaseCase Performance StandardPerformance StandardPerformance StandardPerformance Standard
(effective values)(effective values)(effective values)(effective values)
Overall Product Performance Overall Product Performance Overall Product Performance Overall Product Performance
CharacteristicsCharacteristicsCharacteristicsCharacteristics [W/(m[W/(m[W/(m[W/(m2222K]K]K]K]
Total Total Total Total
Heating Heating Heating Heating [kWh/m[kWh/m[kWh/m[kWh/m2222]]]]
Total Bldg Energy Total Bldg Energy Total Bldg Energy Total Bldg Energy
[kWh/m[kWh/m[kWh/m[kWh/m2222]]]]
% Total % Total % Total % Total
SavingsSavingsSavingsSavings
Baseline Average Pre Wall R-3.6
Roof R-12.7 Window U-3.97
U-3.97, SHGC-0.67 83.2 187.1 0.0%
Window U-3.97 SHGC-0.67
Window ASHRAE 90.1-2004 U-3.24, SHGC-0.4 83.3 187.2 -0.1%
ASHRAE 90.1-2007 U-3.1, SHGC-0.4 82.7 186.6 0.3%
ASHRAE 189.1-2009 U-2.57, SHGC-0.4 79.1 183.0 2.2%
BC EEA metal frame U-2.57, SHGC-0.4 79.1 183.0 2.2%
BC EEA non-metal frame U-2.0, SHGC-0.4 75.0 178.8 4.4%
Non-metal frame, low-e, argon fill, triple glazed
U-0.96, SHGC-0.3 67.6 171.5 8.4%
Lighting ASHRAE 90.1-2007 7.53 W/m2 83.7 185.5 0.9%
ASHRAE 189.1-2009 6.78 W/m2 84.1 184.4 1.4%
Impact of Window Performance on Space Heat
60
80
100
120
An
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Heat C
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An
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Heat C
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An
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Heat C
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An
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on, kW
h/m
22 22
Electricity
0
20
40
60
Baseline U = 0.45SHGC = 0.4
U = 0.45SHGC = 0.3
U = 0.27SHGC = 0.4
U = 0.27SHGC = 0.3
U = 0.17SHGC = 0.3
U = 0.17SHGC = 0.2
Post U-Value with Pre SHGC
An
nu
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pace
Heat C
onsum
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on, kW
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An
nu
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pace
Heat C
onsum
pti
on, kW
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An
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pace
Heat C
onsum
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on, kW
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An
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pace
Heat C
onsum
pti
on, kW
h/m
Electricity
Gas
Air Flow
Space Heat Loss Distribution – Effect of Air Leakage
Mechanical
Natural Air
Leakage, 2.9,
3%
Natural Air
Leakage,
16.3, 16%
Conduction,
Air Tight Enclosure Air Leaky Enclosure – Open Windows
Conduction,
47.9, 53%
Mechanical
Ventilation,
39.7, 44%
Mechanical
Ventilation,
39.7, 38%
Conduction,
47.9, 46%
kWh/m2/yr, % Total Space Heat kWh/m2/yr, % Total Space Heat
Total Space Heat = 90.5 kWh/m2/yr
Total Space Heat = 103.9 kWh/m2/yr
Natural Air
Leakage, 2.5,
22%Conduction,
2.3, 20%
What if Good Enclosure & w/Heat Recovery Ventilation?
Air Tight Enclosure Air Leaky Enclosure – Open Windows
Mechanical
Ventilation
24%
Conduction
5%
Mechanical
Ventilation,
6.5, 58%
kWh/m2/yr, % Total Space Heat kWh/m2/yr, % Total Space Heat
Total Space Heat = 11.2 kWh/m2/yr
Natural Air
Leakage
71%
Total Space Heat = 30.3 kWh/m2/yr
Assumed flow rate of 50 cfm per suite
Impact of Different Make-up Air Flow Rates
125.0
100
120
140
160
An
nu
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pace
Heat C
onsum
pti
on, kW
h/m
An
nu
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pace
Heat C
onsum
pti
on, kW
h/m
An
nu
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pace
Heat C
onsum
pti
on, kW
h/m
An
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onsum
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on, kW
h/m
22 22
25.1 25.1 25.2 25.3 25.3 25.4 25.4 25.5 25.6 26.7 24.0
77.4 75.7 74.0 71.5 69.8 68.2 66.5 64.1 62.644.2
125.0
0
20
40
60
80
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
An
nu
al S
pace
Heat C
onsum
pti
on, kW
h/m
An
nu
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pace
Heat C
onsum
pti
on, kW
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An
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pace
Heat C
onsum
pti
on, kW
h/m
An
nu
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pace
Heat C
onsum
pti
on, kW
h/m
Gas
Understanding Energy Use in MURBs
Electric BaseboardHeaters in all
Gas fireplaces insome Suites
Air exhausted usingbathroom/kitchen fans
& windows
Air leakage of heatedventilation air through
elevator and stairwell shafts Ventilation air is heatedusing gas-fired make-up
air unit (MUA)
HeatedVentilation airfrom corridor
Domestic HotWater is heated
using Gas
- 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
Air flow throughopen windows
Elevator pumping
Parking GarageExhaust Fans
Parking Garage
Common Areas
PoolGas Boiler toheat pool &
hot-tubs
Suites
Heaters in allSuites
Some Gas & ElectricHeat at Common Areas
Typically Unheated
Rec. Areas
- Interior lighting- Elevators- Ventilation fans and motors- Parking garage exhaust fans- Water distribution pumps- Baseboard heaters- Recreation areas/pool pumps- Exterior lighting- Communication- Controls
- Baseboard heaters- Lighting- Appliances- Miscellaneous Electric Loads- Plug loads- Exhaust fans
Enclosure air-leakage
Air Flow within a Building
Building 20
Air Pressure Differential in Study Building (43)
22 storey highrise - Pressure Beneath Suite Doors
14
15
16
17
18
19
20
21
22
Theoretical
Average
Maximum
Linear (Theoretical)
Linear (Average) Measured air pressure across the corridor doors
-15 -10 -5 0 5 10 15
2
3
4
5
6
7
8
9
10
11
12
14
Flo
or
Pressure Differential (Pa)
Linear (Maximum) across the corridor doors of suites in a 22 storey building
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 suites4. Provide fresh air-directly to suites
5. Compartmentalization is needed
• Further research of air flow within buildings required
Investigation and analysis of condensation related problems at window-wall assemblies.
Monitored environmental conditions and mechanical system conditions:
Make-Up Air Investigation
Temperatures
Relative HumidityRelative Humidity
CO2
Operation of mechanical
equipment including
Heat pump
Cloths dryer
Exhaust Fans
Make-up air at suite door
Make-Up Air Investigation
Actual Airflow
2959Kitchen Fan - Level 3
1655Kitchen Fan - Level 2
1155Kitchen Fan - Level 1
1455Common Bathroom Fan
1153Guest Bathroom Fan
855Master Bathroom Fan
0 cfm24 cfmBaseline (no fans operational)
N301N601
Suite Number
27%183%% of ASHRAE Recommended with Continuous Master Bath Fan
0%79%% of ASHRAE Recommended @ Baseline
30 cfm30 cfmASHRAE Recommended (based on # of occupants, 15cfm/person)
10%67%% of ASHRAE Recommended with Continuous Master Bath Fan
0%29%% of ASHRAE Recommended @ Baseline
82 cfm82 cfmASHRAE Recommended (based on suite size = 0.3 ACH)
1455Dryer w/ Booster Fan
2959Kitchen Fan - Level 3
ASHRAE recommendations at 15 cfm per person for actual occupant loads
ASHRAE recommendations based on suite area (accounts for 5-6 occupants)
Air flow less affected by fan operation, hallway pressurization was not working
Control suite
Other Considerations
Fireplaces
Occupants
etc.
Other Considerations
77.4
80
100
120A
nn
ual S
pace
Heat C
onsum
pti
on, kW
h/m
An
nu
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pace
Heat C
onsum
pti
on, kW
h/m
An
nu
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pace
Heat C
onsum
pti
on, kW
h/m
An
nu
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pace
Heat C
onsum
pti
on, kW
h/m
22 22
Impact of Fireplaces – Why do we need them?
25.1 29.1
77.4
39.9
0
20
40
60
Baseline Pre With Fireplaces
Baseline Pre Without Fireplaces
An
nu
al S
pace
Heat C
onsum
pti
on, kW
h/m
An
nu
al S
pace
Heat C
onsum
pti
on, kW
h/m
An
nu
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pace
Heat C
onsum
pti
on, kW
h/m
An
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pace
Heat C
onsum
pti
on, kW
h/m
Gas
Electricity
Distribution of Energy Costs in MURBs
Total
Consumed By
Owner, 59.5,
29%Total
Consumed By
Strata, 146.9 ,
Electric
Baseboard
Heating, 24.8,
42%
Lights (Suite),
15.9, 27%
Plug and
Appliances
(Suite), 18.7,
31%
Owner PaidStrata, 146.9 ,
71%
Electric Baseboard
Heating, 0.3 , 0%
Fireplaces, 37.7 ,
26%
Ventilation Heating,
39.7 , 27%
DHW, 32.9 , 22%
Lights (Common),
3.7 , 3%
Equipment and
Ammenity
(Common), 28.3 ,
19%
Elevators, 4.2 , 3%
Owner Paid
Strata Paid
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
Disconnect Between Consumption and Billing
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
How Do We Do Better?
New Buildings to be Carbon Neutral by 2020
Where Do We Want To Go?
Biggest Opportunities in Existing Buildings
Reduce the loads
Getting to “Best Performance” Space Heating
Recover the heat
Impact of Cladding Attachment – R-15 of Insulation
Current Practice
R-7.4
Better
R-10.3
Even Better
R-11.6 to 14.4
Most Efficient
R-15.8
Retrofit and New Construction Enclosure Strategies
6
7
8
9
10
Ove
rall C
om
bin
ed
Wall a
nd
Win
dow
Encl
osu
re R
-valu
e
ASHRAE 90.1-2007 Compliance - Influence of Window Framing Type on Overall Enclosure R-value
Thermally Efficient Building Enclosures
Constructed with high performance
windows and well insulated walls
0
1
2
3
4
5
0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%
% Window Area
Ove
rall C
om
bin
ed
Wall a
nd
Win
dow
Encl
osu
re R
-valu
e
Study Buildings - Metro Vancouver
Average 50% glazing area
ASHRAE 90.1 - 2007 Compliant Buildings
Constructed with minimally compliant
wall and window R-values
Thermal Anatomy of a High Rise MURB
R-12 Insulation in wallsR-4 accounting for steel studs and slab edges
R-1.8 Windows aluminum window wall, low-e, air fillR-20 Roof Insulation65% Glazing
R-Value % of Enclosure % Heat loss
Walls 4 29 16.6
Strategy 1 Improve wall R-value to R10Strategy 2 Improve window R-value to R3.5Strategy 3 Reduce window area to 30%
Walls 4 29 16.6
Windows 1.8 65 82.7
Roof 20 6 0.7
Overall R-Value
2.3
Strategy 1 Improve wall R-value to R10
R-Value % of Enclosure % Heat loss
Walls 10 29 7.4
Windows 1.8 65 91.9
Roof 20 6 0.8
Overall R-Value
2.52.5
0.0
0.5
1.0
1.5
2.0
2.5
3.0
Base Strategy 1
Strategy 2 Improve Window R-value to R3.5
R-Value % of Enclosure % Heat loss
Walls 10 29 13.3
Windows 3.5 65 85.3
Roof 20 6 1.4
Overall R-Value
4.65.0
0.0
1.0
2.0
3.0
4.0
5.0
Base Strategy 1 Strategy 2
Strategy 3 Reduce Glazing to 30%
R-Value % of Enclosure % Heat lossWalls 10 64 41.9Windows 3.5 30 56.1Roof 20 6 2.0
Overall R-Value
6.57.0
0.0
1.0
2.0
3.0
4.0
5.0
6.0
7.0
Base Strategy 1 Strategy 2 Strategy 3
Reduced Glazing Area
Improved Ventilation Strategies
Corridor pressurized with small fans at each floor level
Combination Energy Efficiency Measures Simulated
ScenarioScenarioScenarioScenario Model InputsModel InputsModel InputsModel 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/ft2 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 = 0.35 t Air tightness “Tight – Low Average”, 0.05 cfm/ft2 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/ft2 t Make-up air temperature setpoint 60°F t 80% Heat Recovery
Simulated Space Heat Consumption Scenarios
102.4
95.6
67.4
80.0
100.0
120.0
An
nu
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pace
Heat C
onsum
pti
on, kW
h/m
An
nu
al S
pace
Heat C
onsum
pti
on, kW
h/m
An
nu
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pace
Heat C
onsum
pti
on, kW
h/m
An
nu
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pace
Heat C
onsum
pti
on, kW
h/m
22 22
Better windows, walls and air-tightness
Ventilation Heat-Recovery
45.0
38.2
9.7
0.0
20.0
40.0
60.0
Baseline Pre Baseline Post Good Best Good, WithoutFireplaces
Best, WithoutFireplaces
An
nu
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pace
Heat C
onsum
pti
on, kW
h/m
An
nu
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pace
Heat C
onsum
pti
on, kW
h/m
An
nu
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pace
Heat C
onsum
pti
on, kW
h/m
An
nu
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pace
Heat C
onsum
pti
on, kW
h/m
Total Building Energy Use
Can get ~100 kWh/m2/yr with ventilation and enclosure upgrades only
Further improvements from Domestic Hot Water, Lighting, Appliances, Controls etc.
200
250
An
nu
al Energ
y Co
nsu
mp
tio
n, kW
h/m
An
nu
al Energ
y Co
nsu
mp
tio
n, kW
h/m
An
nu
al Energ
y Co
nsu
mp
tio
n, kW
h/m
An
nu
al Energ
y Co
nsu
mp
tio
n, kW
h/m
22 22
110.3 109.897.5
76.960.8
39.4
96.0 89.7
73.8
72.181.3
74.2
0
50
100
150
Baseline Pre Baseline Post Good Best Good, WithoutFireplaces
Best, WithoutFireplaces
An
nu
al Energ
y Co
nsu
mp
tio
n, kW
h/m
An
nu
al Energ
y Co
nsu
mp
tio
n, kW
h/m
An
nu
al Energ
y Co
nsu
mp
tio
n, kW
h/m
An
nu
al Energ
y Co
nsu
mp
tio
n, kW
h/m
Gas
Electricity
R-Values
How Do We Get To Net Zero?
20
25
30
35
An
nua
l Suit
e E
lectr
ic S
pace
Heat C
onsu
mpti
on
, kW
h/m
An
nua
l Suit
e E
lectr
ic S
pace
Heat C
onsu
mpti
on
, kW
h/m
An
nua
l Suit
e E
lectr
ic S
pace
Heat C
onsu
mpti
on
, kW
h/m
An
nua
l Suit
e E
lectr
ic S
pace
Heat C
onsu
mpti
on
, kW
h/m
22 22
U = 0.45, 50% WWR
U = 0.45, 40% WWR
U = 0.45, 30% WWR
U = 0.45, 20% WWR
0
5
10
15
0 5 10 15 20 25 30 35 40 45 50
An
nua
l Suit
e E
lectr
ic S
pace
Heat C
onsu
mpti
on
, kW
h/m
An
nua
l Suit
e E
lectr
ic S
pace
Heat C
onsu
mpti
on
, kW
h/m
An
nua
l Suit
e E
lectr
ic S
pace
Heat C
onsu
mpti
on
, kW
h/m
An
nua
l Suit
e E
lectr
ic S
pace
Heat C
onsu
mpti
on
, kW
h/m
Wall Effective RWall Effective RWall Effective RWall Effective R----Value (hrValue (hrValue (hrValue (hr----ftftftft2222----F/Btu)F/Btu)F/Btu)F/Btu)
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
Near Net Zero – Effective Control of Air Flow
20
25
30
35
40
An
nu
al S
uite E
lect
ric
Sp
ace
Heat C
onsum
pti
on, kW
h/m
An
nu
al S
uite E
lect
ric
Sp
ace
Heat C
onsum
pti
on, kW
h/m
An
nu
al S
uite E
lect
ric
Sp
ace
Heat C
onsum
pti
on, kW
h/m
An
nu
al S
uite E
lect
ric
Sp
ace
Heat C
onsum
pti
on, kW
h/m
22 22
Enclosure 1: Windows U-0.17, 30% WWR,
Walls R-18.2
0
5
10
15
20
0 0.2 0.4 0.6 0.8 1
An
nu
al S
uite E
lect
ric
Sp
ace
Heat C
onsum
pti
on, kW
h/m
An
nu
al S
uite E
lect
ric
Sp
ace
Heat C
onsum
pti
on, kW
h/m
An
nu
al S
uite E
lect
ric
Sp
ace
Heat C
onsum
pti
on, kW
h/m
An
nu
al S
uite E
lect
ric
Sp
ace
Heat C
onsum
pti
on, kW
h/m
Air Leakage Rate, cfm/sfAir Leakage Rate, cfm/sfAir Leakage Rate, cfm/sfAir Leakage Rate, cfm/sf
Walls R-18.2
Enclosure 2: Windows U-0.45, 40% WWR,
Walls R-15.6
Typical Building
Simulated Air Leakage
Rate
Increased risk of moisture problems in more energy efficient buildings
Consider future maintenance and renewal costs
Final Thoughts - Energy Efficiency & Moisture Problems
Failure of “thermo-cladding”
Systemic LowSystemic LowSystemic LowSystemic Low----e e e e corrosion within corrosion within corrosion within corrosion within proprietary triple IGUs proprietary triple IGUs proprietary triple IGUs proprietary triple IGUs after 5 years after 5 years after 5 years after 5 years
Need for a New Approach
Courtesy of Bunting Coady Architects
Integrated Design Process
A New Approach for the Design of Buildings
A New Approach for the Design of Buildings
A New Approach for the Design of Buildings
A New Approach for the Design of Buildings
Discussion
Further Information / Background Information
CMHC Reports / Guides
Homeowner Protection Office Bulletins and Guides
Builder Insight No. 7
Building Enclosure Design Guide
Low-rise Requirements
BC Energy Efficiency Act - Windows
ProductProductProductProduct Maximum UMaximum UMaximum UMaximum U----ValueValueValueValueW/(m2·K) BTU/(hr·ft2·K)
Effective DateEffective DateEffective DateEffective Date
Vinyl and fibreglass windows and sliding doors
2.0 0.35 March 1, 2009
Tested with CSA A440.2-04 or NFRC 100-2004
Third party testing (SCC or NFRC accredited labs)
Permanent certification label, temporary U-value label
Exempts heritage buildings
Wood windows and sliding glass doors 2.0 0.35 January 1, 2011
Metal windows and sliding glass doors 2.57 0.452.0 0.35
June 1, 2009January 1, 2011
Skylights (for low-rise and high-rise) 3.1 0.54 March 1, 2009
High-rise Requirements
BC Energy Efficiency Act - Windows
ProductProductProductProduct Maximum UMaximum UMaximum UMaximum U----ValueValueValueValueW/(m2·K) BTU/(hr·ft2·K)
Effective DateEffective DateEffective DateEffective Date
Metal framed curtain wall, window wall and storefront products
2.57 0.45 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
and storefront products
Windows with framing materials other than metal, with or without metal reinforcing or cladding
2.0 0.35 January 1, 2011
Improved Ventilation Strategies
Corridor pressurized with small fans at each floor level
Questions?