Why Deep Green?
1. We currently have a climate crisis. Climate scientists are calling for a reduction in carbon emissions of at least 2 times from current levels.
2. World population is expected to increase by a factor of 1.5 by 2050
3. Because there are so many people in poor countries, it is expected that average consumption per person in the world will increase by a factor of 3 before stabilizing.
Multiply these three factors together:
2 x 1.5 x 3 = 9
In other words, with that amount of growth in people and consumption, and the need to reduce carbon emissions, the only way to address the problem is reduce the carbon emissions of all buildings, transportation, industry and agriculture by a factor of 9.
What would sustainable
buildings look like?
Discovery 3 Home in Red
Deer, Alberta
One of Canada’s EQuilibrium Homes
Projected Net Zero Energy on an annual basis
Energy Conservation Features:
R87 Roof, R70 Walls, R60 Floor, R5 Windows, air tightness goal of 0.5 ac/h @ 50 pascals, Heat Recovery Ventilator
Energy Supply:
Passive solar, Active solar, 8.3 kilowatt PV system
Effect of Conservation and Renewable Energy Measures
259
138
0
42
5857
87
0
50
100
150
200
250
300
Base Case Hse 1. Reduce Space
Heat
2. Reduce Water
Heat
3. Reduce Lights
and Appliances
4. Space Cooling 5. Install Solar
Water Heat
6. Install
Photovoltaics
Conservation and Renewable Energy Measures
An
nu
al P
urch
ased
En
erg
y C
on
su
mp
tio
n (
kW
h/s
q.m
.)
Observations
1. Space Heating Load is the greatest single load
2. Water Heating Load is the second greatest load
3. LAME (Lights, Appliances and Misc) is the third greatest load
Reducing these three has the greatest impact on the house performance
Comparison of Inuvik and
Red Deer Climates
Inuvik Red Deer
Annual Heating
Degree Days
(C-days)
10,040 5550
Outdoor Design
Temp for heating
systems
-40.1 C -35.0 C
Annual Solar
Radiation on a
horizontal Surface
(GJ/m2)
3.3 4.9
Comparison of Inuvik and
Red Deer Climates
Inuvik Red Deer
Latitude Angle
(degrees)
68 52
Annual Solar
Radiation on a
South Facing
Surface tilted at
the latitude angle
(Gigajoules/m2)
4.7 6.5
Classic Analysis of Optimum
Amount of Insulation
Optimum amount of insulation is that
amount which minimizes the combined
cost of the installed insulation and the
cost of the fuel to heat the space
Consider only the cost of insulation and
cost of fuel
Cost of Batt Insulation
In southern Canada
Approximately
3 cents per square foot per R value
Thus R100 in a 1000 square foot attic
would cost about $3000
Cost of Rigid Insulation
Cost of Rigid Insulation
In southern Canada
Approximately
15 cents per square foot per R value
Thus R100 in a 1000 square foot attic
would cost about $15000
Optimum R value
= Square root( Cost of fuel x annual
heating degree days x present worth
factor x internal heat gain factor / cost of
insulation)
(This approach was used in the
development of the Model National
Energy Code for Houses for Canada)
Optimum R values for Inuvik
Heating Degree Days
Cost of Fuel
Can. $/litre
Cost of
Insulation
$/ft2 per R
value
Optimum R
value
English Units
H-ft2-F/BTU
0.50 0.03 44
1.00 0.03 63
0.50 0.06 31
1.00 0.06 44
Recommended Revised
Analysis of Optimum
Insulation Levels
Optimum amount of insulation is that amount
which minimizes the combined cost of the
installed insulation and the cost of the fuel
to heat the space
PLUS
the cost of the heating system.
PLUS the cost of the environmental damage
(Estimated at $200 per tonne of CO2)
What does a heating system
cost for a modest house
install?
Cheap: Electric baseboards ($1k -$2k)
Cheap: Point source heating ($2k-$5k)
Intermediate: Forced air with fossil fuel ($10k-15k)
High: Boiler system with fossil fuel ($15k -$30k)
Example of a Point Source
Oil Fired Space Heater
Toyotomi Space Heater
22,000 BTU/hr (6.4 kilowatts)
90% Efficient AFUE
$2600 Cdn including
Thru-wall vent kit
Comparison of Capital Costs
of Insulation plus Heating
Standard Code
House with Boiler
System
Insulation $5,000
Heating System
$20,000
$25,000
Superinsulated
House with Point
Source Heating
Insulation
$15,000
Heating System
$5,000
$20,000
Observation:
Consider the total cost of the thermal
comfort system including the heating
system, and not just the cost of the
insulation
Use an integrated design
Talk to Juergen Korn of Yukon Housing
Techniques for Super-
insulated Retrofits
Source Books:
The Super-insulated Retrofit Book by
Robert Argue (1982, Firefly Books,
available from www.amazon.com)
Keeping the Heat In by Natural
Resources Canada
Case Study
Double-Wall Double Roof
Retrofit
Location: Saskatoon
Annual Heating Degree Days: 5950 HDD
Celsius
1968 Bungalow
Pre-Retrofit
Post Retrofit
Pre-Retrofit
Comparison of Pre and Post
Pre-Retrofit Post-
Retrofit
Ratio
Post/Pre
Attic Insulation R20
RSI 3.5
R60
RSI 10.7
3.6
Wall Insulation
(Nominal)
R 7
RSI 1.2
R 47
RSI 8.3
4.3
Bsmt Floor
Insulation
R 0 No change ;
Later R20 was
added in
another expt.
Windows R2 R3 1.5
Air Tightness 2.95 ac/h @50
Pa
0.29 ac/h
@50 Pa
0.10
Energy Results
Peak Heat Loss reduced from 13.1 kW to
5.5 kW
Step 1. Cut off eaves and wrap roof
and walls with poly
(sometimes called the ―chainsaw
retrofit‖)
Step 2. Add second roof
Step 3. Add exterior wall
system
Step 4. Finish details
around windows & doors
Insulation of walls & bsmt
walls
R40 on Roof ; R40 on
Walls; R40 in Bsmt Walls
Post Retrofit—Asphalt
Shingles, Stucco Walls
February 2010 View of
House
Comparison of Pre and Post
Pre-Retrofit Post-
Retrofit
Ratio
Post/Pre
Attic Insulation R20
RSI 3.5
R63
RSI 12.5
3.6
Wall Insulation
(Nominal)
R 7
RSI 1.2
R 47
RSI 8.3
4.3
Bsmt Floor
Insulation
R 0 No change ;
Later R20 was
added
Windows R2 R3 1.5
Air Tightness 2.95 ac/h @50
Pa
0.29 ac/h
@50 Pa
0.10
The Super Insulated Retrofit
Book by Robert Argue &
Brian Marshall
Saskatchewan Examples
of Deep Green Retrofits
Before: 1950s Wood Frame
building with concrete block
foundation walls
Double wall, double roof
retrofit
1950s 4 Plex in Regina, Saskatchewan
Harold Orr was designer of the retrofit
Achieved an 82% reduction in air leakage
Achieved an 85% reduction in space heating
Former single forced air furnace with one thermostat for 4 suites was replaced by thermostatically controlled point source natural gas fireplaces (1 per suite)
Post-Retrofit
Use of point source heating
(fireplace) in each of the 4
suites.
New primary heating system
consisted of 4 fireplaces
Cost of new primary heating system:
4 fireplaces x $2500 = $10,000
Back bedrooms also each had one 500
watt electric baseboard heater (rarely
used, as the tenant pays for electricity,
while the landlord pays for natural gas)
Further information on the
entire sequence of the
retrofit
http://solaralberta.ca/power%20point
/Harold%20Orr.ppt
Roof retrofit
Roof Retrofit
First Double Wall Retrofit-
1978, Saskatoon House
Small House Retro – 1988
Double Wall Retrofit
Shed Roof on back of House was Double-Roofed
to address Condensation Problem
Custom Solar Builders, Saskatoon, did the work
Advantages of Double
Wall/Double Roof Retrofits
1. Conduction losses can be greatly reduced
2. Air leakage can be greatly reduced
3. Heating system can be greatly simplified in many cases because of the reduced heat loss. (e.g. Fireplace is sufficient to heat a modest space.)
4. Provides opportunity to address simultaneous need for upgraded roofing and siding.
5. Space on the interior is not lost.
6. House can be occupied while work is in progress
Summary
1. Because of global warming concerns, deep retrofits are needed for our existing housing stock.
2. Deep green double wall, double roof retrofits have a track record of proven performance dating back up to 30 years.
3. Optimum insulation levels depend on more than just the cost of fuel and the cost of insulation. Consider also the capital cost of the heating system
4.Let’s get on with it.
Acknowledgements:
Staff of the Institute for Research in
Construction of the National Research
Council of Canada
Harold Orr, who conceived the retrofit
strategy and guided its development
Private contractors, including Rod Gibson
of Custom Solar Builders, Saskatoon