Deep Green

Retrofits

Rob Dumont

Dumont and Associates

robdumont@hotmail.com

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