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3 2 A S H R A E J o u r n a l a s h r a e . o r g J u n e 2 0 0 5

energy retrofitting consisting of a 40%eduction in delivered fuels and elec-

ricity supplied to these houses. A 40%

eduction in delivered energy sounded

like a laudable, if somewhat improbable,

oal. The research described here shows

ow five houses in the mid-Canadian

province of Saskatchewan approached

his 40% goal.

In Saskatchewan energy efficiency is

seen as a means of self-defense. Think

North Dakota, only colder. Midwinter

emperatures of 40C (40F) are com-

on. Houses in Saskatchewan are typi-

cally the tightest in Canada, as any winter

wind whistling through the envelope is

apt to kill nearby plants.

Reducing HouseEnergy Costs by 40%By Don Fugler, P.E., Member ASHRAE, Rob Dumont, Ph.D., Member ASHRAE,

and Tom MacDermott, Associate Member ASHRAE

The Kyoto Protocol1 requires participating nations to limit growth

of greenhouse gases, or reduce them, with the GHG production

of 2010 to be compared to a baseline of 1990.

The next several years will be a challenge for countries that are

not meeting goals. In Canada, the federal government has accepted

the national challenge posed by Kyoto and is looking for ways to

reduce GHG emissions. This article describes a Canadian research

pilot project on achieving major energy reductions in housing.

The pilot project had a somewhat more

ambitious goal than that set by govern-

ment policy makers dealing with Kyoto

requirements. In a report published in

1996 by Canada Mortgage and Hous-

ing Corporation,2 the consultant used a

slightly longer timeline (1988 to 2030).

He calculated what sort of residential

retrofit measures would need to occur so

that total residential greenhouse gases

would be lower in 2030 than they were

in 1990, despite a significant growth in

the number of houses and people.

In one scenario, all new houses would

need to be built better than the current

R-2000 energy efficiency guidelines.3

Moreover, a high percentage (80%) of

the existing stock would require extensive

005, American Society of Heating, Refrigerating and Air-Conditioning Engineers, Inc.

w.ashrae.org). Reprinted by permission from ASHRAE Journal, (Vol. 47, No. 6, June). This article may not be copied nor distributed in either paper or digital form without

RAEs permission.

About the AuthorsDon Fugler, P.E., is a senior researcher in the

Policy and Research Division of Canada Mortgage

and Housing Corp., Ottawa. Rob Dumont, Ph.D.,is section leader and Tom MacDermott is associ-

ate research engineer at the Building Performance

ection of the Saskatchewan Research Council in

askatoon, SK, Canada.

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J u n e 2 0 0 5 A S H R A E J o u r n a l 3 3

A productive low income weatherization program has existedfor the last two decades in American housing. Much of the

weatherization experience and knowledge comes from people

who have been energy retrofitting houses across the United

States, some in climates as severe as Canada. Heating season

savings of 15% to 30% in natural gas are achieved by the best

programs.4

The Canadian research was a little different in that both the

delivered natural gas and electrical energy were monitored, and

t was the annual use that counted. The houses

volunteered for the retrofit were not selected as

being high potential savers: all houses had attic

nsulation; all houses had some wall insulation;three of five houses had basement wall insulation;

all had at least storm windows; and three of five

already had setback thermostats. The houses represented typical

Canadian housing stock and its potential for retrofit.

The research agency of the consultant was large enough

to find five homeowners within its ranks to participate in the

study. Homeowners financed the retrofits themselves, based on

advice provided by the research team. They were given a small

honorarium in exchange for the disruption of their lives by the

team doing testing and monitoring. While the five houses may

more or less represent Canadian stock, it is likely that the fami-

lies selected from a research establishment are more willing to

participate in an energy retrofit than most other Canadians.The retrofit measures considered had to be commercially

available and have a simple payback of less than 15 years. The

nstalled measures could not compromise the health or safety

of the occupants, or degrade the indoor environment in the

pursuit of energy conservation. Preretrofit characterization

ncluded house airtightness testing by blower door, testing of

existing furnace and water heating efficiency, compilation of the

performance of various electrical appliances within the house,

and full documentation of house conditions to

permit modeling by the HOT2000 simulation

program.

All homeowners had to provide full utilityrecords and permit the collection of utility

data during the research period. The HOT2000

modeling for each house allowed for consideration of what

measures would be necessary to achieve the 40% target. In ret-

rospect, as homeowners managed the retrofit work themselves,

t would have been prudent to have set a goal somewhat higher

han 40%, so the target would be achieved even with partial

mplementation of measures.

Table 1 outlines some of the more common retrofits recom-

mended for the five houses. The D and G house nomenclature

s derived from the house selection process, and has been kept

only for congruence with the full report.6

The Canadian research was a little different in that both the delivered natural gas andelectrical energy were monitored, and it was the annual use that counted.

A 40% reduction in delivered

energy sounded like a laud-

able, if somewhat improb-

able, goal. The research de-

cribed here shows how five

ouses in the mid-Canadian

rovince of Saskatchewan

approached this 40% goal.

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easure

o es es es es

ondensing Induced Draft Furnace 60 kBtu/h 60 kBtu/h 60 kBtu/h 90 kBtu/h

Furnace 75 kBtu/h Input Input Input Input Input

22.0 kW, 80% 85% Efficient 17.5 kW 17.5 kW 17.5 kW 26.4 kW

ower ente o nsu ate esnsu ate esnsu ate es nsu ate esnsu ate

ater eater an an an an an

imney eave s s iminate iminate iminate iminate

asement aes es o o

es ninsuate

nsu ation ortions

es es es es

ttic nsu ation . . . .o

to at art

Windows Add Acrylic Pane In Living Room Add Acrylic Pane Add Acrylic Pane

ir ea ing es es es

New Major Appliances

e ri erator es o es oes ne se

ear

isconnect e rigeratorYes

es se

n asement ear

tove No No No No No

ot es as er es es es

ront oa ing

Dryer New

is was er ew

Existing Ones

Use 1472 kWh/Year and

reezers ear. ep ace

it nit

pprox. ear

ompact FluorescentYes Yes Yes Yes Yes

Lighting

ater onservat on easures

Toilet Dams Yes Yes Yes Yes Yes

ow ow ower ea s es es es es es

thernsta cient x aust ans es es es es es

Switch to IntermittentConsider Intermittent

urnace an peration,Furnace Fan Controller

onsi er ntermittent urnaceor ummer se

an ontro er

LandscapingRedirect SurfaceYes

Water Away From House

Table 1: Recommendations for common retrofits for the five houses.

The homeowners did follow through on most

recommendations. The predicted performance of

some retrofit measures far exceeded the energy

savings actually realized. Air sealing is a case inpoint. Two of the five houses (D1 and G3) were

very airtight, at less than two air changes per hour

at 50 Pa (0.2 in. w.g.) (ACPH ) during the blower

door test. No improvement to airtightness was rec-

ommended for these two houses. The other three

houses ranged from 6.26 to 7.71 ACPH 0. One cut

its air leakage rate in half through diligent retrofit

effort, but the other two houses only had marginal

improvements in airtightness. The lack of a robust

weatherization industry in Canada, unlike parts of

the United States, means that the expertise needed

for competent air sealing is uncommon.

Other shortcomings were due more to voli-

tion than expertise. At least one homeowner

pref er red the conve nien ce of computer s

constantly running to the energy savings ofturning them off during periods of non-use.

Some of the retrofits brought their own energy

penalties. Mechanically vented water heaters,

while helping to eliminate chimneys, had high

electrical power consumption. A replacement

furnace had a circulating fan that required twice

the power of the fan in the old furnace. These

inefficiencies had not been predicted in the

modeling exercises.

Figure 1 shows the comparison of natural gas

consumption of house G1 prior to and following

the retrofit work. The change in slope allowed

A do-it-yourself hot watertank insulation before the

retrofit.

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J u n e 2 0 0 5 A S H R A E J o u r n a l 3 5

calculation of gas reductions per degree day and permitted

normalization of the findings to a standard year.

The weather during the year following retrofit was milder

than most. Curiously, the incoming water temperature to the

house and water heater was 3C (5C) colder than normal. No

adjustment was made for the water temperature.

Table 2 shows the electrical and natural gas savings realized

n the project. The combined energy savings plus costs and pay-

back calculations are shown in Table 3 One house reached the

40% savings goal on total energy savings. The rest ranged from

24% to 31% improvement. The gas consumption savings werenormalized to account for variations

n weather during the monitoring

period that deviated from historical

averages. The data tabulated is from

the degree day correction. Data

modification by the control house

method showed even greater relative

energy savings.

In Table 3, costs do not include

labor contributed by the hom-

eowner, which was extensive in

some cases.

What Worked

The substitution of high-

efficiency furnaces in four of five houses for the original con-

ventional gas furnaces produced substantial and predictable

savings. Preretrofit instantaneous furnace efficiencies ranged

from 75% to 77.8%. The four high-efficiency furnaces had

measured efficiencies at the furnace of 90.9% to 92.6%. House

D1 had a mid-efficiency furnace installed, and its measured

efficiency was 78.8%.

Furnace electrical efficiency did not improve in a consistent

way. The motors providing the power venting for the high-effi-

ciency furnaces contributed 52 to 101 W when the burners were

on. The furnace circulating fans were sometimes higher and

sometimes lower in consumption than the fans in the replaced

furnaces. House G1 reduced the circulating fan high cycleconsumption from 703 to 323 W. House G3 saw a reduction of

420 to 230 W. However, in House G2 the consumption increased

from 290 to 380 W and in House G4 the furnace circulating

fan consumption jumped from 360 to 800 W with the furnace

replacement. House D1 and G3 ran their fans continuously for

ventilation purposes, despite the high energy costs that this

practice entails.

The water heaters originally located in the houses had

instantaneous efficiencies ranging from 74.1% to 82%. The

power-vented water heaters that replaced these units had slightly

higher efficiencies on average, 71.9% to 83.8%, but they also

contributed to an increase in electrical consumption with steadystate blower motor consumption of

65 to 95 W.

The sidewall vented water

heaters, combined with high-

efficiency furnaces, meant that the

existing chimneys could be sealed,

adding to the airtightness of the

house, likely reducing winter air

change rate, and reducing the risk of

combustion spillage. However, from

an energy consumption viewpoint,

the power vented water heatersmade marginal contributions to

savings, if any. A shortage exists

of inexpensive, energy-efficient

equipment for residential water heating. Instantaneously fired

units could be investigated for future retrofits.

The other reliable saving opportunity, besides furnaces, was

replacement of old electrical appliances with new, efficient units.

The original refrigerators consumed between 1100 to 1700 kWh

per year. The efficient units purchased were rated around 400 to

600 kWh/year. Similar savings were realized with freezer replace-

ments. House G3 replaced two old freezers with one new one,

dropping annual consumption from about 2300 kWh to just over

0 5 10 15 20 25 30 35 40

Heating Degree Days Per Day (C days/day)

30

20

15

10

5

NaturalGasConsumption(m

/day

reretro t

Post-Retrofit

Linear (Preretrofit)

Linear (Post-Retrofit)

otesPreretrofit data May 22, 1997 to June 9, 2001

Post-Retrofit data Feb. 17, 2002 to Dec. 31, 2002

Normalized Consumption = slope 6077 HDD + intercept 365 days

Pre = 0.6682 6077 + 0.2669 365 = 4158 m3

ost = . + . = . m3

avings = ost re =

Figure 1: Sample calculation for natural gas consumption.

Basement wall being insulated with the header in the midst of hav-ng foam board applied.

Table 2: Gas and electricity savings.

House Preretrofit Post-Retrofit Savings

as nnua u c eters

D1 4082 2842 30.4%

.

G2 4365 3100 29.0%

.

G4 6552 4855 25.4%

ectrc ty / ear

D1 9728 8847 9.1%

.

G2 8454 7155 15.4%

.

G4 7945 7440 6.4%

= .

y= 0.351x+ 0.4179

R2 = 0.9711

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400 kWh. The cheapest and ostensibly

easiest savings were simply to unplug the

beer fridge in the basement and save

the 1100 kWh that it used annually. Such

savings are more certain if the appliance

is actually thrown away or recycled, rather

than just unplugged. Substitution of com-

pact fluorescent lights (CFL) for com-

monly used incandescent bulbs shouldreduce energy consumption but the individual fixtures were not

monitored. Some premature CFL failures occurred with one

purchased brand.

Savings from house or water heater insulation, air sealing,

door replacement, low flow showerheads, and other improve-

ments could not be specifically attributed.

ouse otaTotal Simple

Cost, Payback,$Can Years

D1 26.5% 4,420 8.4

. , .

G2 26.9% 9,415 16.5

. , .G4 23.9% 7,225 11.5

Table 3: Retrofit costs and payback.

New HVAC and laundry equipment.

Lessons Learned

For houses without high-efficiency equip-

ment, saving 40% on energy bills or green-

house gas production can be achieved.

These research results suggest that the

recommended saving opportunities should

be in the 50% range for the 40% goal to be

realized for most homeowners.

The projected costs for such retrofits will be

$5,000 to $10,000 ($Can), and possibly more

f the homeowner contracts out all the labor.

The return on investment typically will be

better than found in mutual funds or bonds of

the last several years. The five homeowners in

the Saskatchewan project were satisfied with

the savings realized and the ancillary benefits

(e.g., more habitable basements).

Easy savings can be achieved through the

replacement of inefficient furnaces and majorappliances, particularly refrigeration equipment. Savings on water

heating equipment were more elusive. Computer modeling needs

to account for the electrical energy consumed by the motors on

gas appliances. This data may be hard to obtain from conventional

sources but is critical in the projection of electricity use.

This small project does not have enough data on the effects

of wall or attic re-insulation, or on envelope tightening to

quantify these effects. It is likely that retrofit work spurred by

the EnerGuide for Houses program7 will lead to contractors

having more experience and skills in these domains, which

will be more effective.

Homeowners may benefit from documentation that disag-gregates electrical loads, showing the impact of choices such

as maintaining a second refrigerator, continuous running of the

furnace circulating fan, or keeping electronic equipment such

as computers in constant operation. Electrical savings in this

pilot ranged from negligible to substantial. The gas savings

was more consistent.

References1. 1997. Full text of the Kyoto Protocol is available at www.emis-

sionstrategies.com/GHG/kpeng.htm.2. Cooper, K. 1996. Res ent a Retro t Potent a n Cana a. SAR

Eng neer ng report or Cana a Mortgage an Hous ng Corporat on.

. NRCan. 2004. Deta s on t e Natura Resources Cana a R-2000program can e oun at ttp: oee.nrcan.gc.ca res ent a personanew-homes/r-2000/About-r-2000.cfm?attr=12.

. Berry, L. and M. Schweitzer. 2003. Meta-evaluation of NationalWeatherization Assistance Program Based on State Studies, 19932002. Oak Ridge National Laboratory report (ORNL/CON-488) forthe U.S. Department of Energy.

5. NRCan. 2004. Down oa t e HOT2000 computer s mu at on pro-gram at www. u ngsgroup.nrcan.gc.ca so tware ot2000_e. tm .

6. Dumont, R.S., et a . 2003. Case Stu es o Ma or Home EnergyRetro ts. Sas atc ewan Researc Counc report or Cana a Mortgageand Housing Corporation.

7. NRCan. 2004. Details on the EnerGuide for Houses program canbe found at http://oee.nrcan.gc.ca/residential/energystar-energuide-

r2000.cfm?attr=4.

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