Publisher’s version / Version de l'éditeur: ASHRAE Journal, 21, 9, pp. 1-15, 1979-09
READ THESE TERMS AND CONDITIONS CAREFULLY BEFORE USING THIS WEBSITE. https://nrc-publications.canada.ca/eng/copyright
Vous avez des questions? Nous pouvons vous aider. Pour communiquer directement avec un auteur, consultez la première page de la revue dans laquelle son article a été publié afin de trouver ses coordonnées. Si vous n’arrivez pas à les repérer, communiquez avec nous à PublicationsArchive-ArchivesPublications@nrc-cnrc.gc.ca.
Questions? Contact the NRC Publications Archive team at
PublicationsArchive-ArchivesPublications@nrc-cnrc.gc.ca. If you wish to email the authors directly, please see the first page of the publication for their contact information.
NRC Publications Archive
Archives des publications du CNRC
This publication could be one of several versions: author’s original, accepted manuscript or the publisher’s version. / La version de cette publication peut être l’une des suivantes : la version prépublication de l’auteur, la version acceptée du manuscrit ou la version de l’éditeur.
Access and use of this website and the material on it are subject to the Terms and Conditions set forth at
A 'Modified' bin method for estimating annual heating energy
requirments of residential air source heat pumps
Cane, R. L. D.
https://publications-cnrc.canada.ca/fra/droits
L’accès à ce site Web et l’utilisation de son contenu sont assujettis aux conditions présentées dans le site
LISEZ CES CONDITIONS ATTENTIVEMENT AVANT D’UTILISER CE SITE WEB.
NRC Publications Record / Notice d'Archives des publications de CNRC: https://nrc-publications.canada.ca/eng/view/object/?id=87f9b860-eb0b-4e8a-8e4a-367c89f81f6c https://publications-cnrc.canada.ca/fra/voir/objet/?id=87f9b860-eb0b-4e8a-8e4a-367c89f81f6c
Ser
TH1
~ 2 1 d National Research Comeil national
no. 910
I$
Council Canada de recherches Canadacop 2 E3Llb~.
A
"MODIFIED" BIN METHOD FOR ESTIMATING
ANNUAL HEATING ENERGY REQUIREMENTS OF
RESIDENTIAL AIR SOURCE HEAT PUMPS
by RLD. Cane
Published in
ASHRAE Journal
VoL 21, No. 9, September 1979
p. 60.63
* DBR Paper No. 910
Division of Building Research
7
SOMMAIRE, --
L'auteur dgcrit une mEthode de compartimentation modifige pour la prgdiction des besoins gnerggtiques des pompes 5 chaleur rgsidentielles 5 source agrienne. A l'aide d'un exemple, il compare la mEthode proposge 2 celle recomrnandee par llASHRAE. L'auteur compare ensuite les rgsultats avec les besoins GnergGtiques rGels enregistrgs dans une habitation identique 5 celle consid6rse dans l'exemple. La msthode modifige donne des rgsultats beaucoup plus proches de la consommation observEe que la methode normalisge de 1'ASHRAE. - - - * P - - - L L
REQUIREMENTS OF RESIDENTIAL AIR SOURCE HEAT PUMPS
R.L.D. Cane*
ABSTRACT
This article outlines a "modified" bin method for predicting heating energy requirements of residential air-source heat pumps. An illustrative example compares the proposed method with that recommended by ASHRAE. The results are then compared with the actual monitored heating energy requirement of a house identical to the one considered in the example. The "modified" bin method prediction is much closer to the observed con- sumption than the result of the standard ASHRAE method.
The bin method outlined in the ASHRAE Handbook (Systems 1976
-
Chapter43) overestimates the amount of purchased heating energy needed in reasonably well insulated dwellings because it erroneously assumes that purchased heat is needed whenever the out side temperature is below 18.3OC
(6S°F). The "modified" bin method presented here treats internal and solar heat gains separately from heat loss and thereby determines the "break even" temperature below which the heating system needs to operate This will automatically lead to elimination of the bin hours that occur in the non-heating months of the year.
"Research Officer, Energy and Services Section, Division of Building Research, National Research Council of Canada, Ottawa, Canada KIA OR6
Estimating Heat Loss
A recent publication1 out lined a technique for estimating the "net" seasonal heat loss of the various components of a building's outer shell. The "net" heat loss values were determined by using a computer to evaluate the annual heating requirements of a "standard" and a "modified"
bungalow exposed to "testf1 year weather cycles for several locations across Canada. The consequence of increasing the area of windows and walls and varying the orientation of various components was examined in detail. The effect of exterior colour of walls and roofs was also evaluated.
Rather than applying a single degree day correction factor, CD, to the total heat loss rate, it was thought that each building component could be modified by a reduction factor derived from Ref. 1. To
quantify the reduction factors, it was necessary to estimate the heat loss in the absence of solar effects on external surfaces. For example, in the case of walls, solar absorptivity (a ) values of 0.45 and 0.90 were
S
used in Ref. 1 for light and dark surfaces respectively. The heat loss factor for the case as = 0 could be found by extrapolation. The result is illustrated in Fig. 1. The north-facing vertical surface was used as it was thought that the correction would be small and hence reduce the error
in the estimate. The heat loss factors obtained in this manner could then be compared with the values for cases of non-zero a
.
The ratio ofS
the heat loss factor for any other surface color to the value for a perfectly white opaque surface (aS = 0) is referred to as the seasonal heat loss reduction factor (SHLRF). This same procedure was applied to ceilings and windows. The SHLRF values are then multiplied by the design heat loss rate for the various components to obtain the adjusted heat loss rate as follows:
QL (i) = [Hwall0SHLRF + H
w ceiling SHLRF C
- 1
.
+
. . . l o (
At,)(Tindoor-Tmean (i)
1
The SHLRF applies to all above-grade portions of walls including doors W
and foundation. For below-grade portions of walls and the basement floor the SHLRF is assumed equal to 1. The seasonal heat loss reduction factors for walls, windows and ceilings are shown in Fig. 2.
One component of heat loss that remains to be included in Q (i) is L
the infiltration heat loss. In calculating design heat loss, infiltration
is typically assumed to be between 0.75 and 1.25 air changes per hour. 2
However, at other than design conditions it is highly unlikely that the air change rate is greater than 0.5 in reasonably tight construction. There is evidence to suggest that a more representative average value
(particularly new electrically heated homes) might be anywhere from 0.2 to 0.5 air changes per hour.3 The choice of a design infiltration rate and a seasonal rate must be made after careful examination of the
experimental data now available. 2
The final equation for the adjusted heat loss rate is:
QL
(i! = [ (Hwall *SHLRF + H *SHLRFw +...a
1 W 1 wal l2 2
...
+ Hfloor - 1 + H *SHLRF + H 1cei 1 ing c window
Estimating Heat Gains
In the previous section, the SHLRF for windows was set equal to 1
s e c t i o n , t h e s o l a r h e a t g a i n w i l l be c a l c u l a t e d s e p a r a t e l y .
The d i f f e r e n c e between t h e n e t h e a t l o s s and t h e h e a t l o s s f o r a p e r f e c t l y w h i t e opaque window ( i . e . , SHLRFwindow =1) r e p r e s e n t s t h e t o t a l u s e f u l s o l a r h e a t g a i n p e r u n i t a r e a o f window f o r t h e h e a t i n g s e a s o n . T h i s ' u s e f u l ' s o l a r h e a t g a i n (from F i g . 2) i s summed o v e r a l l f e n e s t r a - t i o n a r e a s a s f o l l o w s : - - " g a i n a l l wiidows ( g a i n A window
1
S S j j The f o l l o w i n g s h o u l d be n o t e d when c o n s i d e r i n g i n t e r n a l h e a t g a i n s from household e l e c t r i c i t y u s e and occupancy.(1) A l l e l e c t r i c a l e n e r g y consumed by a p p l i a n c e s and l i g h t s w i t h i n t h e h e a t e d s p a c e , d u r i n g t h e h e a t i n g s e a s o n , i s assumed t o c o n t r i b u t e an e q u i v a l e n t amount o f h e a t f o r s p a c e h e a t i n g . T h i s does n o t a p p l y t o a l l c a s e s , a s , f o r example, when w a t e r i s h e a t e d on t h e element o f a cooking r a n g e and s u b s e q u e n t l y poured down t h e d r a i n , b u t it s h o u l d be s u f f i c i e n t l y a c c u r a t e f o r e s t i m a t i o n p u r p o s e s .
( 2 ) For domestic h o t w a t e r h e a t e r s (assumed e l e c t r i c ) and a s s o c i a t e d plumbing, s t a n d b y l o s s e s r e p r e s e n t a p p r o x i m a t e l y 20% o f t h e t o t a l
e l e c t r i c a l e n e r g y consumption f o r h e a t i n g t h e w a t e r a c t u a l l y u s e d . 4 Half o f t h e remaining 80% i s assumed t o be l o s t down t h e d r a i n . Thus a p p r o x i m a t e l y 60% o f t h e e n e r g y u s e d f o r d o m e s t i c h o t w a t e r h e a t i n g i s u s e f u l h e a t g a i n t o t h e s p a c e d u r i n g t h e h e a t i n g s e a s o n .
( 3 ) The occupany p a t t e r n f o r t h e household must be assumed. For
example, based on an a v e r a g e occupancy o f 2 , f o r 12 h o u r s , a t 65 w a t t s p e r o c c u p a n t , t h e r e s u l t i n g h e a t g a i n i s a p p r o x i m a t e l y
The information regarding household electricity use for appliances, lights and domestic hot water heating is available from electric utility
5
surveys. One survey indicated the following average consumption data:
2 so 46 4
(a) Domestic hot water heating = 5000 kW*h/yr
-
2 7P(b) Appliances and lights = 7500 kW-h/yr (Muu;XhJi 1 9 7
A ~ W R M ) + L ' b I?-\ 3 klyL/t..
If it is assumed that electricity consumption is uniform over an
n
entire year, the heat gain would be 875 kW*h/month based on the data
from Ref. 5 . Combining this with the occupancy gain of 50 kW*h/month
yields an internal heat gain of 925 kW-h/month. - -- - - - -
Before the solar and internal gains can be incorporated into a bin analysis, the length of the heating season must be determined. As a first step, the months of June, July and August can be excluded. The remaining months can then be used to calculate the building break even temperature
as follows: L&P--- = k A
TBE = T
indoor
H =
gain [Hgain s + (Hgain I ) en] - ( 7 3 0 an)-'
The calculated value for the TBE can then be compared with the mean monthly temperatures for a locale. If the number of months with a mean
monthly temperature less than the T equals the assumed value for n, the
BE
value for H is correct. Otherwise, the value for n is changed and a
gain
new value for H is calculated.
gain
Hours of occurrence of outdoor temperature for the non-heating months should be excluded from the bins. The breakdown of hourly -
occurrence of outdoor temperature is generally available on a month-by-
6
month basis
.
"\Illustrative Example
The following example illustrates the application of the mcthod. The characteristics of a two-story single detached house with a heated
2
floor area of 164 m (including basement) are summarized in Table 1. For this analysis, the house is located in Ottawa, Canada (4673°C days).
, ,
Rather than using a single factor C each building component is D'
assigned a separate correction factor (SHLRF) derived from the "Net Annual Heat Loss Factor Method."' The values shown in Table 1, Col. 2, are
obtained from the various SHLRF plots by entering each plot at the degree days for Ottawa. The bracketed quantity in Col. 2 is the fraction of the total wall or door area in a particular orientation. The sum of the products of this value and its SHLRF yield an overall SHLRF to be
multiplied by the Design Heat Loss in Col. 1. Note that a SHLRF of 1 has been assigned for exposed floor, basement slab and below-grade walls, and that the below-grade heat loss is assumed constant and independent of indoor-outdoor temperature difference. A SHLRFI (infiltration) of 0.4 has been used, which is appropriate for tight construction. The
adjusted heat loss values (Col. 3) are summed over all components to yield an over-all adjusted heat loss characteristic which is analogous to the ASHRAE H /A CD.
t~
Solar heat gains through windows and the internal heat gains remain to be considered. For this example the useful solar heat gain during the heating season (Col. 4) is 2230 kW-h. Recall that the internal heat gain
(occupancy and electricity consumed within the heated space) was calculated to be 925 kW*h/month.
For the Ottawa area, the months of June, July and August are non- heating months. The total extraneous heat gain (assumed to be constant over the entire heating season) can be calculated using equation (5). H = (2230 kW*h + 925 kW*h/month x 9 months) x (730 hour/month x 9 months)-'
gain
-
7 , , 2 1 . 1
-
' b $ ~ d 7 .i'.71*1 =1.6 kW- 7 -
C,
ec;k.
+
U L f i L n L(W
+
9.
( L 5 . f&
+
d a c t ,Lwu-L r r lw w
- h p k*
b 5 ' ~ ) . . -.
The next step is fa,compare the new method with the procedure \
recommended by ASHRAE. ~ h ~ ~ b i n calculation using the adjusted heat loss characteristic from Col. 3 of\,~able 1 is shown in Table 2. For the ASHRAE method, the design heat'.loss characteristic from Table 1, Col. 1,
, --
is first multiplied by the factor C = 0.62, which is appropriate for D
a design outdoor temperature of -13'~.~ The ASHRAE bin calculation is summarized in Table 3. The characteristics of a commercially available air source heat pump of 2; ton (9 kW) capacity are used in the example.
Com~arison of the ASHRAE and "Modifiedtt Bin Method
Tables 2 and 3 reveal the basic differences in the two techniques. Column 1, in both tables, is the number of hours over which the calcula- tion is made. In Table 2, the months of June, July and August are not included, which results in 717 fewer hours than Table 3 in the temperature range 40-65'~. Most of these hours would occur overnight and, thus for this period would not require heating due to thermal storage effects in the building (i.e., warm, sunny days, cool nights). Column 10 of Table 3
indicates that 818 kW*h of heating energy would be supplied by the heat pump in the temperature range 60-65'~; in Table 2 the need for heating was offset by a combination of solar and internal heat gains.
The seasonal performance factor (SPF) is 15% higher when determined by the ASHRAE method than by the modified bin method. The ASHRAE method predicts a heating energy consumption and savings over resistance heating, 74% and 108% higher than that obtained by the modified method. This
would lead to a substantial over-estimation of the economic benefit of the heat pump.
The house in this example is one of four in an energy conservation project located near Ottawa jointly sponsored by the National Research Council of Canada and the Housing and Urban Development Association of Canada. The monitored results from an occupied dwelling indicate that
the heating energy supplied by an electric furnace to this dwelling is approximately 10,500 kW*h per year. This is in good agreement with the
predictions by the modified bin method (11,523 kW-h), but is much less
than the 20,070 kW-h indicated by the standard ASHRAE method.
Although not used in the example bin calculations, it is recommended
that part load correction factors be used. 8'9 In well insulated houses,
the heat pump balance point is considerably below the accepted 25'-35'F range, resulting in many hours of operation at a reduced load factor. This would result in a reduction in the SPF from that calculated here.
Conclusions
The proposed bin method using SHLRFs and a separate accounting for solar and internal gains provides an accurate estimate of heat loss and hence heat pump energy consumption in well insulated residential
construction.
The continued use of all hours of occurrence of outdoor temperature
below 18.3"C ( 6 5 O ~ ) without regard to time of year is not appropriate.
The outdoor temperature data are published in Canada in a format that allows separation of the hours on a month-by-month basis. If the
proposed method is used, the bins should include heating season hours of
occurrence from the thermostat set point down, since the solar and internal gains are treated separately (Table 2).
Acknowledeement
The author wishes to acknowledge the helpful discussions with his
colleague, G.P. Mitalas, whose work provided the basis for the SHLRF values.
This paper is a contribution from the Division of Building Research, National Research Council of Canada and is published with the approval of the Director of the Division.
Nomenclature A window j H gain I H g a i n S j H g a i n n
4,
( i ) SHLRFc SHLRFI SHLRF W 2 2-
n e t a r e a o f window j (m o r f t )-
design h e a t l o s s r a t e f o r c e i l i n g (kW) - design h e a t l o s s r a t e f o r basement f l o o r (kW)-
t o t a l monthly i n t e r n a l h e a t gain ( e l e c t r i c a l and occupancy)(kW0h/month)
2
- u s e f u l s o l a r h e a t gain f o r window j (kW-h/m )
-
average h e a t gain ( i n t e r n a l and s o l a r ) assumed c o n s t a n t (kW)-
design h e a t l o s s r a t e by i n f i l t r a t i o n (kW)-
design h e a t l o s s r a t e f o r wall (kW)-
design h e a t l o s s r a t e f o r window (kW)-
l e n g t h of h e a t i n g season (months)-
a d j u s t e d h e a t l o s s r a t e , b i n i (kW)-
seasonal h e a t l o s s r e d u c t i o n f a c t o r f o r c e i l i n g-
seasonal h e a t l o s s r e d u c t i o n f a c t o r f o r i n f i l t r a t i o n-
seasonal h e a t l o s s r e d u c t i o n f a c t o r f o r wall-
outdoor temperature a t which h e a t g a i n s j u s t o f f s e t h e a tl o s s (OC o r OF)
-
design indoor temperature (OC o r OF)-
mean outdoor temperature i n b i n i (OC o r OF)-
design indoor-outdoor temperature d i f f e r e n c e (deg C o r deg F)-
design indoor - mean outdoor temperature i n b i n i (deg C o r deg F)References
1. G.P. Mitalas. Net Annual Heat Loss Factor Method for Estimating Heat Requirements of Buildings. Nat. Res. Council of Canada, Div. Bldg. Res.
Bldg. Res. Note 117, 1976.
2. ASHRAE Handbook; 1977 Fundamentals
-
Chapter 21. American Society of Heating, Refrigerating and Air-conditioning Engineers.3. G.T. Tamura and A.G. Wilson. Air Leakage and Pressure Measurements of Two Occupied Houses.
~ S H ~ A E
Journal, Vol. 5, No. 12, 1963.4. Canadian Standards Associdtion. Performance Requirements for Electric Storage-Tank Water Heaters. CSA Standard C191-1973, June 1973.
5. V.S. Manian and A. Juchymenko. Energy Usage and Relative Utilization Efficiencies of Oil-, Gas-, and Electric-Heated Single-Family Homes. ASHRAE Trans. Vol. 81, Part 2, 1975.
6. Environment Canada. Atmospheric Environment Service. Hourly Data Summaries, July 1967.
7. ASHRAE Handbook; Systems 1976 - Chapter 43. American Society of Heating, Refrigerating and Air-conditioning Engineers.
8. C.E. Bullock and W.R. Reedy. Heat Pump Cyclic Performance and Its Influence on Seasonal Operation. Procs. 3rd Annual Heat Pump Technology Conference. April 10-11, 1978, Oklahoma State Univ., Stillwater, Oklahoma.
9. G.E. Kelly and J. Bean. Dynamic Performance of a Residential
Air-to-Air Heat Pump. Nat. Bur. Stds., Thermal Engineering Section, Center for Building Technology NBS Building Science Series 93, 1977.
TABLE 1
SUMMARY OF APPLICATION OF NEW METHOD
(1) (2) ( 3 ) (41 ( 5
1
Design Heat Seasonal U s e f u l Below-
Loss R a t e Heat Loss Adjusted S o l a r Grade
Area
I n s u l a t i o n , * (HL/AtD) * * Reduct i o n Heat Loss Heat Heat
Building Component m Nominal F a c t o r Rate ( a L / ~ t D ) Gain Loss
W/"C (SHLRF ) w/"C kW*h k W C e i l i n g 59.4 R5.6 11.6 0.68 7.9 Walls ( f a c i n g ) : N 30.0 R3.5 0.96(0.18) (windows S 43.0
"
39.0 o.81[ 0.67(0.26) 31.6 excluded) E 43.6 " ( T o t a l ) 0.84 (0.26) ( T o t a l ) W 48.8 I ' 0.84(0.29) Windows ( f a c i n g ) : N 5 . 9 T r i p l e Glazed S 5 . 8 " 33.2 1 . 0 33.2 E 0 . 9 I t ( T o t a l ) ( T o t a l ) W 0 . 0"
Doors (facing) : N 1 . 9 I n s u l . Door 5 . 8 0.96(0.61) 5 . 3
[windows P l u s Storm O.gl
[
excluded) E 1 . 2 " ( T o t a l ) 0 . 8 4 ( 0 . 3 9 ) Exposed Floor 3 . 7 R3.5 1.1 1.0 1.1 Basement x a l 1 8 . 9 R1.8 4.2 0.81 3.4 (above- grade ; windows excluded) A + & v * + * L ~ jy '
-
= I 7 9 51.k-
I n f i l t r a t i o n-
-
9 3 . 3 37.3 Lnur i % ~ L~,,.,, $ v ~ . 8 (0.75 a. c / h r )-
( 0 . 3 a . c / h r ) r T o t a l h e a t loss r a t e , W/*Crn
y * . 2 2 \ I I Basement slab*** 52.0 n i l 5 . 4 W/m 1 . 0 5.4 W/m 1 58 Basement w a l l f * * 2~79- \I, - I 0.95 (below-grade) 62.3 R1.8 10.75 I T 1 .O 10.75 I ' 2 2 3 0 r f l ? L '"L L'L = 2 4 7 9 . q * R v a l u e i s i n S I u n i t s ( m u l t i p l y by 5 . 6 7 f o r R v a l u e i n B r i t i s h U n i t s ) % -p
~ a p w . 4 b.3) s 3**
A t = 47.2 C d e g [72-(-131
-
E5 .F F 6.1 Z ' L***
D ' 3 2 3 0Belou g r a d e h e a t l o s s assumed c o n s t a n t and independent of o u t d o o r t e m p e r a t u r e
ht&% & X I 1 4 1
.c-J-
@ !A '3.L"$
TABLE 2,
f < (;.. . J - F1
MODIFIED BIN METHOD k,!
*Months o f J u n e , J u l y and August e x c l u d e d
Energy
A d j u s t e d Below Ave
.
Energy H e a t i n gOutdoor Heat Grade B u i l d i n g Ave
.
Power Consumed Consumed by EnergyTemp. Loss Supp 1 i e d
Number Heat Heat H e a t i n g Heat Pump I n p u t t o by
Range, R e s i s t a n c e by
O F
of ( 6 L / ~ t D x d ~ ~ Y LOSS, Gain, Required, C a p a c i t y , Heat Pump, Heat Pump, H e a t e r s , System,
Hours* k~ kW kW kW k W k W k W * h k W * h k W - h 65-69 215 0.20 60-64 293 0.53 55-59 398 0.87 50-54 475 1 . 2 0 45-49 491 1 . 5 3 40-44 554 1 . 8 7 35- 39 668 2.20 30- 34- _ 728 2 . 5 3 h i 0 . 0 1 2 . 6 4 . 2 0 0 0 0 . 0 1 1 . 7 4.0 0 0 0 0.22 1 0 . 8 3 . 8 3 1 0 8 7 0 . 5 5 9 . 9 3 . 7 98 0 261 0 . 8 8 9 . 1 3 . 4 161 0 432 1 . 2 2 8 . 2 3 . 3 272 0 676 1 . 5 5 7 . 3 3 . 1 440 0 1035 1.88 6 . 6 3.0 622 0 1369 , Z - 2 9 _ - 5SIj 2 . 7 , , 0,25 1 . 6 0 2.22 6 . 0 2.9 - 575 D -
-
1190 - 20-24 46 7 3.20 15- 19 383 3.53 10-14 348 3.87 5-9 2 75 4.20 0-4 210 4 . 5 3 -5 - -1 145 4.87 -10 - - 6 8 3 5.20 -15-
-11 4 1 5 . 5 3 -20 - -16 15 5 . 8 7 2.55 5 . 6 2.8 595 0 1191 2.88 5 . 2 2 . 7 573 0 1103 3.22 4 . 8 2 . 6 607 0 1120 3.55 4 . 3 2 . 6 590 0 976 3 . 8 8 3 . 9 2 . 5 522 0 815 4.22 3 . 3 2.4 348 133 6 12 4 . 5 5 2 . 7 2 . 3 19 1 153 378 4.88 2 . 3 2 . 1 8 6 106 200 5.22 2 . 0 1 . 9 2 8 48 78 6325 Y \ 5739 440 11523 2.87+
'9s
-
1.10 2 2 ;r2 2 2 , 5 3 ( 0 = 1\90 k v L Heating Energy S u p p l i e d by System
J
L o k u
i>
2,l--f- SPF = = 1 . 95
5
\iqo
-
\,,
1.9 kd =r 5 7 5 k'+JL Energy Consumed+ Energy Consumedb by Heat Pump by R e s i s t a n c e H e a t e r s
k *
N O ;
,&d U'L- 4-
I 1 A&*--+
TABLE 3 I ASHRAE B I N METHODC
13(21
.
(31 (41 ( 53
163
(73 (8) ( 9 ) (10) ', Energy HeatingOutdoor Heat Consumed Energy
B u i l d i n g Ave. Power Consumed by S u p p l i e d
R e s i s t a n c e by 55-59 692 0 . 3 9 $4 50-54 633 0
.
84 r.lL 540 45-49 1.
16 1 , ~ 1139 ':c\ x 565 40-44 1 .49 ',a\ 35-39 670 1 . 8 1 2.14 1849 2.70 728 30- 34 2.14 2,*& 2249 ? ~ t z 25-29 5 36 2 .46 2.1s 1828 . ' " 20-24 467 2.
78 3.11 1742 \ t a b 15-19 383 3 . 11 3.43 1555 lL77 10-14 348 3 . 4 3 3.15 1524 ' " 3 1 1292 ~ 3 % ;?'J.,Q
- --- .- ~ ~- - .- 4.":.Qe.- fq%o . / ----
. .,. . . ~ - -n
- 5 - -1 145 4.34 " ' 4 767 YLL -10-
-6 83 4 - 7 3 .a's 471 i:"F -15 - -11 4 1 5.05 ',7 15 -20 - -16 5 . 3 7 5 - 3 0 7042 7855 1099 " ' 20020 2 x 4 9 + , o ~ & ! 3 ' ? 5 = 5.63 H e a t i n g Energy S u p p l i e d by System 5.03n2to = b5L kwt* SPF = = 2 . 2 2 + 4 h,?. 3.9 r&?'o-
gJq kuh%'-
1 0 5 b - S I 9 = 2 3 1 k v k-
Energy Consumed + Energy Consumed3.9lco~
=
2 . 5 by Heat Pump by R e s i s t a n c e H e a t e r s~ . 5 ~ 2 1 , 3 = 525
kwh
1322kEnergy Saving o v e r R e s i s t a n c e H e a t i n g = 11116 kW-h
*
A l l 12 months i n c l u d e dThis publication is one of a s e r i e s of r e p o r t s produced by the Division of Building R e s e a r c h , National R e s e a r c h Council of Canada. No a b r i d g e m e n t of thie r e p o r t m a y be published with- out the w r i t t e n authority of the Division. E x t r a c t s m a y b e lished f o r p u r p o s e s of review only.
pub - Copies of thie and o t h e r publications of the Division m a y b e ob- tained by mailing the a p p r o p r i a t e r e m i t t a n c e (a Bank. E x p r e e s , o r P o s t O f f i c e Money O r d e r , o r a c h e q u e , m a d e payable to the R e c e i v e r G e n e r a l of Canada, c r e d i t NRC) to the Publications Section, Division of Building R e s e a r c h , National R e s e a r c h Council of Canada, Ottawa. K1A OR6. S t a m p s a r e not a c c e p t - able.
A l i s t of the publications of DBRJNRC i e available, on r e q u e s t , f r o m the P u b l i c a t i o n s Section of the Division.
