Calculated and measured energy consumption for "low energy" houses

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

Calculated and measured energy consumption for "low energy" houses

Figley, D. A.; Snodgrass, L. J.

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=40f4204f-8789-47a6-93ec-a57c1e9870f2 https://publications-cnrc.canada.ca/fra/voir/objet/?id=40f4204f-8789-47a6-93ec-a57c1e9870f2

no.

1446

National Research Con8eiI national

C . 2

I+

Council Canada da recherches Canada

BLDG

Institute for lnstitut de

- - _{Research in recherche en}

Construction construction

.

.

Calculated and Measured Energy

_{Consumption for "Low Energy" Houses}

by D.A. Figley and L.J. Snodgrass

Appeared in

Proceedings from the ACEEE 1986 Summer Study on Energy Efficiency in Buildings

Berkeley, CA. August 17 -23, 1986 VO~. 2, p.2.105-2.121

(IRC Paper No. 1446)

Reprinted with permission

Price $3.00 NRCC 27470 N R C

-

CISTI I R C

L I B R A R Y

APR

3

1987

C N R C - ICIST

I C

.-

SHORT ABSTRACT _, A T h i s p a p e r p r e s e n t s r e s u l t s o f a two-year e n e r g y a n a l y s i s o f 28 low-energy h o u s e s . The s p a c e h e a t i n g , d o m e s t i c h o t w a t e r h e a t i n g , and i n t e r i o r e l e c t r i c a l c o n s u m p t i o n s w e r e measured i n d i v i d u a l l y on a monthly b a s i s . V e n t i l a t i o n r a t e s were m o n i t o r e d and o c c u p a n t - r e l a t e d i n p u t s were documented u s i n g a q u e s t i o n n a i r e . T h e s e d a t a a r e compared w i t h v a l u e s c a l c u l a t e d u s i n g HOTCAN 2 . 0 , a m i c r o c o m p u t e r - b a s e d r e s i d e n t i a l e n e r g y - a n a l y s i s program.

COURT &SU&

C e document exp--- les r I s u l t a t s d ' u n e 6 t u d e d e d e u x arls p o r t a n t s u r 28 ----lament I n e r g ' e t i q u e . On a m e s u r g s u r u n f National Rese ~ a i s o n , l a Ser L I ~et d'eau arch Council

T K ~

consommation d e Of Canad, InstitMe f,, c h a u d e a a n i t a i _in 6lectrIque i n t g r i e u r e . On Pape, N21d ventilation e t c a l c u l 6 no*

1 4 4 6

d f u n q u e s t i o n n a i .

*

aux valeurs o b t e n u e s a i n f o r m a t i q u e d ' a n a l y s e d + -

-

1 -i - - -

-

. 1

D.A.

Figley

and

L.J.

Snodgrass

National Research Counci 1

of

Canada

ABSTRACT

An

increased awareness of residential space-heati

ng

energy costs has

stimulated the development of a new type

of

housing technology often referred

t o

as "low energyN construction. These houses incorporate

a

number

of

special

features including ai r - t i

g h t

vapor barriers, high 1 eve1 s

of

insulation,

and

mechanical venti 1 a t i

on

systems.

A

microcomputer-based resi denti a1 energy-analysi s program named

HOTCAN

2.0 has been developed in Canada

and

has become widely used for energy

budget calculations.

HOTCAN

2.0 incorporates a number of a1 gori thms for

calculating monthly heat flows through various buil ding components

and

a1

lows

the building designer

t o

evaluate the effect

of

changes. in the basic building

elements prior

t o

construction.

This paper outlines the results

of

a

two-year energy analysis

(HOTCAN

2.0

simulations) and field measurement study of 28 low-energy houses.

The space

heating, domestic hot-water heating,

and

interior electrical consumptions were

i ndi vi dual ly measured

on a

monthly basi s.

Venti 1 ation rates were moni tored

and

occupant-related inputs were documented using

a

questionnaire. These

d a t a

are compared with

HOTCAN

2.0 calculated values.

Various methods of analysing

the data are discussed.

Good agreement between the average measured

and

calculated overall heat

transfer coefficients was observed.

However, the calculated below-grade heat

losses were consistently low.

Since the below-grade heat losses were

a

substantial component

of

the t o t a l space heating

1 oad,

the calculated annual

space heating requi rements were a1 so significantly

1

ower t h a n the measured

values.

The results highlight the importance

of

being able

t o

input reliable

data into

an

energy analysis program.

The effect

of

an

error in estimating

the soi 1 thermal conductivity i s discussed.

CALCULATED AtJU MEASURED ENERGY CONSUbiPTION FOR "LOW ENERGY" HOUSES

0.A. F i g l e y and L.J. Snodgrass N a t i o n a l Research C o u n c i l o f Canada

u u r i n g t h e p a s t f i v e y e a r s , thousands o f " l o w energy" houses have been c o n s t r u c t e d i n Canada. F e a t u r e s o f t h e s e houses i n c l u d e h i g h l e v e l s o f i n s u - l a t i o n i n t h e c e i l i n g s (LRSI 7 ) and w a l l s O R S I 3.51, p r i m a r i l y t r i p l e g l a z e d windows and t i g h t l y s e a l e d a i r - v a p o u r b a r r i e r s

(11.5

ach 050 Pa as measured by t h e f a n d e p r e s s u r i z a t i o n t e s t

1

I l l .

A1 though t h e techno1 ogy o f b u i 1 d i n g t h e s e t y p e s o f houses i s becoming a c c e p t e d b u i l d i n g p r a c t i c e L2,31 d e t a i l e d measure- ments o f t h e i r i n s i t u t h e r m a l performance i s 1 im i t e d .

A r e s i d e n t i a1 e n e r g y - a n a l y s i s corr~puter program c a l l ed HOTCAN 2.0 L 4 j has become w i d e l y used as a d e s i g n t o o l t o p r e d i c t t h e thermal performance o f low- energy houses. The program p r o v i d e s a summary o f t h e m o n t h l y h e a t i n g power r e q u i rements based on t h e average i n d o o r l o u t d o o r a i r- t e m p e r a t u r e d i f f e r e n c e s and a l s o e s t i m a t e s t h e t o t a l annual h e a t i n g l o a d . V e r s i o n s o f t h i s prosram a r e used by v a r i o u s agencies, owners and c o n t r a c t o r s t o e s t a b l i sh d e s i g n c r i t e r i a f o r houses.

A s t u d y by bunont e t a1 L5J r e p o r t e d m o n t h l y energy consumption measure- ments on twenty-seven l o w energy houses u s i n g r e a d i n g s f r o m t h e u t i l i t y supp- l i e d energy meters. O f t h i s group, f o u r houses had a d d i t i o n a l sub-metering t o s e p a r a t e l y measure t h e energy i n p u t t o t h e space h e a t i n g and domestic h o t w a t e r systefi~s. F o r t h e o t h e r houses, t h e average summer t o t a l energy r e a d i n g s were used as an energy b a s e l i n e and t h e s e v a l u e s were s u b t r a c t e d f r o m w i n t e r mea- surements t o o b t a i n t h e c a l c u l a t e d space h e a t i n g energy consumption. HGTCAN

i . O _{was used t o c a l c u l a t e t h e space h e a t i n g consumption and r e a s o n a b l y good}

agreement ( w i t h i n +242 and -172) between t h e measured acd c a l c u l a t e d v a l u e s was o b t a i n e d f o r a sample o f 14 o f t h e houses.

A n o t h e r s t u d y LbJ compared t h e measured energy consumption o f f o u r unoc- c u p i e d t e s t h u t s w i t h HOTCAN 2.U c a l c u l a t i o n s . Again, good agreement between t h e measured and c a l c u l a t e d v a l u e s was r e p o r t e d .

S i n c e d e t a i l e d f i e l d s t u d i e s o f energy u t i l i z a t i o n i n l o w energy houses i n

c o l d Canadian c l i m a t e s a r e l i m i t e a , t h i s s t u d y was u n d e r t a k e n i n Manitoba on ' I

e l e c t r i c a l l y h e a t e d houses t o expand t h e d a t a base o f i n f o r m a t i o n on l o w energy house performance ana e x p l o r e some a s p e c t s o f energy consumption i n l o w energy

r e s i d e n c e s . The s t u d y s i t e s a r e l o c a t e d i n t h e Canadian p r a i r i e r e g i o n w h i c h

. .

has a c o n t i n e n t a l c 1 i m a t e L Z J . A1 though r e l a t i v e l y sunny ( 2 3 2 1 sunshine

h o u r s l y e a r )

,

t h e h e a t i ng season i s s e v e r e ( 5 9 2 3 " ~ _{d a y l y e a r}

,

_{18'C base}

1.

The purpose o f t h i s r e p o r t i s t o p r e s e n t measured performance d a t a f o r a group o f i d l o w energy houses and compare t h e r e s u l t s w i t h HOTCAN 2 . O

c a l c u l a t i o n s . The comparisons i n c l ude t h e o v e r a l l heat-1 oss c o e f f i c i e n t s f o r t h e b u i 1 dings and t h e 1 ong-term h e a t i n g energy consumptions.

Since HOTCAN 2.0 i s designed t o accept monthly i n p u t data, t h e experiment- a l d a t a were c o l l e c t e d on an approximately monthly b a s i s between October, 1983 and March, 19bS. The "months" used i n HOTCAN 2.O were a d j u s t e d t o correspond t o t h e f i e l a m o n i t o r i n g p e r i o d s .

HOUSE DESCRIPTION

A l l o f t h e houses were new, wood framed, s i n g l e f a m i l y residences w i t h f u l l depth c a s t - i n - p l a c e c o n c r e t e basement w a l l s . The f l o o r s l a b s were 75 mm concrete, c a s t over 1SU rml of g r a v e l p l a c e d on u n d i s t u r b e d s o i l

.

A1 1 o f t h e basements were i n s u l a t e d from t h e i n s i d e u s i n g wood studs w i t h g l a s s f i b r e b a t t i n s u l a t i o n between t h e studs. A continuous 15U LI m p o l y e t h y l e n e vapor b a r r i e r was a p p l i e d o v e r t h e i n s i d e f a c e o f t h e studs and t h e w a l l s were sheeted w i t h

12 mm gypsum board.

houses 1

-

4 were l o c a t e d i n Pinawa, Manitoba ( a p p r o x i m a t e l y 1 0 l ~ km n o r t h - e a s t o f ~ i n n i p e g ) and were c o n s t r u c t e d by c o n t r a c t o r 1. Houses

5

-

12 were a l s o l o c a t e d i n Pinawa, Manitoba b u t were c o n s t r u c t e d by c o n t r a c t o r 2 . _The

remaining houses 13

-

2 8 , were l o c a t e d i n Winnipeg, Manitoba and were c o n s t r u c - t e d by c o n t r a c t o r A.

The c o n t r a c t o r 1 houses had above-grade w a l l s c o n s t r u c t e d u s i n g t h e

double-stud technique L3J. A i r - t o - a i r h e a t exchangers (ATAHE) were used t o

supply o u t s i a e a i r and c i r c u l a t e a i r w i t h i n t h e houses. The u n i t s haci i n t e r - l o c k e d supply and exhaust fans w i t h t h e ON/OFF o p e r a t i o n c o n t r o l l e d by a humid- i s t a t . The exhaust a i r was removed ( v i a ductwork) from t h e k i t c h e n and bath- room. The o u t s i d e a i r was s u p p l i e d i n t o t h e c e n t r e o f t h e basement and a l l o w e d t o m i g r a t e through t h e house. F l o o r r e g i s t e r s were c u t through t h e main f l o o r t o f a c i l i t a t e a i r movement between t h e main f l o o r and basement. E l e c t r i c base- board h e a t e r s ( c o n v e c t i v e ) were used f o r space h e a t i n g .

The c o n t r a c t o r 2 _{houses had c o n v e n t i o n a l s i n g l e - s t u d above grade w a l l s.}

A i l o t h e r c o n s t r u c t i o n m a t e r i a l s and techniques were s i m i l a r t o those used by c o n t r a c t o r 1. E l e c t r i c f o r c e d - a i r h e a t i n g systems (20-kW i n p u t ) w i t h d u c t s s u p p l y i n g a i r i n t o every room and two c e n t r a l i z e d main f l o o r r e t u r n a i r g r i l l e s were .used. Outdoor a i r was s u p p l i e d v i a a 125-mm diameter d u c t connected t o t h e r e t u r n a i r plenum. The single-speed f u r n a c e f a n ('400 L / s ) o p e r a t i o n was c o n t r o l 1 ed by h e a t i ng aemand.

T a b l e I. House d e t a i l s .

I n s u l a t i o n l e v e l s

T o t a l i n t . RSI (mz 'C/W) No. o f A i r Year f l o o r area Heated - -

-

Space occup. t i g h t n e s s House o f Const. i n c l . bsmt. v o l . Wall C e i l . Bsmt. h e a t i n g adul t s l ( a c h @ code c o n s t . s t y l e ( m 2 ) ( m 3 w a l l system* ATAHE' c h i l d r e n 5 0 P a )

1 1982 Bungalow 183.3 464.5 7.3 9.0 3.5 E B Y 010 0.18 C o n t r a c t o r 1

-

2 1982 Bungalow 183.3 464.5 7.3 9.0 3.5 EB Y 0 I 0 0.14 3 1982 Bungalow 183.3 464.5 7.3 9.0 3.5 E B Y 211 0.16 P i nawa 4 1982 Bungalow 183.3 464.5 7.3 9.0 3.5 E B Y 3 I 0 0.15 5 1982 6 1982 C o n t r a c t o r 2

-

7 1982 8 1982 P i nawa 9 1982 10 1982 11 1982 12 1982 Bungal ow 14 S t o r e y Bungal ow Bungal ow Bungal ow Bungal ow 14 S t o r e y Bungal ow 477.0 3.5 7.0 2.1 EFA 451.9 3.5 7.0 2 . 1 EF A 507.5 3.5 7.0 2.1 EFA 545.0 3.5 7.0 2.1 EFA 477.0 3.5 7.0 2.1 EFA 545.0 3.5 7.0 2.1 EFA 451.9 3.5 7.0 2.1 EFA 507.5 3.5 7.0 2.1 EFA 13 1981 14 1981 C o n t r a c t o r 1

-

15 1982 16 1981 Winnipeg 17 1982 18 1981 19 1982 2 0 1983 2 1 1982 22 1981 2 3 1981 24 1981 25 1981 26 1981 2 7 1981 2 8 1981 S p l i t L. Bungal ow Bungal ow Bungalow Oungal ow Bungalow Bungal ow S p l i t L. Bungal ow Bungal ow Bungal ow Bungal ow Bungal ow Bungal ow S p l i t L. Bungalow 7.3 9.0 3.5 EB 7.3 9.0 3.5 E B 7.6 10.4 4.2 EFA 7.3 9.0 3.5 EB 7.3 9.0 3.5 E B 7.3 9.0 3.5 E B 7.3 9.0 3.5 E B 7.3 9.0 3.5 EB 7.3 9.0 3.5 EB 7.3 9.0 3.5 E B 7.3 9.0 3.5 E B 7.3 9.0 3.5 EB 7.3 9.0 3.5 EB 7.3 9.0 3.5 E B 7.3 9.0 3.5 EB 7.3 9.0 3.5 EB --

*EB = E l e c t r i c baseboard; EFA = E l e c t r i c f o r c e d a i r 'ATAHE = A i r - t o - a i r h e a t exchanger

MEASUREMENTS

The a i r t i g h t n e s s o f t h e houses was measured u s i n g t h e f a n d e p r e s s u r i z a - t i o n method [l]. The v a l u e s f o r t h e a i r leakage a t 50 Pa o f d i f f e r e n t i a l p r e s - s u r e a r e g i v e n i n Table 1. The t e s t i n v o l v e d b l o c k i n g t h e v e n t i l a t i o n d u c t s p e n e t r a t i ng t h e house envel ope, d e p r e s s u r i z i ng t h e house u s i n g an e x h a u s t fan and measuring t h e a i r f 1 ow, Q ( L / s )

,

and c o r r e s p o n d i ng v a l ue o f t h e d i f f e r e n t i a1 p r e s s u r e a c r o s s t h e b u i l d i n g envelope, AP(Pa) f o g a range o f d i f f e r e n t p r e s - s u r e s . V a l u e s f o r t h e f l o w c o e f f i c i e n t , C ( L / s n (pa)", and f l o w exponent, n

( d i m e n s i o n l e s s ) , were t h e n c a l c u l a t e d u s i n g t h e e x p r e s s i o n :

where

A = a r e a o f t h e b u i l d i n g envelope (m2)

The t o t a l v e n t i l a t i o n r a t e ( V T ) f o r t h e houses was c a l c u l a t e d as:

\

where

Vpl = average mechanical v e n t i l a t i o n f l o w r a t e ( a c h )

VI = i n f i l t r a t i o n f l o w r a t e ( a c h )

E q u a t i o n ( 2 ) i s an a p p r o x i m a t i o n . However, s i n c e t h e houses were v e r y a i r - t i g h t , t h e mechanical system p r o v i d e d most o f t h e t o t a l v e n t i l a t i o n a i r .

F o r t h e houses w i t h ATAHE, e l a p s e d t i m e meters were i n t e r l o c k e d t o t h e ATAHE f a n s t o r e c o r d 014 t i m e . The s u p p l y and e x h a u s t f l o w volume r a t e s were c a l c u l a t e d f r o m h e a t e d probe anemometer t r a v e r s e measurements i n t h e d u c t s . VM was c a l c u l a t e d by d i v i d i n g t h e t o t a l volunie o f a i r t h r o u g h t h e ATAHE d u r i n g each n o n i t o r i n g p e r i o a ( t o t a l r u n n i n g t i n e mu1 t i p l i e d by t h e average d u c t a i r volume f l o w r a t e ) by t h e t o t a l t i m e o f each m o n i t o r i n g p e r i o d . The ATAHE h e a t r e c o v e r y e f f e c t i v e n e s s was assumed t o be 50% [8]. I n most cases, t h e s u p p l y and e x h a u s t a i r f l o w s t h r o u g h t h e ATAHt were n o t e q u a l , so t h e l a r g e r of t h e two v a l u e s was used. T h i s w o u l d n o r m a l l y r e s u l t i n a m e c h a n i c a l l y i n d u c e d p r e s s u r e d i f f e r e n c e w h i c h would u p s e t t h e i n f i l t r a t i o n , however, s i n c e t h e i n i t i a l c a l c u l a t e d v a l u e s o f VI were r e l a t i v e l y s m a l l , no a t t e m p t was made t o c o r r e c t them. The v a l u e o f VNfor t h e houses w i t h f r e s h a i r i n t a k e s was c a l c u - l a t e d by mu1 t i p l y i n g t h e f u r n a c e ON t i n e by t h e average measured f r e s h a i r f l o w r a t e t h r o u g h t h e i n t a k e d u c t w i t h t h e f u r n a c e f a n ON ( 2 3 5 L / s f o r a l l houses) ana d i v i d i n g by t h e t o t a l t i m e o f t h e m o n i t o r i n g p e r i o d . The f u r n a c e ON t i m e was a p p r o x i m a t e d as t h e t o t a l measured f u r n a c e e l e c t r i c a l energy consumption

( k h h ) d i v i d e d by t h e r a t e d h e a t o u t p u t (20 k W ) .

S h a w ' s [ 9 ] m e t h o d was used t o c a l c u l a t e t h e i n f i l t r a t i o n r a t e (VI) u s i n g t h e v a l u e s f r o m t h e f a n d e p r e s s u r i z a t i o n t e s t . No c o r r e c t i o n was made f o r addi t i o n a l i n f i 1 t r a t i on t h r o u g h t h e a i r i n t a k e a n d / o r e x h a u s t d u c t s when t h e mechanical systems were n o t o p e r a t i n g .

FIGLEY

When t h e o u t d o o r w i n d speed was < 3 . 5 m/s and t h e i n d o o r / o u t d o o r tempera- t u r e d i f f e r e n c e was > 2 0 K, VI was c a l c u l a t e d u s i n g t h e e x p r e s s i o n :

where

3

V = house volume (m )

AT = average i n d o o r / o u t d o o r t e m p e r a t u r e d i f f e r e n c e ( K )

When A T was < 2 0 K and t h e w i n d speed was > 3 . 5 m/s, VI was c a l c u l a t e d as:

where

v = w i n d speed (m/s)

The summer v a l u e s o f V T w i l l n o t r e p r e s e n t t h e t o t a l v e n t i l a t i o n r a t e s i n c e windows were f r e q u e n t l y opened.

I n each house, t h e t o t a l e l e c t r i c a l energy and w a t e r consumption were r e a d from t h e u t i

1

i t y i n s t a l 1 e d meters. A d d i t i o n a l meters were i n s t a l 1 ed t o measure t h e e l e c t r i c a l energy suppl i e d t o t h e space h e a t i n g (SH) and domestic h o t w a t e r (UHW) systems and t o neasur-e t h e DHW f l o w volume. An a s p i r a t i n g psychrometer was used t o measure t h e m i d - h e i g h t t e m p e r a t u r e and r e l a t i v e h u m i d i t y a t each f l o o r l e v e l i n t h e houses. A1 1 o f t h e m e t e r , a i r f l o w , t e m p e r a t u r e and humidi

-

t y measurements were t a k e n a t a p p r o x i m a t e l y one month i n t e r v a l s . The t o t a l e l e c t r i c a l energy consumption t h r o u g h each m e t e r was d i v i d e d by t h e e l a p s e d t i m e f o r each n ~ o n i t o r i ncj p e r i od t o c a l c u l a t e t h e average power consumpti on.

The o u t d o o r a i r t e m p e r a t u r e d a t a were t a k e n f r o m l o c a l a i r p o r t weather s t a t i o n r e c o r d s [7].

S o l a r r a d i a t i o n d a t a were t a k e n f r o m t h e s t a n d a r d l o n g t e r m d e s i g n v a l u e s c o n t a i n e d w i t h i n t h e HOTCAN 2.0 program. Comparison o f l o n g t e r m and a c t u a l m o n t h l y t o t a l g l o b a l r a d i a t i o n d a t a [ l o ] i n d i c a t e d an average d i f f e r e n c e

( a c t u a l

-

l o n g t e r m ) of -1.6% w i t h a s t a n d a r d d e v i a t i o n o f 7.4%.

An independent e n g i n e e r i n g c o n s u l t a n t was h i r e d t o p r o v i d e c o n s t r u c t i o n q u a l i t y c o n t r o l f o r t h e houses. The c o n s u l t a n t ensured t h a t t h e houses were c o n s t r u c t e d i n accordance w i t h t h e b l u e p r i n t s

.

FIEASURED PERFORMANCE

The a v e r a g e m e a s u r e d h e a t i n g power i n p u t t o a house f o r each n i o n i t o r i n g p e r i o d , QIqT(kW), can be determines by t h e e x p r e s s i o n :

where

QSH = average power

s u p p l i e d

by t h e space h e a t i n g system (kW) QNE = average n e t e l e c t r i c a l power i n p u t t o t h e house (kW)

QDHW = average space h e a t g a i n f r o m t h e domestic h o t w a t e r system (kW) QPEOPLE = average n e t s e n s i b l e h e a t g a i n f r o m t h e occupants (kW)

QSOLAR = average space h e a t g a i n f r o m s o l a r energy (kW)

The average n e t e l e c t r i c a l power i n p u t t o t h e house was c a l c u l a t e d as:

where

QE = average t o t a l e l e c t r i c a l power usage (kW) QOUT = average o u t d o o r e l e c t r i c a l power usage (kW)

Homeowners were asked t o e s t i m a t e t h e average number o f hours o f use o f o u t d o o r l i g h t s and a p p l i a n c e s ( i n c l u d i n g b l o c k h e a t e r s ) so t h a t t h i s power c o u l d be deducted f r o n ~ t h e average t o t a l e l e c t r i c a l power consumption.

I t was assumed t h a t 8% o f t h e UHW power i s g i v e n up as h e a t t o t h e space ana t h a t t h e system has a 100 w a t t standby l o s s . T h i s assumption i s c o n s i s t e n t w i t h t h e c a l c u l a t i o n proceaure i n HOTCAN

2.0.

One comprehensive s t u d y Ell] t h a t has e x p l o r e d t h e r e 1 a t i o n s h i p between c o l a w a t e r supply t e m p e r a t u r e ana usage i n a d d i t i o n t o DHW usage suggests t h a t f o r l i g h t DHW u s e r s ( q 200 L l d a y ) , a p a r t f r o m t h e standby l o s s , t h e n e t h e a t

i n p u t f r o m t h e domestic w a t e r ( h o t and c o l d ) may be negl i g i b l e . F o r o c c u p i e d houses, 1 i f e s t y l e d i f f e r e n c e s w i t h t i m e and f r o m house t o house can cause s i g - n i f i c a n t v a r i a t i o n s i n t h e DHW h e a t g a i n , w h i c h a r e d i f f i c u l t t o q u a n t i f y .

Occupancy t i m e f o r p e o p l e was determined f r o m q u e s t i o n n a i r e s a d m i n i s t e r e d t o t h e homeowners. They were asked t o e s t i m a t e who o c c u p i e d t h e house and f o r how l o n g . F o r each occupant, t h e h e a t g a i n was assumed t o be

0.065

kW f o r a d u l t s and 0.033 kW f o r c h i l d r e n .

The average space h e a t g a i n f r o m s o l a r energy was n o t measured. The va- l u e s c a l c u l a t e d by HOTCAN

2.0

were used. U t i l i z a t i o n f a c t o r s

[12]

a r e a p p l i e d t o QsaLAR t o aciount f o r t h e b u i l d i n g ' s a b i l i t y t o use t h e a v a i l a b l e s o l a r r a d i a t i o n .

The t e r m " f r e e h e a t " ( Q F ) i s o f t e n u s e d t o d e s c r i b e t h e h e a t i n g power i n p u t t o a b u i l d i n g f r o m sources o t h e r t h a n t h e h e a t i n g p l a n t and can be c a l c u - l a t e ~ as:

QF = QNE + QDHW + QPEOPLE + QSOLAR ( 7 )

CALCULATED PEKFORI*IAI~CE

F IGLEY

moni t o r i ng p e r i o d s . The s t a n d a r d d e s i gn d a t a c o n t a i ned w i t h i n t h e program were r e p l a c e d w i t h measured d a t a f o r t h e o u t d o o r a i r t e m p e r a t u r e and deep ground t e m p e r a t u r e t o a c c u r a t e l y r e p r e s e n t t h e p r e v a i l i n g c o n d i t i o n s .

The r e q u i r e d program i n p u t s i n c l ude b u i 1 d i ng envel ope component s i zes and i n s u l a t i o n v a l u e s , i n f i 1 t r a t i o n and mechanical v e n t i l a t i o n r a t e s , QNE and DHW energy consumption, and i ndoor a i r temperature.

The b a s i c energy b a l a n c e i n HOTCAN 2.0 equates t h e average t o t a l c a l c u l a - t e c h e a t i n g p o w e r i n p u t t o t h e b u i l d i n g , Q (kW) w i t h t h e r e q u i r e d a u x i l i a r y space h e a t ( Q A U X ) and t h e a v a i l a b l e " f r e e he$?" sources:

by i n p u t t i n g f i e 1 d measured v a l u e s o f t h e n e t e l e c t r i c a l power consumption and DHW energy consumption, r e l a t i v e e r r o r s i n t h e s e i n p u t s have been removed. F o r r e f e r e n c e , T a b l e I 1 g i v e s t h e v a l u e s o b t a i n e d i n t h i s s t u d y and t h e average v a l u e s suggested i n HOTCAN 2.0.

ANALYSIS

The energy b a l a n c e e q u a t i o n s f o r a house ( e q u a t i o n s

( 5 )

and ( 8 ) ) can be i l l u s t r a t e d as shown i n F i g u r e 1. T h i s f i g u r e can be developed by p l o t t i n g t h e t o t a l h e a t i n g power i n p u t ((IMT and QCT) V S . t h e c o r r e s p o n d i n g average i n d o o r / -

o u t d o o r a i r t e m p e r a t u r e d i f f e r e n c e f o r each m o n i t o r i n g l ~ e r i o d . The non-space h e a t i n g p o w e r i n p u t s ( O F ) o f f s e t t h e b u i l d i n g p o w e r l o s s u n t i l t h e b a l a n c e p o i n t t e n p e r a t u r e d i f f e r e n c e ( A T E ) i s r e a c h e d . Beyond t h i s p o i n t (AT>AT8) a d d i t i o n a l space h e a t i n g power must be i n p u t t o s a t i s f y t h e h e a t i n g l o a d . E e l ow t h i s p o i n t , ( A T < A T B ) , t h e excess i n t e r n a l g a i n s lnust be removed o r t h e house t e m p e r a t u r e w i l l r i s e .

F o r t h e a n a l y s i s , t h e same v a l u e s of QSOLAKy QPEOP _{Q HW} and QNE were used i n t h e measured and c a l c u l a t e d energy e q u a t i o n s . he'rePore, f r o a equa- t i o n s ( 5 ) and

( a ) ,

t h e v a l u e s o f X and Y i n F i g u r e l r e p r e s e n t QAUX and QSH'

I n HOTCAN 2.0, t h e h e a t l o s s o f a s t r u c t u r e i s composed o f t h e sum o f t h e h e a t 1 osses due t o above grade c o n d u c t i o n , i n f i 1 t r a t i on, v e n t i 1 a t i on and be1 ow g r a d e c o n d u c t i o n . When t h e o u t d o o r a i r t e m p e r a t u r e ( T o ) i s g r e a t e r t h a n o r equal t o t h e average i n d o o r a i r t e n p e r a t u r e (Ti ) , t h e o n l y h e a t l o s s i s assumed t o be due t o t h e below grade s u r f a c e s . hi t a l a s

[ I 3 1

has shown t h a t t h e below grade component o f t h e h e a t l o s s i s r e l a t e d t o t h e ground s u r f a c e t e m p e r a t u r e

b u t can have a t i m e l a 9 i n t h e o r d e r o f months. Because of t h i s , 1 in e a r ex-

_.

_.

p r e s s i o n s t h a t r e 1 a t e t h e b u i 1 d i n g h e a t i n g energy 1 oad w i t h t h e i n d o o r / o u t d o o r

a i r t e m p e r a t u r e d i f f e r e n c e ( A T ) w i l l c o n t a i n some element of e r r o r . As t h e

r a t i o o f t h e below grade h e a t l o s s t o t h e t o t a l h e a t l o s s becomes l a r g e r , t h e

.

I

v a l i d i t y o f t h e 1 i near e x p r e s s i o n s becomes more q u e s t i o n a b l e . Despi t e t h i s shortcoming, one p o p u l a r method o f d e s c r i b i ng t h e h e a t 1 oss c h a r a c t e r i s t i c s o f

h o u s e s i s t o d e f i n e an o v e r a l l c a l c u l a t e d heat l o s s c o e f f i c i e n t U C ( ~ / " C )

o r Ub,

(experimental l y determi ned) such t h a t :

Table

11.

Suggested values i n

HOTCAN 2.0

and measured values f o r i n t e r n a l gain

parameters.

Measured

z

s

Val ue

HOTCAN

2.0

(average)

( s t d . dev.)

Daily base e l e c t r i c a l

consumption

( k W h / d )

14

26.0 8.1

Daily hot-water energy

consumption

(kWh/d)

14

13.0

4.7

C T B

A T , INDOOR - G U T D O O R T E M P E R A T U R E D I F F E R E N C E . K

F

IGLEY

The v a l u e o f U combines t h e h e a t l o s s c o e f f i c i e n t s f o r t h e above grade conduc- I t i o n , i n f i l t r a t i o n and v e n t i l a t i o n w i t h a p o r t i o n o f t h e below grade h e a t l o s s I c o e f f i c i e n t . The c o n s t a n t B r e p r e s e n t s t h e h e a t l o s s t h a t w i l l o c c u r when t h e

i n d o o r / o u t a o u r a i r t e m p e r a t u r e d i f f e r e n c e i s L O K. T h i s i s t h e average below grade h e a t l o s s f o r t h e summer months.

- '

Usi ng a 1 e a s t squares r e g r e s s i o n t e c h n i que, 1 i n e a r e x p r e s s i o n s o f t h e f o r m s o f e q u a t i o n s ( 9 ) and ( 1 0 ) were f i t t e d t h r o u g h t h e v a l u e s of QCT and QMT

f o r AT>lO K and v a l u e s f o r UC and UN and

BC

and BPI were c a l c u l a t e d ( T a b l e 111

1.

.

-

values-of t h e i n d e x o f d e t e r m i n a t i o n ( r 2 ) f o r t h e l i n e a r r e g r e s s i o n s a r e a1 so

g i v e n i n T a b l e 111. The hT=lO K c u t - o f f p o i n t was a r b i t r a r i l y chosen based on o b s e r v a t i o n s o f t h e p l o t t e d d a t a . F o r most o c c u p i e d huuses, t h e power consump- t i o n r a t e became non-1 i n e a r f o r AT<10 K ( F i g u r e 2 ) . Since a l m o s t a l l of t h e h e a t i n g r e q u i r e m e n t e x i s t s when A T l l O K, t h i s t e c h n i q u e can be usea t o a c c u r - a t e l y model t h e houses under a c t u a l c o n d i t i o n s .

To make a e c i s i ons a b o u t b u i 1 d i n g components, h e a t i n g system c o n f i g u r a t i o n s and f u e l t y p e s , house a e s i gners r e q u i r e a c c u r a t e i n f o r m a t i o n about t h e 1 ong t e r m space h e a t i n g energy r e q u i rements. A s t a n d a r d HOTCAN 2.0 o u t p u t p r o v i d e s an e s t i m a t e o f t h e annual space h e a t i n g energy c o n s u ~ p t i o n . The v a l u e s o f t h e measured ana c a l c u l a t e d t o t a l space h e a t i n g energy consumpti on f o r t h e i n d i v i

-

dual houses w i t h i n t h e t h r e e house groups a r e shown i n F i g u r e s 3, 4 and 5. S i n c e t h e m o n i t o r i n g p e r i o d s and house s i z e s v a r i e d , t h e t o t a l space h e a t i n g energy c o n s u n ~ p t i o n f o r each house was d i v i d e d by t h e t o t a l f l o o r a r e a and t h e e l a p s e d h e a t i n g degree days (18°C base) f o r t h e moni t o r i ny p e r i o d .

There a r e a number o f p o s s i b l e uses f o r t h e r e s u l t s f r o m a HGTCAN 2.0 c a l c u l a t i o n . These i n c l ude:

1 ) comparison o f t h e r e l a t i v e e f f e c t o f changes i n t h e b u i l d i n g envelope ( i .e. i n s u l a t i o n l e v e l s , window geometry, e t c . ) on t h e thermal p e r - formance o f t h e s t r u c t u r e p r i o r t o c o m p l e t i n g t h e f i n a l design.

2 ) c a l c u l a t i o n o f t h e h e a t i n g power r e q u i r e m e n t as a f u n c t i o n o f t h e i ndocjr/outdoor t e m p e r a t u r e d i f f e r e n c e .

3 ) energy budget e s t i m a t i o n s o f h e a t i n g energy use. These a r e o f t e n used t o e s t i m a t e u t i 1 i t y energy denand r e q u i rements and t h e r e 1 a t i ve energy c o s t s a s s o c i a t e d w i t h v a r i o u s h e a t i n g system c o n f i g u r a t i o n s .

S i n c e t h e e x p e r i m e n t a l d a t a a r e "who1 e house" measurements, no s p e c i f i c c o n c l u s i o n s r e g a r d i n g use 1 car1 be made. F o r t h e houses i n t h i s s t u d y , a r e p -

r e s e n t i ti ve annual h e a t 1 oss d i s t r i b u t i o n as ca1 c u l a t e d by HOTCAN 2.0 i s shown

_

i n F i g u r e 6.

Tab1 e I I I. Fjeasured and c a l c u l a t e d v a l ues o f o v e r a l l h e a t 1 oss c o e f f i c i e n t s and c o n s t a n t s .

u~

U~

B~

B~ House code (w/'c) ( w / ' c )

( W )

( W )

r 2 M

'*c

C o n t r a c t o r 1 1 P i nawa 2 3 4 C o n t r a c t o r 2 5 P i nawa 6 7 8 9 10 11 12 C o n t r a c t o r

I

13 Winnipeg

FIGLEY

yure

AT, INDOOR -OUTDOOR TEMPERATURE D I F F E R E N C E . K

2. H e a t i n g power b a l a n c e f o r house 14.

0 10 2 0 3 0 10 5 0

TOTAL M E A S U R E D SPACE HEATING E N E R G Y C O N S U M P T I O N , ~ J / D D ~ ' '

F i g u r e 3. C a l c u l a t e d vs. measured space h e a t i n g energy consumption f o r unoccupied c o n t r a c t o r 1 and 2 houses.

TOTAL MEASURED SPACE HEATING ENERGY C O N S U M P T I O N , k ~ / D D r n ~

F i g u r e 4. C a l c u l a t e d vs. measured space h e a t i n g energy consumption f o r

o c c u p i e d c o n t r a c t o r 1 houses.

0

0 10 2 0 30 4 0 50

T O T A L MEASURED SPACE HEATING ENERGY C O N S U M P T I O N , k ~ / D ~ r n ~

F i g u r e 5. C a l c u l a t e d vs. measured space h e a t i n g energy consumption f o r

ABOVE WALLS FIGLEY INFILTRATION AND VENTILATION ( 2 0 % ) GRADE (15 %) ASEMENT FLOOR SLAB ( 2 5 % ) DOORS ( I O/o) ABOVE GRADE BASEMENT WALLS CE!LING (10 % ) BELOW GRADE

BASEMENT WALLS WINDOWS

(13 % ) (12 %)

F i g u r e 6. Annual h e a t l o s s d i s t r i b u t i o n f o r a t y p i c a l house.

W i t h r e s p e c t t o t h e second use, t h e i n d i v i d u a l house d a t a f r o m Table 111 were d i v i d e d i n t o 3 groups:

1) unoccupied c o n t r a c t o r 1 houses 2 ) o c c u p i e d c o n t r a c t o r 1 houses 3 ) o c c u p i e d c o n t r a c t o r 2 houses

and group average v a l u e s of

U,,,,,

UC, Eb, and BC were c a l c u l a t e d ( T a b l e I V ) .

T a b l e I V . Average v a l u e s o f o v e r a l l h e a t l o s s c o e f f i c i e n t s and c o n s t a n t s f o r t h e house group. M

c

M

c

House (W/"C) ( w / " c ) (W) (W) C o n t r a c t o r

1

& 2 77.1 77.1 1088 888 (unoccupied) C o n t r a c t o r 1 86.3 80.3 893 713 ( o c c u p i e d ) C o n t r a c t o r 2 114.6 111.7 996 729 ( occupied)

F o r t h e unoccupied c o n t r a c t o r 1 houses, t h e average o f t h e c a l c u l a t e d and measured v a l u e s o f U were 77.1 w/"C. T h i s suggests t h a t t h e a1 g o r i thms i n HOT(;AN 2.0 can e s t i r r ~ a t e th e h e a t l o s s a s s o c i a t e d w i t h t h e above grade b u i l d i n g conlponents dnd o u t d o o r a i r exchange and p r e d i c t t h e u t i l i z e d s o l a r r a d i a t i o n .

The average c a l c u l a t e d o v e r a l l h e a t 1 oss c o e f f i c i e n t s f o r b o t h groups o f

o c c u p i e d houses were s l i g h t l y l o w e r t h a n t h e measured v a l u e s (7% f o r c o n t r a c t o r

1 and 3% f o r c o n t r a c t o r 2 ) .

The a v e r a g e v a l u e o f B f o r t h e u n o c c u p i e d c o n t r a c t o r 1 houses was 18%

h i g h e r t h a n t h e c a l c u l a t e d va

y

ue, s u g g e s t i n g t h a t t h e c a l c u l a t e d basement h e a t

l o s s may be low. The BM v a l u e s were a1 so h i g h e r t h a n t h e c a l c u l a t e d v a l u e s f o r

t h e occupiea c o n t r a c t o r 1 houses (20%) and o c c u p i e d c o n t r a c t o r 2 houses (27%).

The c a l c u l a t e d v a l u e s were o b t a i n e d u s i n g t h e HOTCAN 2.0 suggested v a l u e s f o r

t h e u p p e r / l o w e r s o i l thermal c o n d u c t i v i t y o f k = 0.8

-

0.9 w/m°C. D e t a i l e d

s o i l i n v e s t i g a t i o n s were n o t conductea, however, general o b s e r v a t i o n s i n d i c a t e d

s o i 1 s [14] t h a t s h o u l d have c o n d u c t i v i t i e s i n t h e range o f k = 1.2

-

1.35

w/m°C. The HOTCAN 2.0 c a l c u l a t i o n s f o r house 1 were re-done u s i n g t h e h i g h e r

s o i 1 c o n d u c t i v i t i e s and t h e v a l u e o f B i n c r e a s e d f r o m 1.08 t o 1.25 kW, r e d u c i n g t h e d i f f e r e n c e between t h e measured and c a l c u l a t e d v a l u e s f r o m 27% t o 16%. Thus, much o f t h e i n i t i a l d i f f e r e n c e between t h e c a l c u l a t e d and measured v a l u e s

o f Q c o u l d have r e s u l t e d f r o m t h e l o w s o i l c o n d u c t i v i t i e s used i n t h e c a l c u l a -

ti on.

F i g u r e s 3, 4 and 5 show t h a t f o r a l l o f t h e house groups, t h e measured

space h e a t i n g energy consumption exceeded t h e p r e d i c t e a values. F o r t h e

unoccupiea c o n t r a c t o r

1

houses, t h e average r a t i o o f QSH/QAUX

( X )

was 1.11 w i t h

a s t a n d a r d d e v i a t i o n ( s ) o f 0.11. F o r t h e o c c u p i e d c o n t r a c t o r 1 houses,

X

=

1.37 a n d s = 0.42 and f o r t h e o c c u p i e d c o n t r a c t o r 2 houses,

X

= 1.29 and s =

0.39.

P o s s i b l e reasons f o r t h e HOTCAN 2.0 u n d e r - p r e d i c t i o n o f t h e t o t a l space h e d t i ng energy consumpti on a r e :

i

1 ) undocumented c l o s i n g o f window shades ( r e d u c i n g p o s s i b l e s o l a r g a i n )

2 )

undocumented opening o f windows and doors ( i n c r e a s e d h e a t l o s s f r o m

i n f i 1 t r a t i on )

3 ) i n a c c u r a t e e s t i m a t i o n and/or i n c o m p l e t e u t i 1 iz a t i o n o f i n t e r n a l g a i n s . F o r t h e unoccupied houses, a l o w c a l c u l a t e d basement h e a t l o s s c o u l d account

f o r t h e Q S H / Q A U X r a t i o o f 1.11. With t h e o c c u p i e d houses, t h e p r e v i o u s l y o u t

l i n e d occupancy and basement e f f e c t s c o u l d be r e s p o n s i b l e . CONCLUSIONS

.

'

The r e s u l t s f r o m t h i s s t u d y l e a d t o a number o f o b s e r v a t i o n s c o n c e r n i n g energy s t u d i e s on r e s i d e n t i a1 b u i 1 d i n g s :

-

*

1 ) HOTCAN 2.0 e ~ t i m d t e d t h e thermal performance o f t h e houses, t h e excep-

t i o n b e i n g t h e below grade h e a t l o s s . T h i s h i g h l i g h t s t h e i m p o r t a n c e

o f h a v i n g a c c u r a t e , d e t a i l e d d a t a on i n s i t u s o i l c o n d i t i o n s and a

FIGLEY

2 ) It i s d i f f i c u l t t o account f o r occupancy e f f e c t s i n houses. I n c r e a s e d n a t u r a l v e n t i l a t i o n and v a r i a t i o n s i n t h e u t i l i z a t i o n o f s o l a r and i n t e r n a l g a i n s i n t r o d u c e e r r o r s t h a t a r e beyond t h e b u i 1 d i n g d e s i g n e r s c o n t r o l

.

The t o t a l measured space h e a t i ng energy consumptions were s u b s t a n t i a l l y h i g h e r t h a n t h e t o t a l c a l c u l a t e d values. T h i s f a c t i s

s i g n i f i c a n t when economics and t h e i m p a c t o f " l o w energy" h o u s i n g t e c h -

..

no1 ogy on energy consumption a r e c o n s i dered.

3 ) S u b s t a n t i a1 v a r i a t i ons i n t h e measured vs. c a l c u l a t e d thermal p e r f o r -

mance o c c u r r e d f r o m house t o house. A1 though these v a r i a t i o n s occur -

red, t h e p h y s i c a l pher~omena c a u s i n g them c o u l d n o t be determined f r o m t h i s study.

REFERENCES

1. O r r , H.W., F i g l e y , D.A., "An Exhaust Fan Apparatus f o r Assessing t h e A i r Leakage C h a r a c t e r i s t i c s o f Houses", BRN No. 156, D i v i s i o n o f Bui 1 d i n g Research, N a t i o n a l Research C o u n c i l o f Canada, Gttawa, O n t a r i o , March, 1980.

2 . _{"Energy E f f i c i e n t Housing}

-

_{A P r a i r i e Approach", Saskatchewan Energy and}

b l i nes, Energy C o n s e r v a t i o n , Regina, Saskatchewan, 1982.

3. O r r , H.W., "Design and C o n s t r u c t i o n o f Low Energy Houses i n Saskatchewan", BPN. No. 30, D i v i s i o n o f B u i l d i n g Research, N a t i o n a l Research C o u n c i l o f Canada, Ottawa, O n t a r i o , A p r i l , 1982.

4. Dumont, R.S., Lux, M.E., Orr, H.W., "HOTCAN: A Computer Program f o r E s t i - m a t i ng t h e Space H e a t i ng Requi rement o f h e s i dences"

,

DBR Computer Program No. 49, D i v i s i o n o f B u i l d i n g Research, N a t i o n a l Research C o u n c i l o f Canada, Ottawa, O n t a r i o , September, 1982.

5. Dumont, R.S., Orr, t i . .

,

Hedl i n , C. P., "Low-Energy Houses: Measured

Energy-Consumption F i g u r e s " , ASHRAE T r a n s a c t i o n s 1983, V.89, Pt.1, American S o c i e t y of H e a t i ng, Ref r i g e r a t i ng and A i r-Condi t i o n i ng Engineers

,

I n c . At1 a n t a , G A Y 1983.

6. Lumont, R.S., O r r , H.W., Lux, Fl.E., "Compari sun o f Energy Consumption C a l - c u l a t i ons U s i n g HOTCAN w i t h Measured Val ues f r o m Unoccupied T e s t Huts", Proceedings o f t h e 9 t h Annual Conference o f t h e S o l a r Energy S o c i e t y of Canada, Windsor, O n t a r i o , 1983.

7. "Monthly Meteor01 o g i c a l Sumnary"

,

Atmospheric Envi r o n n e n t S e r v i c e , Envi

-

ronment Canada, Uownsview, O n t a r i o , 1983-1985.

8. Heat Recovery V e n t i 1 a t o r T e s t i ny

-

P r e l i r n i n a r y R e s u l t s , T e c h n i c a l Report

.

.

Summary, Energy, M i nes and Resources Canada, 1984.

9. Shaw, C . Y . , "A C o r r e l a t i o n Between A i r I n f i l t r a t i o n and A i r T i g h t n e s s f o r houses i n a Uevel oped Resi d e n t i a1 Area", ASHRAE T r a n s a c t i o n s 1981, V.87, Pt.2., American S o ~ i e t y o f H e a t i n g , R e f r i g e r a t i n g and A i r-Condi t i o n i ng

Engineers, lnc., A t l a n t a , GA, 1981.

10. "Flonthly R a d i a t i o n Summary", Atmospheric Envi ronmer~t Service, Environment Canada, Downsview, O n t a r i o , 1983-1985.

11. Barakat, S.A., "Net Energy C o n t r i b u t i o n o f Domestic Water Use t o House h e a t i n g Requirements", BRk No. 209, O i v i s i o n o f Dui 1 d i n g Research, N a t i o n a l Research Council o f Canada, Ottawa, O n t a r i o , tiarch, 1984.

12. b a r a k a t , S.A., Sander, D.FI, "A Simple Method f o r Determining t h e H e a t i n g Requi r e ~ n e n t s o f U i r e c t - G a i n Passi ve Sol a r Houses", BRN No. 195, D i v i s i o n of B u i l d i n g Research, N a t i o n a l Research Council o f Canada, Ottawa, O n t a r i o , September, 19b2.

13. k i t a l a s , G.P., "Basement h e a t Loss S t u d i e s a t UBR/NRCM, DBR Paper No. 1045, NKCC 20416, D i v i s i on o f Bui 1 d i ng Research, N a t i o n a l Research Counci 1 of Canada, Ottawa, O n t a r i o , September, 1982.

14. F i g l e y , U.A., Snodgrass, L.J., "Measured Soi 1 Thermal C o n d u c t i v i t i e s and b i o d i f i e d Design Curves f o r P r e d i c t i n g F r o s t P e n e t r a t i o n Adjacent t o I n s u l a - t e d Foundations", d r a f t r e p o r t , I n s t i t u t e f o r Research i n C o n s t r u c t i o n , N a t i o n a l Research Council o f Canada, Ottawa, O n t a r i o , March, 1986.

T h i s p a p e r i s b e i n g d i s t r i b u t e d i n r e p r i n t f o r m by t h e I n s t i t u t e f o r R e s e a r c h i n C o n s t r u c t i o n . A l i s t of b u i l d i n g p r a c t i c e a n d r e s e a r c h p u b l i c a t i o n s a v a i l a b l e f r o m t h e I n s t i t u t e may b e o b t a i n e d by w r i t i n g t o t h e ~ u b l i c a t c o n s S e c t i o n , I n s t i t u t e f o r R e s e a r c h i n C o n s t r u c t i o n , N a t i o n a l R e s e a r c h C o u n c i l o f C a n a d a , O t t a w a , O n t a r i o , K 1 A 0R6. Ce document e s t d i s t r i b u 6 s o u s forme d e t i r 6 - 2 - p a r t p a r 1 ' I n s t i t u t de r e c h e r c h e e n c o n s t r u c t i o n . On p e u t o b t e n i r u n e l i s t e d e s p u b l i c a t i o n s d e 1 ' I n s t i t u t p o r t a n t s u r l e s t e c h n i q u e s ou l e s r e c h e r c h e s e n m a t i s r e d e b z t i m e n t e n B c r i v a n t il l a S e c t i o n d e s p u b l i c a t i o n s , I n s t i t u t d e r e c h e r c h e en c o n s t r u c t i o n , C o n s e i l n a t i o n a l d e r e c h e r c h e s du C a n a d a , O t t a w a ( O n t a r i o ) , K I A 0R6.