Air leakage performance of vertical sliding, double-hung and hinged windows for residential use

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Air leakage performance of vertical sliding, double-hung and hinged

windows for residential use

NATIONAL RESEARCH COUNCIL CANADA

DIVISION O F BUILDING RESEARCH

AIR LEAKAGE PERFORMANCE O F VERTICAL SLIDING, DOUBLE -HUNG AND HINGED WINDOWS

FOR RESIDENTIAL USE by

J . R . Sasaki

Internal Report No. 3 1 5 of the

D i v i s i o n of Building R e s e a r c h

Ottawa September 1 9 6 5

P R E F A C E

Information on the a i r leakage p e r f o r m a n c e of windows continues t o be of s o m e i m p o r t a n c e , f o r u s e in t h e a s s e s s m e n t of window p e r f o r m a n c e and in the e s t i m a t i o n of heating and cooling loads. R e s u l t s obtained on t h e a i r l e a k a g e p e r f o r m a n c e of r e sidential h o r i z o n t a l sliding windows c a r r i e d out a s p a r t of a p r o g r a m of window s t u d i e s w e r e p r e v i o u s l y r e p o r t e d . The s t u d i e s have now been extended t o include a n u m b e r of o t h e r t y p e s , the r e s u l t s f o r which a r e now r e p o r t e d .

T h e m a i n conclusions f r o m both of t h e s e s t u d i e s have a l r e a d y been published i n a p a p e r e n t i t l e d "Air Leakage Values f o r R e s i d e n t i a l Windows" by J. R. S a s a k i and A. G. Wilson.

T h i s w a s p r e s e n t e d a t the 72nd Annual Meeting of ASHRAE a t P o r t l a n d , J u l y 1965 and will a p p e a r i n ASHRAE T r a n s a c t i o n s P a r t 11 1965. T h e p r e s e n t r e p o r t , a s d o e s DBR R e p o r t No. 251, p r o v i d e s f u r t h e r d e t a i l s of the window c o n s t r u c t i o n s and of t h e r e s u l t s than was p o s s i b l e i n the paper.

The a u t h o r , a m e c h a n i c a l e n g i n e e r and a r e s e a r c h officer with the Building S e r v i c e s Section of the Division, i s i n c h a r g e of the window leakage s t u d i e s .

Ottawa, Ont.

,

S e p t e m b e r 1965

N. B. Hutcheon, A s s i s t a n t D i r e c t o r .

AIR LEAKAGE PERFORMANCE O F VERTICAL

SLIDING, DOUBLE-HUNG AND HINGED WINDOWS

F O R RESIDENTIAL USE

J . R . S a s a k i

A i r l e a k a g e m e a s u r e m e n t s of twenty-one hinged, v e r t i c a l s l i d i n g , and double-hung f a c t o r y - b u i l t windows f o r r e s i d e n t i a l u s e a r e r e p o r t e d . T h i s s e r i e s of t e s t s i s the second p a r t of a p r o g r a m u n d e r - t a k e n by t h e Division of Building R e s e a r c h t o i n v e s t i g a t e t h e a i r l e a k - a g e p e r f o r m a n c e of s o m e typical Canadian r e s i d e n t i a l windows p u r - c h a s e d in the p e r i o d , 1960-61. T h e f i r s t s e r i e s of t e s t s , on h o r i z o n t a l sliding windows, w a s r e p o r t e d in DBR I n t e r n a l R e p o r t No. 251. T h e p r e s e n t r e p o r t c o m p a r e s the l e a k a g e c h a r a c t e r i s t i c s of the t e s t windows with ( 1 ) a i r l e a k a g e c r i t e r i a f o r r e s i d e n t i a l windows e s t a b l i s h e d by the Canadian G o v e r n m e n t Specifications B o a r d a n d ( 2 ) d e s i g n v a l u e s f o r r e s i d e n t i a l windows s u g g e s t e d by the Guide of the A m e r i c a n Society of Heating, R e f r i g e r a t i n g and A i r Conditioning E n g i n e e e r s

.

The s o u r c e s of l e a k a g e a r e a l s o d e s c r i b e d .

DESCRIPTION O F T E S T WINDOWS

The twenty-one windows t e s t e d c a n be divided i n t o nine g r o u p s a c c o r d i n g to the m a t e r i a l of the s a s h and f r a m e :

( 1 ) E 1 t o E 3 - v e r t i c a l sliding and double -hung windows with wood s a s h and f r a m e ;

( 2 ) F 1 and F 2 - v e r t i c a l sliding and double-hung windows, wood f r a m e

,

a l u m i n u m

s a s h and t r a c k s ;

( 3 ) G1 and G2

-

double -hung windows, a l u m i n u m f r a m e , s a s h and t r a c k s ; ( 4 H1 - v e r t i c a l sliding windows, s t e e l f r a m e , s a s h and t r a c k s ; ( 5 ) K1 t o K4 - p r o j e c t e d windows, wood f r a m e and s a s h ; ( 6 ) L l - p r o j e c t e d windows, a l u m i n u m f r a m e and s a s h ;

( 7 )

M1

t o M4

-

c a s e m e n t windows, wood f r a m e and s a s h ; ( 8 ) N1 and N2 - c a s e m e n t windows, a l u m i n u m f r a m e and s a s h ; ( 9 ) P 1 and P 2 - c a s e m e n t windows, s t e e l f r a m e and s a s h .

T h e v e r t i c a l sliding and double-hung windows of grouFs ( 1 ) t o (4) a r e d e s c r i b e d in Table I. T h e s a s h of the double-hung window i s a t t a c h e d t o the f r a m e by s o m e f o r m of balance device s u c h a s a c o u n t e r - weight, a s p i r a l - s p r i n g o r a s p r i n g -wound t a p e ; the s a s h in a sliding window i s held open e i t h e r by f r i c t i o n of t h e s a s h i n the t r a c k s o r by s a s h - m o u n t e d lock pins that engage holes along the jamb t r a c k s . Windows F 1 , F 2 , G1 and G2 a r e double windows with n e a r l y identical i n n e r and o u t e r o p e r a t i n g units; window H1 i s a single window; and windows E l and E 2 a r e b a s i c a l l y single windows equipped with s t o r m u n i t s . T h e d e t a i l s of t h e v e r t i c a l sliding and double-hung window t y p e s a r e shown in F i g u r e s 1 t o 7 .

The p r o j e c t e d and c a s e m e n t windows a r e d e s c r i b e d in T a b l e 11. All the windows of g r o u p s ( 5 ) t o ( 9 ) a r e single windows, but the wood p r o j e c t e d and c a s e m e n t windows a r e provided with r e - movable glazing units, with light a l u m i n u m s u r r o u n d s , a t t a c h e d t o t h e o p e r a t i n g s a s h . T h e light a l u m i n u m s a s h o r glazing unit d o e s not have the s t r e n g t h r e q u i r e d of a full -weight a l u m i n u m r e s i d e n t i a l window s a s h in CGSB Specification 6 3 - G P - 3 . I t s p r i m a r y function i s t o p r o - t e c t the g l a s s edge f r o m chipping and t o c a r r y the h a r d w a r e and w e a t h e r - s t r i p p i n g ; it a d d s l i t t l e r i g i d i t y o r s t r e n g t h t o the g l a s s . The four wood p r o j e c t e d windows a r e bottom-outswinging awning t y p e s ; the a l u m i n u m p r o j e c t e d window i s a s i d e -outswinging unit. All the c a s e m e n t windows a r e side-hinged outswinging u n i t s . T h e d e t a i l s of t y p i c a l wood p r o - jected and c a s e m e n t windows a r e shown in F i g u r e s 8 and 9. D e t a i l s of t h e a l u m i n u m and s t e e l c a s e m e n t windows a r e shown in F i g u r e s 10 t o 12.

APPARATUS AND TEST PROCEDURE

T h e t e s t s w e r e p e r f o r m e d in t h e DBR window a i r l e a k a g e a p p a r a t u s ( F i g u r e 1 3 ) . It c o n s i s t s of two a i r - t i g h t boxes with p r o v i s i o n f o r mounting the window between t h e m in a n a i r - t i g h t panel. A i r i s

supplied t o the high p r e s s u r e c h a m b e r f r o m a d - c m o t o r - d r i v e n blower. C a l i b r a t e d o r i f i c e m e t e r s a r e mounted on the r e a r wall of the m e t e r i n g c h a m b e r . As the c h a m b e r s a r e s e a l e d t o the mounting p a n e l , t h e a i r supplied t o the p r e s s u r e c h a m b e r flows through t h e window into t h e m e t e r i n g c h a m b e r , then through the f l o w m e t e r t o t h e r o o m . T h e flow of a i r m e a s u r e d a t t h e o r i f i c e m e t e r i s nominally equal t o t h e flow of

a i r that p a s s e s through the window. P e r f e c t sealing i s n e v e r achieved, however, and the extraneous leakage f r o m the m e t e r i n g box m u s t be d e t e r m i n e d before the t e s t and accounted f o r in the calculation of the window a i r leakage.

The window under t e s t was mounted in the panel, with sealing between the panel and moulding along the e x t e r i o r f a c e of the window f r a m e only. The s a s h and lock adjustments a s well a s any other 'alternations to the window configuration w e r e m a d e and the a i r supply t o the high p r e s s u r e c h a m b e r v a r i e d t o give the r e q u i r e d p r e s s u r e difference a c r o s s the window. The resulting p r e s s u r e difference

a c r o s s the o r i f i c e m e t e r w a s then m e a s u r e d . T h i s p r o c e d u r e was r e - peated in e a c h t e s t f o r approximately eight values of a i r p r e s s u r e

difference ranging f r o m 0. 10 t o 0.79 in. w a t e r gauge (wg) corresponding t o the stagnation p r e s s u r e f o r wind s p e e d s of 15 t o 40 mph.

The method u s e d t o calculate the window a i r leakage

value is shown in Appendix A, which a l s o includes a table of stagnation p r e s s u r e s f o r v a r i o u s wind speeds.

TEST CONDITIONS AND RESULTS

The r e s u l t s of the a i r leakage t e s t s a r e shown in F i g u r e s 14 to 17, and a r e summ,arized in T a b l e s 111 and IV. The a i r leakage values listed in the t a b l e s and quoted e l s e w h e r e in the r e p o r t c o r r e s p o n d to a window p r e s s u r e difference of 0. 30 in. wg (1. 56 lb/sq f t ) , the total

stagnation p r e s s u r e equivalent of a 25 mph wind. T h i s value of p r e s s u r e difference i s commonly used in Canada and the U. S. A. f o r the c o m - p a r i s o n and specification of window a i r t i g h t n e s s .

P r i m e Unit Air Leakage

The p r i m e unit a i r leakage v a l u e s w e r e obtained with the p r i m e o r inner operating unit of t h e window locked and t h e s t o r m o r o u t e r operating unit, if any, open. T h i s i s the window t e s t configuration r e q u i r e d f o r double windows by the CGSB specifications. The p r i m e unit leakage is the m o s t convenient value t o u s e when comparing the p e r f o r m a n c e of different window units.

The p r i m e unit leakage c h a r a c t e r i s t i c s of the double -hung and v e r t i c a l sliding windows a r e shown i n F i g u r e 14 and the c h a r a c t e r

-

i s t i c s of the projected and c a s e m e n t windows in F i g u r e 15. T-he CGSB a i r leakage c r i t e r i o n f o r r e s i d e n t i a l windows, 3/4 cu ft/(min)(ft of s a s h c r a c k ) a t a window p r e s s u r e difference of 0.30 in. wg, is shown in both f i g u r e s f o r c o m p a r i s o n .

Windows F 2 , G1, G2, H1 and K1, KZ, K 3 , L 1 , M1, M2, N2 m e t t h e CGSB air l e a k a g e l i m i t without m o d i f i c a t i o n s .

ASHRAE Configuration

T h e Guide of the A m e r i c a n S o c i e t y of Heating, R e f r i g e r a t i n g and A i r Conditioning E n g i n e e r s g i v e s a i r l e a k a g e v a l u e s f o r v a r i o u s window t y p e s f o r u s e in calculating building heating and a i r conditioning l o a d s . Values f o r double-hung, s i n g l e wood windows and f o r s t e e l c a s e m e n t windows a r e given. T h e Guide a l s o s u g g e s t s t h a t t h e desi.gn v a l u e s f o r a v e r a g e -fit double -hung windows a r e a p p r o p r i a t e f o r wood c a s e m e n t windows.

Guide d e s i g n v a l u e s w e r e obtained in t e s t s i n which the double-hung windows w e r e c l o s e d but unlocked and the hinged windows w e r e locked. T h e s e configurations w e r e a s s u m e d t o be t h o s e n o r m a l l y found on a building. T h e c o m p a r a b l e s a s h configuration f o r n o r m a l o p e r a t i o n of double windows w a s a s s u m e d t o be with both the o u t e r ( s t o r m ) unit and i n n e r ( p r i m e ) unit c l o s e d but unlocked, e x c e p t when locking o c c u r r e d a u t o m a t i c a l l y .

All the double-hung and v e r t i c a l sliding windows, with the exception of G2, w e r e t e s t e d with t h e ASHRAE configuration. T h e r e s u l t s a r e c o m p a r e d with the ASHRAE d e s i g n v a l u e s f o r wood d o u b l e - hung windows ( F i g u r e 1 6 ) . T h e ASHRAE v a l u e s shown i n F i g u r e 16 have been modified f r o m t h e Guide t a b l e v a l u e s by excluding the

a d j u s t m e n t s f o r l e a k a g e between window f r a m e and wall and f o r p r e s s u r e build-up in the building.

T h e ASHRAE configuration f o r hinged windows i s the s a m e a s t h a t u s e d t o d e t e r m i n e the p r i m e unit a i r l e a k a g e . L e a k a g e v a l u e s f o r wood c a s e m e n t and p r o j e c t e d windows a r e a l s o shown in F i g u r e 16. T h e v a l u e s f o r t h e m e t a l c a s e m e n t and p r o j e c t e d windows a r e c o m p a r e d with the ASHRAE d e s i g n v a l u e s f o r r e s i d e n t i a l s t e e l c a s e m e n t windows in F i g u r e 17.

With t h e exception of window E 3 , all t h e sliding windows and wooden hinged windows w e r e a t l e a s t p a r t i a l l y w e a t h e r s t r i p p e d . L e a k a g e v a l u e s r a n g e d f r o m just above t h e ASHRAE v a l u e s f o r p o o r - f i t w e a t h e r s t r i p p e d , double -hung windows down t o v a l u e s well below t h o s e f o r a v e r a g e -fit weathe r s t r i p p e d windows. T h e l e a k a g e c h a r a c t e r

-

i s t i c f o r the n o n - w e a t h e r s t r i p p e d double-hung window, E3, coincided well with the ASHRAE value f o r t h e p o o r - f i t , n o n - w e a t h e r s t r i p p e d , d o u b l e - hung window. T h e s e r e s u l t s indicate t h a t the Guide d e s i g n v a l u e s c a n be applied t o sliding and wooden hinged windows in c u r r e n t u s e .

T h e t e s t r e s u l t s f o r m e t a l . hinged windows w e r e not

c o n s i s t e n t with t h e v a l u e s given in the ~ u i d e . T h e t h r e e w e a t h e r s t r i p p e d windows l e a k e d m o r e than t h e two n o n - w e a t h e r s t r i p p e d windows;

l e a k a g e v a l u e s f o r t h e l a t t e r w e r e m u c h l o w e r than the ASHRAE value f o r a v e r a g e - f i t , n o n - w e a t h e r s t r i p p e d , s t e e l c a s e m e n t windows. T h e r e s u l t s d e m o n s t r a t e the e f f e c t on a i r t i g h t n e s s of a good s a s h - t o - f - a m e f i t and good locking h a r d w a r e . T h e a i r l e a k a g e r e s u l t s obtained f o r t h e t h r e e w e a t h e r s t r i p p e d m e t a l windows cannot be c o n s i d e r e d r e p r e -

s e n t a t i v e b e c a u s e t h e y w e r e f r o m a s i n g l e m a n u f a c t u r e r . T h e value of w e a t h e r s t r i p p i n g on m e t a l p r o j e c t e d a n d c a s e m e n t windows and t h e a p p l i c a b i l i t y of Guide d a t a t o c u r r e n t m e t a l hinged windows cannot be d e t e r m i n e d on t h e b a s i s of t h e l i m i t e d e x p e r i m e n t a l e v i d e n c e obtained on t h i s type of window.

L e a k a g e S o u r c e s

I n f i l t r a t i o n t e s t s w e r e p e r f o r m e d on a l l the windows with s o m e of t h e following t e s t c o n f i g u r a t i o n s in o r d e r t o d e t e r m i n e the a m o u n t of l e a k a g e o c c u r r i n g a t the v a r i o u s l e a k a g e s o u r c e s .

( i ) i n n e r unit locked - s t o r m o r o u t e r unit, if a n y , open; ( i i ) c o n f i g u r a t i o n ( i ) with head t r a c k s e a l e d ;

( i i i ) c o n f i g u r a t i o n ( i i ) with s i l l t r a c k s e a l e d ; ( i v ) configuration ( i i i ) with j a m b t r a c k s s e a l e d ;

( v ) configuration ( i v ) with m e e t i n g r a i l s e a l e d ( s l i d e r s ) , o r corlfiguration ( i v ) with h i n g e s s e a l e d ;

( v i ) configuration ( v ) with f r a m e f a c e moulding (if a n y ) s e a l e d . V e r t i c a l Sliding and Double -Hung Windows - Wood

T h e p r i m e unit a i r l e a k a g e r a t e of a l l t h r e e wood s l i d e r s e x c e e d e d t h e CGSR l i m i t . T h e m a j o r s o u r c e of l e a k a g e f o r window E l w a s the f r a m e moulding. L e a k a g e a r o u n d t h e s a s h p r o p e r w a s r e l a t i v e 1 s m a l l and e v e n l y d i s t r i b u t e d . T h e f a c e moulding of

EZ

w a s a l s o a l a r g e l e a k a g e s o u r c e , but a l a r g e r one w a s a r o u n d t h e j a m b t r a c k s . T h i s window had s p r i n g - t e n s i o n e d light a l u m i n u m t r a c k s s e t in the wood f r a m e ; t h e t r a c k s w e r e not w e a t h e r s t r i p p e d . L e a k a g e

occ:urrerl t h r o u g h the c r a c k s betw?en s a s h a n d t r a c k s a s w e l l a s t h r o u g h c r a c k s between t r a c k s and f r a m e . Window E3, which had a l e a k a g e r a t e e x c e e d i n g f o u r t i m e s t h e r n a x i m u m p e r m i s s i b l e r a t e , w a s badly

c:onstructed f o r a i r t i g h t n e s s . T h e f i t of thc s a s h in t h e t r a c k s and framct w a s p o o r , the m e e t i n g r a i l lock w a s i n e f f e c t i v e , and w e a t h e r - s t r i p p i n g w a s not p r o v i d e d .

V e r t i c a l Sliding and Double -Hung Windows - M e t a l

All t h e m e t a l s l i d i n g windows e x c e p t F 1 m e t the CGSB c r i t e r i a f o r a i r t i g h t n e s s . M e t a l s l i d i n g s a s h e s m u s t be m a d e t o f i t l o o s e l y in t h e t r a c k s in o r d e r t o p e r m i t e a s e of o p e r a t i o n ; w e a t h e r - s t r i p p i n g i s t h e r e f o r e n e c e s s a r y t o e n s u r e a i r ' l i g h t n e s s . Without e x c e p t i o n , a l l t h e windows in t h e g r o u p w e r e w e a t h e r s t r i p p e d . T h e j a m b t r a c k s and m e e t i n g r a i l s w e r e n o r m a l l y the w o r s t l e a k a g e s o u r c e s , but w h e r e t h e y i n t e r s e c t e d w e a t h e r s t r i p p i n g w a s a l s o d i f f i c u l t . Insufficient c l o s i n g p r e s s u r e a t the m e e t i n g r a i l s w a s t h e m a i n c a u s e of a i r l e a k a g e a t t h i s point. A n o t h e r s o u r c e w a s t h e f r a m e which, being f a b r i c a t e d f r o m m a n y s e p a r a t e m e t a l s e c t i o n s , p r e s e n t e d s e a l i n g d i f f i c u l t i e s . Window F 1 , which had a l a r g e f r a m e l e a k a g e had a wood f r a m e with a n e x t e r i o r cladding of a l u m i n u m . A i r w a s a b l e t o p a s s t h r o u g h t h e c r a c k s i n t h e m e t a l c l a d d i n g , a r o u n d t h e wood f r a m e and l e a k t o the i n s i d e .

Hinged Windows

-

Wood

T h e f o u r wood p r o j e c t e d windows and c a s e m e n t windows M1 and M2 m e t t h e CGSB c r i t e r i o n f o r a i r t i g h t n e s s . E x c e p t f o r K 2

and M2, a l l t h e wood windows had v e r y l a r g e f r a m e moulding l e a k a g e , but when t h i s w a s e l i m i n a t e d , a l l t h e wood hinged windows m e t t h e a i r t i g h t n e s s r e q u i r e m e n t . C a s e m e n t w i n d o w s , M2 and M4, w i t h c l o s e h i n g e s had r e l a t i v e l y l a r g e r l e a k a g e s t h a n had M1 and M3, which had extended h i n g e s ; w e a t h e r s t r i p p i n g a r o u n d t h e s a s h i s p r o b a b l y s i m p l i

-

f i e d with e x t e n d e d h i n g e s .

Hinged Windows

-

Metal

Of t h e five m e t a l hinged windows t e s t e d , only L1 and N2 m e t t h e a i r t i g h t n e s s r e q u i r e m e n t . Both- windows w e r e n o n - w e a t h e r

-

s t r i p p e d , but the f i t of t h e s a s h in t h e f r a m e w a s good and t h e l o c k s w e r e v e r y e f f e c t i v e . The m a x i m u m m e a s u r e d c l e a r a n c e between s a s h and f r a m e w a s 0 . 0 1 5 i n . and w a s m e a s u r e d on window N2 along t h e hinge j a m b . Windows N1, P1 and P 2 w e r e w e a t h e r s t r i p p e d , but f a i l e d t o m e e t t h e a i r t i g h t n e s s r e q u i r e m e n t . T h e w e a t h e r s t r i p p i n g p r o v i d e d w a s e i t h e r t o o s m a l l o r p o o r l y p o s i t i o n e d t o c o m p e n s a t e f o r t h e l a r g e c l e a r a n c e between s a s h and f r a m e . T h e h i n g e - j a m b c l e a r a n c e of window P 2 w a s a s l a r g e a s 0 . 0 8 5 in.

E x f i l t r a t i o n v a l u e s (for a i r flow f r o m i n s i d e to o u t s i d e ) a r e given in T a b l e s III and IV a s a p e r c e n t a g e of p r i m e unit infil- t r a t i o n v a l u e s and w e r e d e t e r m i n e d with the s a m e s a s h configurations. T h e e x f i l t r a t i o n v a l u e s f o r t h e w e a t h e r s t r i p p e d windows, with t h e exception of K 2 , d i f f e r e d f r o m t h e i n f i l t r a t i o n v a l u e s by n o m o r e than

30 p e r cent. T h i s i n d i c a t e s t h a t locking l i m i t e d the s a s h m o v e m e n t , o r that t h e effect of s a s h m o v e m e n t w a s c o m p e n s a t e d f o r by w e a t h e r

-

stripping. T h e r a t i o of e x f i l t r a t i o n t o i n f i l t r a t i o n f o r K2 i s apparerttly l a r g e b e c a u s e of t h e exceptionally low infiltration. T h e r e l a t i v e l y

l a r g e e x f i l t r a t i o n t h r o u g h N2 would b e e x p e c t e d of a n o n - w e a t h e r s t r i p p e d , outswinging, hinged window b e c a u s e of t h e tendency of t h e p r e s s u r e t o push t h e s a s h away f r o m the f r a m e . Window L 1 , which w a s s i m i l a r in

d e s i g n , showed an e x f i l t r a t i o n r a t e only slightly g r e a t e r t h a n t h e i n f i l - t r a t i o n r a t e , probably indicating v e r y effective locking.

L o c k and S a s h Confieuration

T h e two single sliding windows with s t o r m u n i t s , E l and E 2 , and the f o u r double windows, F 1, F 2 , G1 and G2, w e r e t e s t e d with

s o m e o r a l l of the following configurations:

( i ) i n n e r unit c l o s e d and unlocked

-

o u t e r unit open; ( i i ) i n n e r unit locked

-

o u t e r unit open; ( i i i ) i n n e r unit locked

-

o u t e r unit locked;

( i d i n n e r unit open

-

o u t e r unit locked. Configurations ( i ) and ( i i ) i n d i c a t e the e f f e c t i v e n e s s of t h e lock on the i n n e r o r p r i m e unit. V e r t i c a l sliding windows, E 1 and F 2 , could not be t e s t e d in t h e unlocked configuration s i n c e the l o c k s

engaged upon closing. T h e l o c k s on windows E 2 and G1, both c a m - t y p e l o c k s mounted on t h e m e e t i n g r a i l , did n o t i n c r e a s e window t i g h t n e s s . T h e l o c k s on windows F 1 and GZ, h o w e v e r , r e d u c e d leakage by a s m u c h a s 70 p e r cent.

Configurations ( i i ) and ( i i i ) i n d i c a t e t h e r e d u c t i o n i n o v e r - a l l window l e a k a g e effected by closing and locking t h e o u t e r o r s t o r m unit. T h e l e a k a g e t h r o u g h windows E 2 , F 1 and F 2 w a s noticeably d e c r e a s e d by t h e s t o r m unit, w h e r e a s t h e l e a k a g e t h r o u g h E l and G1 w a s only slightly r e d u c e d . R e s i s t a n c e t o condensation between p a n e s and t o r a i n 1,enetration r e q u i r e s a n i n n e r o r p r i m e unit m a n y t i m e s t i g h t e r t h a n t h e o u t e r o r s t o r m unit. T o e n s u r e t h i s d e g r e e of i n n e r s a s h t i g h t n e s s t h e CGSA window s p e c i f i c a t i o n s s t a t e t h a t the a i r t i g h t -

n e s s r e q u i r e m e n t m u s t be m e t by the p r i m e unit alone.

COMMENTS AND CONCLUSIONS

The following f a c t o r s d e t e r m i n e the initial a i r tightness of windows:

(1) design and workmanship in fabrication;

( 2 ) fit of the s a s h in the t r a c k o r f r a m e ;

( 3 ) design, position and installation of weather stripping;

( 4 ) design and adjustment of the lock.

The p r e s e n t s e r i e s of t e s t s d e m o n s t r a t e s how window a i r tightness s u f f e r s when t h e s e f a c t o r s a r e not given adequate consideration.

Following a r e s o m e c o m m e n t s on the a i r tightness of the hinged, v e r t i c a l sliding, and double -hung windows that w e r e tested:

(1) F a c t o r y -built, non-weather s t r i p p e d , wood double -hung windows, such a s E3, will probably not m e e t the

specification a i r tightness r e q u i r e m e n t u n l e s s the

design and workmanship in fabrication a r e exceptionally good.

Spring-tensioned aluminum jamb t r a c k s used in double

-

hung wood windows ( s u c h a s E 2 and E 3 ) introduce

additional leakage s o u r c e s in providing e a s e of s a s h r e m o v a l , and a r e not a s a t i s f a c t o r y substitute f o r w e a t h e r s t r i p p i n g .

Aluminum cladding applied t o the e x t e r i o r face of the wood window f r a m e , a s in window F 1 , m u s t be

carefully s e a l e d t o avoid e x c e s s i v e f r a m e leakage.

Effectiveness of the s a s h lock b e c o m e s i n c r e a s i n g l y i m p o r t a n t a s the quantity of applied weatherstripping d e c r e a s e s .

Weatherstripping f o r v e r t i c a l sliding and double -hung windows should be located along the i n n e r m o s t sealing

s u r f a c e on the upper s a s h and along the o u t e r m o s t sealing s u r f a c e on the lower s a s h t o prevent a i r penetration up along the jamb t r a c k s .

When the v e r t i c a l s a s h edges of double-hung windows, such a s

F1

and GZ, a r e h a r e g l a s s , they should s i t well inside the jamb t r a c k s ; otherwise the edges will jump out of the t r a c k s onto the weatherstripping and damage t h e weather stripping, making s a s h operation difficult and possibly chipping g l a s s .

Wood projected and c a s e m e n t windows a r e s a t i s f a c t o r i l y a i r tight provided that c a r e i s taken t o e n s u r e a tight f r a m e construction.

The p r i m a r y a i m in t h e design of hinged m e t a l windows should be t o obtain a good fit of the s a s h in the f r a m e and to provide a lock capable of exerting a positive closing p r e s s u r e . Only when the fit and locking of t h e s a s h a r e not s a t i s f a c t o r y d o e s weatherstripping become absolutely n e c e s s a r y . T h i s i s d e m o n s t r a t e d by the tightness exhibited by windows L1 and N2, both non- weather stripped.

h

g e n e r a l , the a i r leakage c h a r a c t e r i s t i c s of hinged

windows w e r e m o r e affected by t h e d i r e c t i o n of a i r flow than w e r e sliding windows.

Air leakage t e s t s using t e s t configurations c o m p a r a b l e t o t h o s e used t o obtain the ASHRAE Guide values would indicate that the ASHRAE window design a i r leakage r a t e s f o r wood double-hung windows can be used f o r r e s i d e n t i a l double-hung, v e r t i c a l sliding, and wooden hinged windows. B e c a u s e of insufficient d a t a , a s i m i l a r s t a t e m e n t cannot be made concerning m e t a l hinged

windows

.

ACKNOWLEDGEMENT

The author wishes t o acknowledge the a s s i s t a n c e of

TABLE 1 VERTICAL SLIDING AND DOUBLE-HUNG WINDOWS

- Identification P r i m e Unit Openinn Description

(Width x ~ e i ~ h t ) -- . . . .

E 1 39.x 49 in. Single Vertical Sliding window with attached wood s t o r m unit; two sliding wood p r i m e s a s h e s , two light aluminum LC = 17.9 f t panels sliding in s t o r m unit; wood main f r a m e with face moulding and blind stops; spring-type aluminum w/s

attached t o upper p r i m e s a s h meeting r a i l and t o lower p r i m e s a s h sill r a i l , no w/s around s t o r m unit; jamb r a i l p r e s s u r e - s t r i p p r i m e s a s h positioners; cam-type lock on p r i m e sash.

EZ 40 x 55 in. Single Double-Hung window with attached wood s t o r m unit; two sliding wood p r i m e s a s h e s hung on spiral-spring LC = 19.2 ft balances, two non-sliding removable wood s t o r m s a s h e s hung on main f r a m e : wood f r a m e with light aluminum

spring jamb t r a c k s and f a c e moulding along the head, s i l l and jamb f r a m e m e m b e r s ; spring-type bronze w/s attached along p r i m e head f r a m e m e m b e r , upper p r i m e s a s h meeting r a i l and lower p r i m e s a s h s i l l r a i l ; can-type lock on p r i m e s a s h .

39 x 53: in. Single Double-Hung window; two wood sliding s a s h e s hung on s p i r a l spring balances; wood f r a m e with light aluminum LC = 18.8 f t _{spring jamb t r a c k s and face moulding along head and jamb m e m b e r s ; no w/s; cam-type lock on s a s h .}

379 x 53$ in. Double Double-Hung window; two p r i m e and two s t o r m sliding s a s h e s hung on s p i r a l spring balances, each s a s h LC = 1 8 . 3 f t having only light aluminum horizontal r a i l s ; wood f r a m e with aluminum capping on e x t e r i o r and aluminum p r i m e

and s t o r m t r a c k s ; f o a m plastic w/s along head t r a c k and spring-type s t a i n l e s s s t e e l along jamb t r a c k s of both s t o r m ar.d p r i m e units; cam-type locks on both inner and outer unit.

3 6 x 5C 3/4 in. Double Vertical Sliding window; two p r i m e and two s t o r m light aluminum sliding s a s h e s , maintained in open o r LC = 17.5 ft closed position by the engagement of s a s h lock pins into holes in the jamb t r a c k s ; wood m a i n - f r a m e with

aluminum s i l l , head and jamb t r a c k s attached to inner and outer f r a m e face; wool pile w/s along jamb and head s a s h r a i l s , and vinyl p l a s t i c w/s along meeting r a i l s of both inner and outer units.

399 x 54 in. Douhle Double-Hung window; two p r i m e and two s t o r m sliding aluminum s a s h e s , hung on spring-loaded tape balances; L C = 18.9 ft aluminum s t o r m and p r i m e f r a m e s separated by a rigid vinyl t h e r m a l b r e a k ; one jamb t r a c k of each s a s h h a s a

foam rubber cushion permitting the removal of the s a s h e s for cleaning, wool pile w/s attached t o a l l jamb t r a c k s and t o the upper p r i m e s a s h meeting r a i l ; and vinyl plastic w/s attached t o the p r i m e head and sill t r a c k s , and to the p r i m e and s t o r m s i l l r a i l s ; cam-type lock on p r i m e unit only.

3 9 i x 54; in. Double Double-Hung window; two p r i m e and two s t o r m sliding s a s h e s hung on s p i r a l - s p r i n g balances, each s a s h L C = 18.9 ft having only aluminum horizontal r a i l s ; aluminum s t o r m and p r i m e f r a m e s s e p a r a t e d by a rigid vinyl t h e r m a l

break; felt w/s along head and sill t r a c k s and along upper s a s h meeting r a i l s of both s t o r m and p r i m e units; sprixg-type s t a i n l e s s s t e e l w / s along a l l jamb t r a c k s ; sliding wedge-type lock on both units.

3 6 i x 5 0 i in. Single Vertical Sliding window; sliding lower and stationary upper tub-alar sheet steel s a s h e s ; lower s a s h positioned LC = 17.5 ft by s a s h lock pin engaging holes in jambs and upper s a s h held stationary by s c r e e n ; tubular sheet s t e e l f r a m e

and t r a c k s ; wool pile w/s attached to head and jamb r a i l s of both s a s h e s a r d t o the jamb t r a c k s of lower s a s h ; vinyl w/s attached t o meeting rail.

TABLE I1 PROJECTED AND CASEMENT WINDOWS - . .

ldentification P r i m e Unit Opening Description (Width x Height)

K 1 4 7 i x 32 3/4 i n . Single P r o j e c t e d window; one wood s a s h , bottom outswinging, with light aluminum removable glazing unit attached L C = 1 3 . 6 f t t o outer f a c e ; wood f r a m e with blind stop and face moulding along jamb and head m e m b e r s ; friction s a s h

a d j u s t e r t r a c k s attached t o jamb m e m b e r s ; spring-type aluminum w/s applied t o head and jamb f r a m e m e m b e r s and t o s a s h s i l l r a i l s : bar-type u n d e r s c r e e n operator/lock.

46; x 29 3/4 i n . Singie P r o j e c t e d window; one wood s a s h , bottom outswinging, with light aluminum removable glazing unit attached L C = 1 2 . 7 f t _{t o inside face and with 2 i - i n . holes in s i l l r a i l venting to outside; wood f r a m e with f r i c t i o n s a s h a d j u s t e r t r a c k s}

attached t o jamb m e m b e r s ; spring-type s t a i n l e s s s t e e l w/s along jamb f r a m e m e m b e r s and s a s h s i l l and head r a i l s : vinyl w / s around removable glazing unit; b a r - t y p e u n d e r s c r e e n operator/lock.

40f x 24 ~ n . Single P r o j e c t e d window: one wood s a s h , bottom outsuringing , with light aluminum removable glazing unit attached to

LC = 10.7 ft outer f a c e : wood f r a m e with face moulding along head and jamb m e m b e r s and with a wood sub-sill; friction s a s h a d j u s t e r t r a c k s attached t o jamb m e m b e r s ; spring-type aluminum applied t o head, s i l l and jamb s a s h r a i l s ; u n d e r s c r e e n roto-operator/lock.

48 x 2 5 in. Single P r o j e c t e d window; s a s h a r r a n g e m e n t s i m i l a r t o K2 and f r a m e a s s e m b l y s i m i l a r t o K3; spring-type aluminum L C = 1 2 . 2 ft w/s applied t o head, s i l l and jamb f r a m e m e m b e r s ; vinyl w/s around removable glazing unit; two cam-type

locks mounted on operating s a s h .

j 0 * x 26r in. Single P r o j e c t e d window; one aluminum s a s h , bottom outswinging; aluminum f r a m e with 1:-in. hole draining f r a m e LC = 12.8 ft s i l l ; no w / s ; two cam-type locks mounted on operating s a s h .

21 x 49 in. Single C a s e m e n t window; one wood s a s h , side-hung on extended hinges, with a light aluminum removable glazing unit L C = 11.: ft attached t o i n n e r face and with I + - m . hole a t top of one jamb r a i l and l f -in. hole at.bottom of other jamb r a i l

venting t o outside; wood f r a m e with blind s t o p and f a c e moulding along head and jamb m e m b e r s , and blind s t o p along s i l i m e m b e r ; spring-type aluminum w / s applied t o head and jamb f r a m e m e m b e r s , and t o s a s h s i l l r a i l ; aiuminum w/ s around removable unit; u n d e r s c r e e n r o t o - o p e r a t o r and two positive p r e s s u r e locks.

23 x 52 in. Fingle Casement window; one wood s a s h , side-hung on close hinges, with a light aluminum removable qlazing unit LC = 12.5 f t attached t o i n n e r f a c e ; s t e e l f r a m e with wood i n n e r lining; spring-type s t a m l e s s s t e e i w / s attached t o head,

TABLE 11 (Cont'd)

!

i Identification P r i m e Unit Opening Description

I

(Width x Height)

M 3 21 x 481 in. Similar t o M1, except f o r absence of blind stops around f r a m e and r e p l a c e m e n t of w/s around removable glazing L C = 1 1 . 6 f t unit with vinyl w/ s

.

i

M4 23 x 43 in. Single C a s e m e n t window; one wood s a s h , side-hung on close hinges, with a light aluminum removable glazing unir L C = 11.0 ft attached t o i n n e r f a c e ; and with 2 i - i n . holes i n s i l l r a i l venting t o outside; wood f r a m e with face moulding

along head and jamb m e m b e r s and with a wood sub-sill; spring-type bronze w/s along e n t i r e f r a m e opening p e r i m e t e r ; vinyl w/s around removable unit; cam-type hook jamb lock.

21 x 44 in. Single C a s e m e n t window; one aluminum s a s h , side-hung on close hinges; aluminum f r a m e ; f u l l - p e r i m e t e r vinyl

LC = 1 0 . 9 f t w / s attached t o f r a m e opening; roto-operator and cam-type lock.

20f x 50) in. Single C a s e m e n t window; one aluminum s a s h , side-hung on extended hinges; aluminum f r a m e with 3 3/16-in. holes LC = 11.9 ft along inner s i l l , draining t o outside; no w j s ; s a m e o p e r a t o r and lock a s N1.

2 1 i x 4 6 in. Single C a s e m e n t window; one s t e e l s a s h , side-hung on extended hinges; s t e e l f r a m e ; spring-type aluminum w/s L C = 11.1 i t attached t o all f r a m e m e m b e r s along inner sealing lip; u n d e r s c r e e n roto-operator and hook-type lock. 2 1 i x 46 in. Identical t o P 1 , except f r a m e w/s replaced by vinyl w/s attached t o inside s c r e e n which i s p r e s s e d against both

TABLE LZI ALR LEAKAGE TEST RESULTS - VERTICAL SLIDING AND DOUBLE-HUNG WINDOWS (CFM/FT AND P E R CENT AT hw = 0.30 INCH WATER)

I P r i m e Unit Leakage

-

As received

- F r a m e face moulding s e a l e d

II ASHRAE Configuration Leakage

LII Distribution Of Leakage (% of p r i m e leakage

-

a s r e c e i v e d ) F r a m e

-

Total - Moulding Head t r a c k Sill t r a c k J a m b t r a c k s Meeting r a i l IV Exfiltration (% of p r i m e leakage

-

a s r e c e i v e d ) V Lock and S a s h Configuration (% of p r i m e leakage

- a s r e c e i v e d ) P r i m e unlocked

-

S t o r m open P r i m e locked - S t o r m open P r i m e locked

-

S t o r m locked P r i m e open

-

S t o r m locked WOOD WINDOWS E 1 E 2 E 3 0.80 1.61 3.40 0.43 1.11 3.11 0.76 1.19 3.40 64% 37% 12% 4 6 3 1 9 14 9 7 7 1 5 3 1 6 3 7 23 9 2 27 107% 102% 100% 100% 100 96 7 5

METAL AND METAL-WOOD WINDOWS

F 1 F 2 G1 G 2 H 1 1.07 0.47 0.35 0.75 0.72 1 . 1 8 0.30 0.32 0.72 50% 40% 20% 31% 47% 4 11 1 5 1 1 6 8 1 9 1 5 30 33 7 2 9 2 5 11 4 5 48 22 100% 108% 106% 93% 74% 175% 100% 165% 100 100% 100 100 60 64 94 66 119

r

PLASTIC GUIDE ,,,--WOOD STORM SASH WOOD FRAME SASH RETAINER .UMINUM STRIP BLIND OU TStUE /NS#]E FACE MOULDING REMOVABLE LIGHT ALUMINUM STORM _---

PANEL WOOD PRIME SASH

7 SASH LOCK ALUMINUM CROSS BAR ALUMINUM w/(i

FIGURE I DETAILS OF WINDOW E - l HEAD

-

MEETING RAIL SILL

-

ALUMINUM TRACK -SPIRAL SPRING SASH BALANCE OUTSIDE

n

FIGURE 2 DETAILS OF WINDOW E - 2 JAMBS MEETING RAIL

WOOD FRAME

ALUMINUM

@

:

I

JAMBS

ALUMINUM FACING TRACKS

ours/oE

CAM TYPE LOCK

LIGHT ALUMINUM SASH ALUMINUM FLASHING

MEETING RAIL

FIGURE 3

WOOD FRAME

-'I

STORM PRIME UNIT

UNlT

LIGHT ALUMINUM SASH

FIGLIRE 4

ALUYINUY SASH ALUMINUM FRAME JAMBS WOOL PILE W/S OVERHEAD SASH HEAD

-

VINYL W/S 1 CAM - TYPE LOCK WOOL PILE W/S MEETING &-+. -FIGURE 5 DETAILS OF WINDOW G- l

STAINLESS STEEL W/S

-RIGID VINYL THERMAL BREAK

JAMBS

HEAD

-

SLIDING SASH LOCK

MEETING RAIL

FELT w/S

LIGHT ALUMINUM SASH 1111

FIGURE 6

OUTSIDE HEAD

-

MEETING RAIL SILL

-

WOOL INSIDE

-

STEEL STEEL PlLE LlDlNC SASH LOCK FIGURE 7 DETAILS OF WINDOW H - l

I I

/WOOL PILE W/S

-

OUTSIDF

JAMB

FACE MOULDING FRICTION ADJUSTOR FRICTION ADJUSTOR REMOVE ABLE STORM SASH

--SrI ; ,WOOD SASH

1

11

_./

,ROT0 OPERATOR

?LA

WOOD SASH SUB- SILL

*F'

REMOVABLE STORM SASH (INSIDE MOUNTING1 VENT HOLE BAR OPERATOR

-

ALTERNATIVES FIGURE 8

WEATHERSTRIP 7 LOCK-,

n

FRAME EXTENDED FACE MOULDING

?t_

AOJUSTER- REMOVABLE

~ ' m ' -

r R O T 0 OPERATOR STORM SASH OU TSIUE lNSlK

-

SILL

-

LOCK VENT HOLES EATHERSTRIP I I STEEL FRAME ALTERNATIVES FIGURE 9

SEATING FACE SASH OUTSIDE (a) WINDOW N - l CAULKING J (b) WINDOW N - 2

FIGURE 10

TYPICAL CROSS-SECTIONS OF ALUMINUM CASEMENT WINDOWS

_a#.

INSIDE v OUTSIDE JAMB SECTION HEAD OUTSIDE INSIDE

/f+g-

ROTO-OPERATOR / SILL

-

, FIGURE II

DETAILS OF STEEL CASEMENT WINDOW P - l &la. 77/9- a

OU TS/D€ STEEL SASH /' STEEL FRAME ALUMINUM SCREEN /NS/D€ JAMB S E C T I O N FIGURE 12

DETAIL OF S T E E L CASEMENT WINDOW P - 2

SEAL BETWEEN WINDOW FRAME AND MOUNTING PANEL

FIGURE 13

Prime Unit Locked Storm Unit (if any) Open

6

CGSB A i r Leakage Limit for Residential Windows - -

-

-

-

-

I I I I I I I h w ' I N . W . G. F I G U R E 14 D O U B L E - H U N G A N D V E R T I C A L S L I D I N G W I N D O W S P R I M E U N I T A I R L E A K A G E C H A R A C T E R 1 S T I C S an. 111y- 14

9

CGSB Air Leakage Limit for Residential Windows Prime Unit locked

0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0

h w ' I N . W . G .

F I G L I R E 15

P R O J E C T E D A N D C A S E M E N T W I N D O W P R I M E U N I T A I R L E A K A G E C H A R A C T E R 1 S T I C S .R. 1119- 1s

e -.

-. _{ASHRAE Design Values for} Wood Sliding Windows

* NON W/S 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 h W ' I N . W . G . F I G U R E 1 6 D E S l G N A I R L E A K A G E C H A R A C T E R 1 S T l C S O F D O U B L E - H U N G A N D V E R T I C A L S L l D I N G W I N D O W S A N D W O O D C A S E M E N T & P R O J E C T E D W I N D O W S m. 27ty-tb

I I I I I I I I

-

_.--*

_{ASHRAE Design Values for}

-

Steel Residential Casement * NON W/S - d - - -

-

-

-

- -

-

N-2

'

-

I

I I I

I

I 0 0.1 0.2 0. 3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 h w ' I N . W. G. F I G U R E 17 D E S I G N A I R L E A K A G E C H A R A C T E R I S T I C S O F M E T A L P R O J E C T E D & C A S E M E N T W I N D O W S 6 1 . 2 7 / 9 - 1 7

11E;Tb~KMINA'TION OF' WLNIIOW AIR LEAKAGE RATE

The following values were obtained during the window a i r leakage t e s t s : B a = b a r o m e t r i c p r e s s u r e a t r o o m t e m p e r a t u r e , in. m e r c u r y column Qa = r o o m r e l a t i v e humidity, p e r cent t a = r o o m t e m p e r a t u r e , O F t 1 = high p r e s s u r e box a i r t e m p e r a t u r e , O F 2

-

m e t e r i n g box a i r t e m p e r a t u r e , O F

Apw = window p r e s s u r e d i f f e r e n c e , m m w a t e r column

ho = o r i f i c e p r e s s u r e d i f f e r e n c e , m m w a t e r column.

The specific weights of a i r flowing through the window and through the o r i f i c e a r e found a s follows:

-

Wo - 320

TB,

- 0. 378pv

]

pcf T o

where,

Tw = absolute t e m p e r a t u r e , window air

OR

T o = absolute t e m p e r a t u r e , o r i f i c e m e t e r a i r

OR

Pv = a i r w a t e r vapour p r e s s u r e , in. m e r c u r y column

B c = t e m p e r a t u r e c o r r e c t e d b a r o m e t r i c p r e s s u r e , in. m e r c u r y column

0. 378

-

1 - R ( a i r ) R ( w a t e r v a p o u r ) R = g a s c o n s t a n t . T h e m e t e r e d flow i s , -

r .

188

cd

. d

& F , c u f t / m i n Q m - w h e r e , Cd = o r i f i c e flow coefficient, do = o r i f i c e d i a m e t e r , i n .

T h e m e t e r i n g box e x t r a n e o u s l e a k a g e , QL, which had been obtained by c a l i b r a t i o n , i s added t o t h e m e t e r e d flow; t h e a c t u a l flow t h r o u g h t h e window i s

T h e window flow i s c o n v e r t e d t o flow a t s t a n d a r d c o n d i t i o n s a t 7 0 ° F , 14. 70 p s i a and 0 p e r c e n t R H a s follows:

w h e r e ,

W

s = s p e c i f i c weight of a i r , s t a n d a r d conditions, = 0 . 0 7 5 lb/cu f t .

T h e above c o n v e r s i o n is c o r r e c t only when f u l l y t u r b u l e n t flow t h r o u g h t h e window i s a s s u m e d . B e c a u s e a l l but e x t r e m e l y tight windows will p r o b a b l y e x p e r i e n c e n e a r l y f u l l y t u r b u l e n t flows a t t h e

c o n d i t i o n s of t e s t ( i . e . , a t a window p r e s s u r e d i f f e r e n c e g r e a t e r t h a n 0 . 2 i n . w a t e r c o l u m n ) , t h e c o v e r s i o n is a good a p p r o x i m a t i o n . Qws T h e window a i r l e a k a g e r a t e =

,

cfm/ft whe r e , L C = length of p r i m e unit c r a c k , f t T h e s t a g n a t i o n p r e s s u r e e q u i v a l e n t of a wind of V m i l e s p e r h o u r f o r s t a n d a r d condition a i r i s given by hw = 4 . 8 2 x v 2 , i n . w a t e r c o l u m n .

The stagnation p r e s s u r e s equivalent t o v a r i o u s wind s p e e d s a r e given b e l o w . hw, i n . w g 0 . 0 1 2

V,

mph 5