NATIONAL BUREAU OF STANDARDS REPORT

NBS PROJECT NBS REPORT

1003-30-4707 July 16 , 1953 2665

Progre 3 s Report

WATER VAT OR TRANSMISSION I?'' REFRIGERATED WAREHOUSES

April 1 to June 30, 1953

by

F. J. Fowlit cl;, Jr.

B* 1. Robinsoil

Heating and Air Conditioning Section

Bui ding Technology Division

for

Office of fbe Quarternaat@r General

<NBS>

U. S. DEPARTMENT Of COMMERCE

NATIONAL BUREAU OF STANDARDS

The publication, rep

unless permission is

i

25.D.C, Such pern

cal ly prepared If th

Approved for public release by the

Director of the National Institute of

Standards and Technology (NIST)

on October 9, 2015.

n part, Is prohibited

mdards, Washington

lort has been speclflport for Its own use.

r rogrem Erport

WATER VATOR TRAhbKSalni. IK V matSUTEb . .Jh/j. ,

April 1 to June 30, 1953

*i&m alterations' of parts of the 4x0 ft. pat:* el apparatus were made, as a result of analysis of eperaU' nai tests conducted during the last quarter* The desiccant

box refrigerating equipment was changed to mah© its sontrol Independent of the cold box system* the water vap-or

generating capacity on the warm aid© was increased, and

an eiEtra blower ins tall©*- on the told side to incr- -auc- the

abserbins capacity of fcl a desiccant gystea.

Three rmm of several days* duration were sia-se to

determine the calibration coefficient of the differential

then^ocouple system which Indicates heat exchange between

tre warm side box and the laboratory root, ith t is ea~

eft latent, and the values of the differential then .acouple

reading and the measured heat input to the w&r tic-, it

1 3 possible to compute the heat flow through a tom; p&nel

durirpT a regular test, and thus to observe chan . a in its

insulating valu® if they occur.

an aluminum-faced panel with 3^5/S inches of flasn fiber

ion,

t,ure® equal to, 20 degrees F above, and 20 degrees > below,
„ 0H- • . - • .•*•'.-• . -V-r. • -A - „ - •.. ..M.*.-.- ••*•’> -• - • ***",—».*> -*>**- **« .. er i -i r*

*,.3 (in *

•

- > :• t -‘i-. :; - ^

•. 1 . •: -

•

2' ' ~~i : : C • C;

* - 3 ? • >'-&8iS>3 ‘ • vj'to ff 3

- .v* ir.

c.;i *3 ; ? s*l : . . , v .•?., v,: ;

r »£#<**•*.*? %z% :;> • U $ v'li h

, i .

-

.

- -

. ;

•

'

' V J ,!

-

• , r .

•

‘

' .

• I ,,'Xi V «?$' .

•

- : rir-

, no* • -? :*'

•: ; $ f -j imp* 49imi
- 2 *

room temperature. The cold side wan held at about

•23°F.

By simultaneous solution of pairs of the throe

equations representing the three test conditions, values

were derived for the cal3 bration coefficient of the warm

side differential thermocouples* ?*he three miner, thu*

obtained for the calibration coefficient were within 2

of the average value of 7# 3? watts of heat exchan — with

the room per millivolt of etsf of the differential th erasecouple* fh# C-value ©i" the test panel derived fross those

tests was about 30 percent higher than the value estimated

mi the basis of it® construction and material o ; t: is is in

part at least due to heat leakage around the panel through

the sealing eo»i ound ant laterally along the boy wall; .

An effort is being made to evaluate this heat leakage , although it should hoc he important se far as observation

of changes in test panel insulating value is concerned.

In the course ef these tests., observations on the

cold side of air temperatures and evaporator coil taiuperafcurea indicated that with the flooded evaporator and the

present air flow through the coil, their tamper stur* difference did not exceed 5*3 degrees F , for a coil temperature

of -2&*F» even with a small amount of buckle head introduced for temperature control. This is satisfactory for
4

• v « ,

•

* : 4 " 4; 44 Il4 t» 4 *.-..

5 r-v-,v :r ?• • ; .

"

- -• 4 -

’ "

' 4? V. I • V; > 4 44

‘ ' ' :• 7- :.r< ' 44 . * ??.$$

4 -

' AS-f h-fin />.. . ^ : i 4.,

44;?? ' 4 ‘t4 "4 ;

^ l.„ v*:4 i J-r,* 444 4 Siiil

44 4

'‘ 44 : ]>• : '• '3-

. 4 • .. 4 i: 4 >| •*.. ' * >H

1

. HU 4, ' , -4 .* g

4 4 4i- : : ‘

: ' ''‘4A?44:CA %»?.?./ "t -4m44; -H# •*.£

• .

• ••> "• -4 rv: ; •: ?* -

t .

• ' 'v ? 4 r.4 -nm*i

'• 4' > 4 -4;; "A • ri &.<« :44

4 • 7 | 44 : 4 f& *

:

'

. .

•
- 3 - preventing moisture accumulations m the coil f--r col

d

side relative huwidifcies up to 72 percent,

jla operational test of seven days' duration was

-,r

. t;h i. p\ t-' |;J- V. ' c; isade to observe and study the performance of the vapor

generating equipro»t and controls on the »«un* side? uad

of the vapor absorbing desiccant aysi and control & on

h the ©old side, The test panel used for this rw^ose had

an Blumin&m sheet on its w&rm side, with ere inch of

fiberrlas duet insulation glued to its cold side and exposed to the mid side air. The frasMi of the panel was

composed ©f 2x4 studs on 16-inch centers and 2x4 edges,

and was exposed fc# the cold box air. six 1/4- inch hole

a

were drilled in the aluisiam sheet in each of two tori mortal

lines 6 ft. apart vertically , the ins lation feeing

chaffered around the boles. Convective elreul&ti- n air

between the wars and cold sides through the so holes c: rrled

vapor froE the- warm side to the cold aid# at a steady rate

depending oil that tfeiwature -sod hmsldity aonditim s. Conclusions drawn from the teat were :

(a) The cantilever weiphin- devices for detertialng vapor

release and receipt rates on the two sides of the panel

performed satisfactorily, as did to e control nysb«n s

for both $.io-«s*
- c

; J : <

•; ." ;*r, ; ri.

* -

1 lai !•., ••’

.

% . . 43

. :•> 7 $ \:;r '

. .. -t ».. : 7 :

« :

'

.

•••

.

: 7.7 ; :

.

!

: 3 ' • - -7 '

;

" b'X firs". v . KY

* S?.$& I' v
— h, **

{b) Vapor flow from the warm side throv 'h the } olet- cf

the panel %*a» measured as equivalent to 3.3 ;ir**2r.s

ver hour per square foot of pan# 1. This is in '•• r^eassent with the vapor flow that woo!4 be predicted on

t,h% basis of a coefficient of di«cbarge lor t # holes

, , for i

of arid 5-U l.H. on the war- side sm 30".;"

moo bb$ h * B • on the cold aide-*

s,

trol®i operated vary satisfactorily for the entire

test period*

{$) f!:: $ rate of vapor rseeir t on the cola lid# was ?m.- .ia!i.y

twice the rate of vapor rale*** on the warm mi -mm, art

tended to approach the latter m ttom test was continue .

Calculation shows that the excess was probably cue to

moisture released fro* the eapoaed wood frerla* of the

test paMol *

••be last conclusion indicates the ianertame® m avoiding hygroscopic materials exposed to the air inside the

apparatus. It «*&*•«*« alee the important role vdsyad by

hygroscopic materials, such as wood members, t* the vapor

transmiesiom or accumulation characteristics of refri rr ,tod

insulated at r -ictures .
*

• ' TOl .

.

Al-4

, ! 3

.

*

r.

. i

'I '(. 4

' -

.

:

, j J

i •; :•
Yhs coefficient or dlschsr .

. «? of Ov/'"- vounr or

ti c l/k~lmh. hole© is not unreasonable for boles of

this sis® mad® by a hand drill 1b soft atotnun sheet

l/U inch thick . It is b«l loved tKit rwwouable reliance can be pla«*4 on the method of calculator- such

ventilation rates, Which wiU be useful -ban pant is re

to be design@d to investigate the value ot cold - ilv

ventilation in test® to be ri&4® later in the proved

pro nrtv*

It is believed, 'roc the experience of trejs tret.-.;,

tiat tie next phase of the presra*

the deter»inati»»< of

the performance of full-niee panel* of various deal • —

can be initiated at once. Material baa. been ob,v me., '.or

the first such panel to be tested, «' lc >‘ W^ J ''

r-.f koaoseneous nen-by rosce - ic naterial ( tyrofoaf , of

iow -. vtanee and sodwhtely lo * «

The material was furnished without charge by the <-ovChemical ;f: orporstion

.

jfjyr ^...itefeiyn Kite the yy

attarberwaater Corps, it was decided to construct an arparatu. for eeaeurtns the vapor permeance of sables, about
. -;t v, t 'T'i/ ..£ -

^ ’&A'l $&%£#**&& -twf Si S c '*A>?'f

i w -

' • i Ml

,

* rfT.?e ? X- ••'• i-‘ 'H *M ffco- -: i*.:- sk? f i«$ <K^*iX

; i-; y ; s £);*£ -Tt&f&i ?< r,&3«> C?2

v

• s •

! ' : ~.i ’•* -;

**#1 0 f

'

, x ?. r:;

'

. .

: -

- \

- -

’

' W fi •

Mi ", I* • > i

•”•

' * * - ' :;:

i

.

•

• ••>. ?

- 1>* :

’

: '»% ;•

» &> 4 #*! ' • ' f. u 1 1» » tiJS* *£>

' ';• i ,

- : .

;

.*• ?

: u:.'- •*•• ^

y

• : . -a

:" •

• t!

:. &

' '

• . .. - ' <*'l
- 6 *

one foot square, of the materials used in the coi vtructiori of the Ax# ft. test panels, or its actual s r ct res*

An apparatus was devised, util i*l»c a hypoder* ic syringe,

5n which the feed of water necessary to maintai:- a sf ady

vapor flow through a specimen is automat ically imtrod- cod,

metered and controlled, with relatively simple equipment.

A working model of the moisture feed!nr and xsetorim: cotpoaeafc has bees* Made and tested* Mar© arc bto- - oor ; :oo

out to build a complete permeance apparatus caoab: of

o- oration at different temperaPure 3 and humiditioo -t. v.he

two sides of the $p$&SM*nm caturea of the apparatus art

that the results will ’ ave been obtain®'.-' a® soon a >.&

specimen itself has come to an equilibrium vith U;“

posed eorditiona, and that little or no attand&nce c -

s measurement should be necessary.

Ton photographs are attached showing views of toe axe

ft. panel apparatus and parts, as follows?

Figure X. Oenersu. view with apparatus in horisontsu. : ‘ siti- -

Figure a* * " « " * vertical

Flrure 3. Apparatus separated*

1 1 ure 4. Closeup of war-; side*

Figure 5. " * cold side.
i( .

- *' ' f r r^:vT5 r

; . " '

• , «*

: i’:

' '

. *

: •

'

. /;>. i

‘

. ,

* 3t % l? t W* ' * *

, S - 'X'J It

vtr it

, »4 '•w V 1
mM

1 -

Pi «r«f 6. Cldseiip o-' desiccant box,

FI.furs ?. &ef!rif«r*iieR equi **.- &nt and eon t rein*

Figure ## IMfcrcamfe p«me&*

Pi.-ur© 9. arm side of test, :>aii©i showing 1/4 inchholes end thermocouple stamens ( black retches)

Figure 10* Cold side yi test r>ar-el *
'

*•

h- ; - : ' ' * .
FIG

<MO

H

fc











FIG, g

FIG. 9
o
FIG. 10