Development of laboratory heat transfer apparatus
by Robert A Johnson
A THESIS Submitted to the Graduate Faculty in partial fulfillment of the requirements for the degree
of Master of Science in Mechanical Engineering
Montana State University
© Copyright by Robert A Johnson (1955)
Abstract:
Many arrangements are possible for developing a heating laboratory installation that will cover as
many heating problems as is practical with one primary installation. Montana State College needed an
installation of this type so that boiler and heat transfer tests could be made under more controllable
conditions than were previously available. In addition, investigation was needed on the, practicability
of radiant heating in this area where extremes of climactic conditions are present.
The material presented in this thesis attempts to present the solution for the above problem, a
description of materials used, and test results noted.
Results obtained from the series of tests conducted show that further refinements are necessary in the
method of controlling radiant hot water floor panels before this method of heating will be entirely
satisfactory in this climate. Sun load is one of the main obstacles to overcome in developing a suitable
control system for panel heating.
Chapter V presents another method of obtaining warm floors with the advantage of winter air
conditioning in the form of the split system of warm air panel heating. This system tends to overcome
the inherent lag noted with hot water panel systems, and is suitable for use with controls presently
available. DEVELOPMENT OP LABORATORY
HEAT TRANSFER APPARATUS
ty
ROBERT A, JOHNSON
A THESIS'
S ubm itted t o th e g ra d u a te F a c u lty
in
p a r t i a l f u l f i l l m e n t o f th e re q u irem en ts
f o r th e d eg ree o f
M aster o f Science' i n M echanical E n g in e e rin g
at
Montana S ta te C ollege
Approved«
Head,. Major D epartm ent
C hairm an, Examining Committee
Bozeman,. ,Mpntana
Ju n ei, 1955
J
d.
TABLE OP CONTENTS
A b s tr a c t...........................................................................................
C hapter I , 0In in g Components
I n tr o d u c tio n ............................................................................................................................. g
B o ile r d e s c r i p t i o n ......................................................... ............ ...........................................g
H eat E xchanger.......................................................................................................................... g
Floir M eter...................... .............. ......................... ................................................... .............. 7
S a fe ty D e v ic e s..............................................................................................................................
P re ssu re R e l ie f V a l v e .................... ........................................................
7
R educing V a lv e ................................................................................. ..................................
Flow Cheek V a lv e ............................................................................ ........................................ 3
A ir Tank and F i t t i n g s .......................................................................................................... ....
B e ll and G o sse tt A i r t r o l ....................................................................................................
O p e ratin g I n s t r u c t i o n f o r A i r t r o l ...................................................................................
W ater M ete r.............................*...................................................................................................
Gas M eter..................................................................................................................................... ..
C olor Coding o f P in e s .......................................................................................................... ..
P in in g D ia g ra m ..........................................................................................................................
C hanter I I , E l e c t r i c a l Comnonents
I n tr o d u c ti o n ..................................... ........................................................................................ ..
High L im it C o n tro l..............................
18
Low L im it C o n tro l ................................................................................................................. ..
Penn T h e rm o sta t............... .......................................................................................................24
M inneapolis Honeywell E le c tr o n ic M o d u f lo w ................................................. . . . . . 2 5
I n s t a l l a t i o n and C a l ib r a tio n ................................................................................ 25
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ABSTRACT
Many arrangem ents a re p o s s ib le f o r d e v elo p in g a h e a tin g la b o ra to ry in®
s t a l l a t i o n t h a t w i l l cover as many h e a tin g problems as i s p r a c t i c a l w ith
one p rim a ry i n s t a l l a t i o n . Montana S ta te C o lleg e needed a n i n s t a l l a t i o n o f
t h i s ty p e so t h a t b o i l e r and h e a t t r a n s f e r t e s t s co u ld be made under more
c o n tr o lla b le c o n d itio n s th a n w ere p r e v io u s ly a v a il a b le . In a d d itio n * in®
v e s t i g a t i o n was needed o n 't h e . p r a c t i c a b i l i t y o f r a d ia n t h e a tin g in t h i s
a r e a w here extrem es o f c l i m # i c c c o n d itio n s a re p r e s e n t.
The material presented in th is th e sis attempts to present the sola®
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t i o n f o r th e .above problem * a d e s c r ip ti o n o f m a te r ia ls u s e d , and t e s t r e ­
s u l t s n o te d .
R e s u lts o b ta in e d from th e s e r ie s o f t e s t s conducted show t h a t f u r th e r
re fin e m e n ts a re n e c e s s a ry i n th e method o f c o n t r o llin g r a d ia n t h o t w a te r
f l o o r p a n e ls b e fo re t h i s method o f " h ea tin g w i l l be e n t i r e l y s a t i s f a c t o r y
i n t h i s c lim a te . Sun lo a d i s one o f th e m ain o b s ta c le s t o overcome 'in tie®
v e I oping a s u i t a b l e c o n tr o l system f o r p a n e l h e a tin g .
C hapter V p r e s e n ts a n o th e r method o f o b ta in in g warm f lo o r s w ith th e
advantage o f w in te r a i r . c o n d itio n in g i n t h e form o f th e s p l i t system o f
warm a i r p a n e l h e a tin g . This sy stem te n d s t o overcome th e in h e re n t la g
n o te d w ith h o t w a te r p an el system s* and i s s u ita b le f o r use w ith c o n tro ls
p r e s e n tly a v a i l a b l e .
x
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C hapter I
' '’
PIPING COMPONENTS
’
'
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In tro d u c tio n .
C h ap ter I c o n s is ts o f th e fo llo w in g t o p i c s s ■
P a s o r i p t i on o f t o i l e r and operation®
'D e s c r ip tio n o f s a f e t y GivicOs used*
"IiS^asuring d e v ice s ' i n w a te r l i n e s »
C olor c o d in g s »
1
Com posite' p ip in g -d ia g ra m .
T his 'c h a p te r c o n ta in s a d e p p rip tio n -o f a l l components used i n th e pip«=
in g s y s te m ^ ,to g e th e r w ith m easuring d e v ic e s t h a t are d i r e c t l y co n n ected t o
th e w a te r li n e s and g a s 'l i n e s i
I l l u s t r a t i o n s show ing•p ip in g arrangem ents
can be used in . c o n ju n c tio n ' w ith th e p ip in g -1diagram /,in o rd e r t o p ic tu r e th e
o v e r a ll piping'- Component in s ta lla tio n ®
D e s c rip tio n s a re b ased on m a te ria l
s u p p lie d by m a n u fa ctu rers p lu s v is u a l ex am in atio n o f eq u ip m en t0
, ;
. . .
BOILER DESCRIPTION AND OPERATION
Sn American S ta n d a rd e n p ire ty p e S=GA-E .gas b u rn in g b o i l e r is used i n
t h i s 'system®
B tu p e r hour®
I t i s , a .f i v e s e c tio n b o i l e r w ith an in p u t r a t i n g of 105,000
The b o i l e r i s equipped w ith a u to m atic f i l l i n g and r e l i e f
v a lv e s p lu s s a f e ty d e v ic e s i n th e gas lin e so t h a t i t may be l e f t unat=
te n d e d f o r lo n g p e rio d s o f tim e w ith o u t damage r e s u l t i n g due. to gas f a i l ­
u re o r e x c e s s iv e , p re s s u re i n 't h e system® . These s a f e t y d e v ice s, w i l l be d is =
c u sse d t o a g r e a te r ' e x te n t l a t e r i n th e ,c h a p te r®
HEAT EXCHANGER
The h e a t exchanger i n t h i s system i s used f o r lo a d in g th e b o i l e r a t
7
r a t e d c a p a c ity r e g a r d le s s o f th e tim e o f y e a r or w e a t h e r I t i s u s e fu l
when ru n n in g b o i l e r t e s t s and i s a ls o a v a ila b le f o r ru n n in g h e a t t r a n s ”
fe r te s ts .
Gold w a te r f o r c o d lin g i s c i r c u l a t e d th ro u g h th e tu b es w h ile
h o t w a te r from th e b o i l e r i s p a sse d around th e tu b e s .
The exchanger i s
a 10 p a ss type..
FLOW METER
This p ie c e o f equipm ent i s lo c a te d bn th e w a ll b e sid e th e r e tu r n le g
from f l o o r c o il's t o b o i l e r and i s shown i n f ig u r e s I and 2 .
I t is a s ta n d ­
a rd s h a rp edged o r i f i c e i n s t a l l a t i o n co u p led t o a re c o rd in g manometer6
The s iz e o f th e O r if ic e used was' .8 7 7 ” w hich gave a s a t i s f a c t o r y d i f f e r ­
e n t i a l on b o i l e r and exchanger t e s t s e
A l a r g e r o r i f i c e w ould be used i f
d e te rm in in g flo w th ro u g h th e f lo o r panel.SiFEIT DEVICES .
I n any system o f t h i s ty p e s v a rio u s s a f e t y d ev ice s a re n e c e s sa ry i n
o rd e r t o p r o t e c t b o th o p e ra to rs and th e sy stem i t s e l f from any damage t h a t
m ight r e s u lto
An a u to m a tic f i l l e r r e l i e f v a lv e i s lo c a te d on th e i n l e t t o th e b O ile r0
This v a lv e s e r v e s a d u a l p u rp o se , t h a t o f a u to m a tic a lly p ro v id in g any make-­
up w a te r n e c e s s a ry t o keep th e b o i l e r o p e ra tin g a t a p r e s s u r e range o f fro m
10 t o 30 pounds p e r sq u a re in c h .
I f p re s s u re drops below 10 pounds, th e
c i t y w a te r' p re s s u re ' i s a b le t o .push open a s p r in g o p e ra te d v a lf e and add
w a te r u n t i l th e d i f f e r e n t i a l d e c re a se s t o th e p o in t where th e s p rin g has
s u f f i c i e n t s te n g th t o h o ld th e v alv e c lo se d .- ' In case o f e x c e s s iv e p re s s u re
i n th e sy stem (over 30 p o u n d s), a n o th e r s p r in g loaded v a lv e i n th e same
c a s in g as th e f i l l e r v a lv e opens and r e l i e v e s th e system i n t o th e sump ta n k
8
u n t i l s a f e o p e ra tin g p re s s u re i s a g a in a c h ie v e d » This v a lv e can be seen
i n f ig u r e I next, t o th e b o i l e r and lo cated , on th e w a te r l i n e t h a t goes in®.'
t o th e s id e o f th e b o ile r , under th e g a g es0
In a sy stem o f t h i s 't y p e th e r e i s alw ays th e Chance o f f a i l u r e i n th e
v a rio u s s a f e t y d e v ice s u s e d .
I f th e h ig h l i m i t c o n tro l f a i l e d t o s h u t th e
b o i l e r down a t th e upper l i m i t tem perature, s u f f i c i e n t te m p e ra tu re m ight
be developed t o c o n v e rt some o f th e w a te r t o stea m . - I n t h i s e v en t & safes-.
t y r e l i e f v a lv e s e t a t 30 pounds opening p re s s u re sh o u ld be p re s e n t t o re-.
Iie v e th e system o f e x c e s s iv e p r e s s u r e s ,
t h i s v alv e i s shown i n f ig u r e %
i n th e upper r i g h t hand c o rn e r n e x t t o th e h e a t exchanger., 'P ro v isio n m ust a ls o he made when u s in g n a tu r a l gas 0 t o ‘p r o te c t the. an-*
t i r e b u ild in g from e x p lo s iv e m ix tu res o d c u rin g when th e gas su p p ly i s s h u t
off. f o r a w h ile and then.com es pn again*
P r o te c tio n i n t h i s ca se" is -pro­
v id e d by a s ta n d a rd Baso v a lv e Which c lo s e s o f f th e gas su p p ly i n e v e n t o f
p i l o t flam® f a i l u r e and p re v e n ts ad m issio n o f gas t o th e b u rn e r u n t i l th e
p i l o t flam e i s r e = I g n lte d .
This v a lv e i s lo c a te d i n th e b o i l e r ho u sin g
and i s shown i n f ig u r e 6 and f ig u r e 8«''
,
.
.
.
FLOW GBBGK VhLVB
This i s a s p e c ia l ty p e o f check v a lv e which c lo s e s when th e circa™
l a t e r i s n o t i n o p e ra tio n and p re v e n ts th e rm a l c i r c u l a t i o n from ta k in g
p la c e when th e c i r c u l a t o r i s stopped.*
I f t h i s d ev ice i s n o t employed*' h o t •
w a te r w i l l te n d t o c irc u la te - th ro u g h th e sy stem when such c i r c u l a t i o n i s
n o t d e s ir e d or c a l l e d f o r by th e th e r m o s ta tic c o n t r o l s .
I t i s n e c e s sa ry
t h a t a flo w check be alw ays in c lu d e d i n any r a d ia n t system*.
The v alv e
used i n t h i s system i s lo c a te d on th e l i n e ru n n in g , t o th e p a n e l and is
9
F ig u re I
4
10
11
s i t u a t e d where th e lin e s goes over th e to p Of th e w a l l .
I t i s n o t shown i n
any o f th e i l l u s t r a t i o n s b u t i s made by th e Thrush M an u factu rin g Company
and h as a 1le v e r on th e s id e s o 't h a t th e v a lv e can be lo c k ed i n th e Open po­
s i t i o n when s d d e s ir e d .
I n d e s ig n i t i s s im ila r t o a s ta n d a rd cheek v alv e
w ith th e e x c e p tio n th a t, a h e a v ie r w e ig h t i s used on th e h in g e d v alv e s e a t
cover so t h a t i t w i l l 's t a y c lo s e d when c o n fro n te d w ith th e rm a l c i r c u l a t i o n
p re s s u re s ^ b u t W l l - -bpen'when'exppsWd^ to g r e a te r p re s s u re s as e x e r te d b y
th e ’ c i r c u l a t i n g purnp^o ■
■' :
• • • : ■ • MR TMK MD FITTIBGS
W ater h e a te d from 40 F t o 200 F expands ab o u t .04 o f th e o r ig i n a l v o l­
ume-. ' IhO e x p a n sio n ta n k p e rm its th e change' i n ' volume o f th e w ater i n th e
h e a tin g sy stem t o ta k e p la c e w ith o u t lo s s o f b o i l e r w a te r th ro u g h th e ree>
l i e f v a lv e .
The ta n k u sed i n t h i s sy stem i s o f th e c lo s e d ty p e , t h a t is #
i t i s s e a le d a g a in s t f r e e v e n tin g t o t h e atm o sp h ere.
L o c a tio n o f th e ta n k
i s o f l i t t l e im portance as i t may be lo c a te d a t any p o in t, i n th e system
r e g a r d le s s o f e le v a t i o n .
The minimum c o n te n ts o f a c lo s e d ta n k must be
such t h a t th e e x p an sio n o f th e w a te r due t o in c re a s e o f te m p e ratu re w i l l
be cu sh io n ed a g a in s t a r e s e r v o i r o f com pressed a i r above th e w ater le v e l i n
th e e x p a n sio n ta n k .
The ta n k m ust p ro v id e space n o t o n ly f o r th e 'c h a n g e i n
w a te r volume# b u t a ls o f o r v a r ia tio n s i n a i r volume w ith in th e ta n k due t o
changes i n a i r p r e s s u r e . ' The e x p a n sio n ta n k i s v i s i b l e i n f ig u r e 3«
A ir tr o l
" 1' 1 '
Means must be p ro v id ed t o a d ju s t th e p ro p o rtio n o f a i r w ith in any
c lo s e d e x p an sio n ta n k and t h i s i s p ro v id e d f o r by means o f th e a i r t r o l
fittin g s .
M r t r o l i s th e tr a d e name o f th e B e ll and G o s s e tt Co. d ev ice
12
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Table I
S ame A s B oiler
O utlet T apping
'I
IS
f o r m a in ta in in g p ro p e r a i r su p p ly w ith in th e ta n k .
I l l u s t r a t i o n s fig u r e 4
and ta b l e I show t y p i c a l a p p lic a tio n o f f i t t i n g s along w ith v a rio u s • s iz e s
a v a ila b le .
O p e ratin g I n s tr u c tio n s f o r A ir tr o l
I.
F i l l sy stem ; v e n t h ig h p o in ts and r a d i a t o r s .
S 0 Resume f i l l i n g u n t i l gauge re a d s S t o 5 pounds i n e x ce ss o f t h a t re=*
q u ire d t o f i l l th e h ig h e s t p o in t o f th e system o r t o a minimum o f 15
t o 17 F s i on a s in g le s to r y i n s t a l l a t i o n .)
5.
Open a i r v e n t a t b o tto m o f a i r t r o l u n t i l w a te r flo w s f r e e l y w ith no
a i r , th e n c lo s e t i g h t .
Udte th e low ered gauge re a d in g a f t e r v e n tin g ,
T his v e n t v a lv e sh o u ld be u sed o n ly when p u ttin g th e sy stem i n t o o p e r­
a t i o n f o r th e f i r s t tim e or a f t e r d r a in in g th e sy ste m .
4,
R epeat o p e ra tio n I and 2»
5»
S t a r t f i r e b u t do n o t s t a r t (jsilroulator and b rin g b o i l e r up t o 220°
temp and s to p f i r i n g .
6.
W ait u n t i l th e r e i s ho sound o f a i r v e n tin g i n t o th e ta n k and th e n
s t a r t th e c i r c u l a t o r ,
7.
S to p ,pump when b o i l e r tem p, drops t o 120° and s t a r t f i r e a g a in u n t i l
tem p. a g M r re a c h e s ' 2 2 0 °,
8.
,
■' ■
R epeat s te p s ■6 ' and -7 , ................. ■'
9 o S e t c o n tr o l h a c k t o O p eratin g tem p eratu re; f o r th e jo b .'
ID .
I t may be n e c e s s a ry t o r e p e a t s te p 2 and S i n a week o r t e n d a y s.
'
■.
' .I
The a i r t r o l f i t t i n g t h a t c o n n ec ts t o th e h o lle r o p e ra te s on th e p r i n ­
c i p l e t h a t th e a i r b u b b les w i l l see k th e h i g h e s t p a r t o f a system .
'
■
' '
'
’
.
,
I
•
- I
■
Ott
■
ch an g in g d i r e c t i o n t o e n te r th e a i r t r o l tu b e on th e b o i l e r f i t t i n g , th e a i r
14
i s s e p a ra te d from th e w a te r and i s d ir e c te d up t o th e e x p sn sitin ta n k where
th e a i r t r o l ta n k f i t t i n g ’m a in ta in s th e p ro p e r r e l a t i o n s h i p betw een w a te r
and s i r . '
' '''
.....................
WATlSR MBTSR AM) G-AS SgTER
' 1
The w a te r m eter u sed i n t h i s i n s t a l l a t i o n i s a s ta n d a rd Jiershey w a te r
m a te r.
I t i s u s e f u l f o r m easuring th e volume o f p o o lin g w a te r re q u ire d f o r
th e h e a t e x c h a n g e r.
The m e te r i s lo c a te d on th e w a ll b e sid e th e h e a t ex«=
ch an g er and i s n o t shown i n any i l l u s t r a t i o n .
The gas m eter u sed i s a bello w s ty p e w ith d i a l s showing re a d in g s t o
if f t . p e r r e v o lu tio n .
P re ssu re o f th e gas i s gauged by means o f a w a ter
manometer lo c a te d i n th e gas l i n e betw een m eter and b o i l e r .
A therm om eter
w e ll i s a ls o lo c a te d i n th e same l in e t o re c o r d incom ing gas te m p e ra tu re ,
OOLOR GGDIlG OF P I S
'
;
I n o rd e r t o f a c i l i t a t e u n d e rs ta n d in g o f th e p ip in g la y o u t used i n th e
sy ste m , e ac h ' o f th e p ip e s i s c o lo r coded a c c o rd in g t o i t s u se i n th e sys«=
tern.. The fo llo w in g c o lo rs a re u s e d :
G reen—
--------— -c o ld w a te r lin e s
Black-—
Orange-*^—
— “— - —gas lin e s .
—
'—
hot w a te r l i n e s
R ed-'— •—- - - - - - 1—- e l e c t r i c a l c i r c u i t s and com ponents» a ls o f o r
s a f e ty d e v ic e s
Ye I law --"-= ——" - “ " a l l v a lv e s a re y ello w
Gray—— 'r—'*—— —r e t u r n l i n e s t o th e b o ile r
,.d ra in l i n e s
B lue and G reen------- com bination- d r a i n and c o ld w a te r ■
15
Blwa = -g rey ---- ------- -flo w m e te r, h e a t exchanger » pumps., w ater m eter
PIPING DIAGRAM
F ig u re 5 shows a l i n e diagram o f a l l p ip in g c i r c u i t s .
Arrows placed
th ro u g h o u t th e diagram show d i r e c t i o n o f flo w .
B o ile r t e s t :
fh e b o i l e r t e s t i s conducted u s in g th e fo llo w in g a p p a ra tu s shown on
th e p ip in g diagram : h e a t e x ch a n g e r, b o i l e r , c i r c u l a t i n g pump, and, flow
m e te r,
Talw es sh o u ld be a d ju s te d i n e i t h e r th e open or c lo s e d p o s itio n t o
pass a l l w a te r th ro u g h th e b o i l e r ,
W ater n e x t goes t o th e h e a t exchanger
w here i t lo s e s h e a t t o c o o lin g w a te r ,
passes, th ro u g h th e flow m e te r,
From, th e h e a t ex changer a l l w a te r '
th e w a te r n e x t r e tu r n s t o th e b o ile r
th ro u g h th e c i r c u l a t i n g puthp.
C ooling w a te r i s p a ss e d th ro u g h th e h e a t exchanger tu b e s and from
t h e r e ' i t i s s e n t t o a f l o o r d r a in i n th e foundry® •
IeB iperatures f o r th e b o ile r t e s t a re ta k e n a t i n l e t and o u tle t o f th e
;
"
'
•
- I.:
'
I.'
b o ile r,
Tem perature o f incom ing gag i s a ls o re c o rd e d .
Note':
E x p la n a tio n s ' p re s e n te d h e re c o n ce rn p ip in g o n ly and do no t
e x p la in n e c e s s a ry a d ju stm e n ts t o th e e l e c t r i c a l c i r c u i t s «
H eat Exchanger t e s t :
The same v a lv e p o s itio n in g and a p p a ra tu s i s used f o r t h i s t e s t as f o r
th e b o i l e r t e s t .
Tem peratures a re ta k e n a t i n l e t and o u t l e t o f th e h e a t
exchanger f o r b o th h o t b o i l e r w a ter and c o o lin g w a te r .
W eight o f c o o lin g
w a te r c i r c u l a t e d I s m easured U sing th e w a te r m e te r' o f th e sy stem .
Hot
w a te r flow i s m easured b y means o f .th e flo w m e te r.
F lo o r p a n e l t e s t s , a ls o room h e a tin g ;
V alves sh o u ld be a d ju s te d so t h a t a l l flow from th e c i r c u l a t i n g pump
16
TO C L
TO
LAB
COIL
A IR
VALVGS
FROM C O l L
TO
DRAIN
EXP
TANK
BOILER
M ODUFLOkV
CIRC.
ORa i n
PIPING
p u m p
DIAGRAM
Figure 5
p a sse s th ro u g h th e f l o o r c o i l .
V alve number 1 0 , f ig u r e 5 , should be a d ­
ju s te d so t h a t most flo w from th e pump b y -p a sses th e b o i l e r »
I t is not
n e c e s sa ry , t o measure flow when t e s t i n g rooni c o n tr o ls , b u t i f flow measure®
n®nt i s r e q u ir e d , w a te r r e tu r n in g from th e f lo o r p an el may be re tu rn e d to
th e b o i l e r o f th e flow meter-o
Hot w a te r su p p ly :
The h e a tin g u n i t may a ls o be u t i l i z e d t o p ro v id e h o t w a te r t o th e
C iv il E ng in eerin g , ’V e t” room i n e v e n t o f f a i l u r e o f o th e r so u rc es o f h o t
w a te r s u p p ly .
I h i s means o f su p p ly in g h o t w a te r i s o n ly u s e f u l i n emer­
g en cies * as th e f i l l e r r e l i e f waive i s th e o n ly source o f makeup w a ter f o r
th is b o ile r I n s ta lla tio n 0
18
G hapter I l
ELECTBIGiL COMPONENTS
Introdw tion s•
C hapter I I c o n s is ts o f th e fo llo w in g t o p ic s ;
D e s c rip tio n o f High L im it C o n tro l
D e s c r ip tio n o f Low L im it C o n tro l
Penn T herm ostat
M inneapolis Honeywell E le c tr o n ic Moduflov/ sy stem
Composite E l e c t r i c a l Diagram
^ h is c h a p te r d e s c rib e s th e c o n tr o ls a tta c h e d t o th e e l e c t r i c a l system
t h a t g u a ra n tee s a f e t y o f o p e r a tio n .
The d e s c r ip tio n o f th e two ty p e s o f
c o n tr o l system i n use on t h i s i n s t a l l a t i o n a re d e sc rib e d i n as much d e t a i l
as i s a v a ila b le th ro u g h v i s u a l in s p e c tio n and m a n u fa c tu re r’ s d e s c rip tio n ?
i’he Penn room th e rm o s ta t and Moduflow .w ere chosen f o r use i n t h i s s y s ­
tem b ecause th e y p re s e n t th e extrem e l i m i t s Of p re s e n t h e a t c o n tro ls ?
One
i s v e ry sim ple w h ile th e o th e r i s c o n s id e ra b ly more c o m p lic a te d and expen=
s iv e .
I n a n o th e r c h a p te r r e s u l t s o f t e s t s made'?on th e s e tw o system s w i l l
' 'V
be shown and com parisons made,
HIGH LIMIT COHPBGL
(
This b o i l e r system i s a rra n g ed ' so t h a t w a te r te m p e ra tu re i n th e b o i l e r i s
m a in ta in ed c o n s ta n tly betw een a, h ig h e r and a low er l i m i t .
A ll room tem per=
a tu r e c o n tr o ls o p e ra te th e c i r c u l a t i n g pump only# s t a r t i n g th e pump on a
demand f o r h e a t and s to p p in g i t when re q u ire m e n ts are s a t i s f i e d .
I n a sy stem o f t h i s ty p e an e s s e n t i a l c o n tr o l i s n e c e s s a r ily a h ig h
l i m i t c o n tr o l t o p re v e n t b o i l e r .tem p eratu res, from e x ce e d in g th e s a fe l i m i t .
<
19
1. M anual S h u t-O ff Valve
2 . P ilot Cock
3 . Baso A u to m a tic P ilo t Valve
4. P ilo t B u rn e r
F igur# 6
F lg w e 7
20
Figure 9
/
21
The c o n tro l used i s a " D e tr o it" V-574-FW e l e c t r i c gas v a lv e .
t r o l is shown i n F ig u re 7 and F ig u re 8 .
This con­
In F ig u re 8 th e h ig h l im it c a r t
o f th e c o n tr o l i s shown on th e extrem e l e f t s id e of th e c o n tr o l w ith a
k n u rle d a d ju s tin g hand w heel b e in g used t o s e t te n s io n i n th e s o rin g in
o rd e r t o v a ry th e upper b o i l e r w ater l i m i t te m o e ra tu re .
^ h is gas valve i s a d i r e c t o n erated sn ao - a c tin g v a lv e .
The o p e ra t­
in g oower i s o b ta in e d from a s tro n g b im e ta l s t r i p motor which opens th e
main v alv e when h e ate d by a low v o lta g e h e a te r e le m e n t.
Low v o lta g e i s
s u o o lie d by th e tra n s fo rm e r shown a t th eto o o f F igure 1 0 .
When th e low l i m i t c o n ta c ts c l o s e , a low v o lta g e c u r r e n t su o o lie d by
th e tra n s fo rm e r p a sse s from th e te rm in a ls th ro u g h th e h e a te r e le m e n t.
The
h e a t from th e elem ent causes th e b im e ta l motor to warp uow ard, th u s a p p ly ­
in g a l i f t i n g fo rc e on th e valve ste m .
The valv e i s n o rm ally h eld c lo se d
by a s tr o n g , c y l i n d r i c a l , perm anent magnet w hich e x e r ts a downward o u ll on
th e c i r c u l a r arm ature which i s a tta c h e d t o th e v alv e stem .
When th e c lo s in g o u ll o f th e magnet i s overcome by th e b im e ta l m o to r,
th e v alv e opens w ith a p o s itiv e snap a o t i o n - - f i r s t t o a minimum flow e s ta b ­
lis h e d by th e s te p opening mechanism and th e n , a f t e r a d e la y o f 8 to 10 seo ,
w i l l c o n tin u e t o i t s maximum o p en in g .
When th e h ig h e r l i m i t te m o e ra tu re i s re a c h e d , th e e n t i r e b im etal a s ­
sembly i s moved, m e c h a n ic a lly , down in to th e m agnetic f i e l d and th e v alv e
snaps c lo s e d .
LOT LIMIT CONTROL
This c o n tr o l i s in s e r te d d i r e c t l y i n t o th e to o o f th e b o i l e r .
I t is
a "T hrush w a te r temo c o n tro l" and c o n s is ts m erely o f a s e t o f o o n ta o ts
22
Figure 10
23
/
F ig u r e 11
wi&eii a re 'til'd'sed w^en b o i l e r w a te r
i s -ieiiuoed t o a d eterm in ed ' le v e l',
th e re b y a e s tiv a tin g th e h ea tin g elem ent o f " th e D e tr o it v a lv e and e a u sih g th e
• b u rn e r t o 1home Oti0
Ho p i c t o r i a l i l l u s t r a t i o n o f t h i s 'sw itc h 'is shdvm o th e r
th a n bn th e 1Composite e l e c t r i c a l c i r c u i t diagram= '
'
...........fTHSEMOSTlT' ' '
'
,
. The'rdom ' th e rm o s ta t used on t h i s sy stem i s ' a ' Eenn two -w ire : he a t '' an­
t i c i p a t i n g 'l i n e v o lta g e th e r m o s ta t. "H eat a n t i c i p a t i o n " i s p ro v id ed b y 'a
t a i l o r e d " h e a te r" made out o f niohrom s w ire and p r o te c te d b y a molded p la s ^
t i c bbvero
I t i s shown' ih ' Pijghrd '1 1 * ' Because normal c u r r e n t flow through-
th e th e r m o s ta t'p a s s e s 'th r o u g h 'th e h e a t e r o i t I s n e c e s s a ry when i n s t a l l i n g
t o o b ta in th e p ro p e r h e a te r d e s ig n a tio n depending upon th e ampere r a t i n g
'
o f th e c i r c u l a t i n g m otor name, p la t© .' ' These h e a te rs c an be Changed r e a d i l y
by rem oving screw "0" and te rm in a ls ”1" and " I" as shown on F ig u re I l 9i .
liTem trol" i s a p a te n te d tr a d e name f o r Eenn room th e rm o s ta ts which
in c o r p o r a te '' t lie p r in c ip le ' o f h e a t a n tic ip a tio n ®
Penh Tem trol in c o rp o ra te s a s e n s i t i v e b im e ta l te m p e ra tu re elem ent
w hich a c tu a te s ' th e s n a p - a c tin g permanent'' magnet ty p e c o n ta c ts *
B im etal
a c tio n i s m o d ifie d , how ever, by a r t i f i c i a l h e a t w ith in th e in stru m e n t i t -
'
s e l f , i n s te p w ith in c r e a s in g or d e c re a s in g te m p e ra tu re s i n th e a i r su r=
ro u n d in g :th e in s tru m e n t. ' "H eat a n tic ip a ti o n " i s o b ta in e d b y d e sig n in g th e
Tem trol so t h a t ■i n " c lo s e d c o n ta c t" p o s itio n ,' n o rm a l' c u r r e n t flo w th ro u g h
th e in s tru m e n t w i l l produce' a d eterm in ed amount o f in c re a s e i n b im e ta l tern®
p e r a tu r e i s j u s t s u f f i c i e n t t o cau se T em trol t o sh u t down th e h e a tin g equip®
ment b e fo re th e r e i s any a p p r e c ia b le 'in c r e a s e I n a i r te m p e ra tu re »
When th e c o n ta c ts open, " a r t i f i c i a l ” h e a t i s no lo n g e r added to th e
25
b im e ta l „
Also 6 a t th e tim e th e c o n ta c ts Openi, t h e b im e ta l i s above su r= ,
ro u n d in g a i t te m p e ra tu re by th e amount o f ilU r t i f i c a l n h e a t added d u rin g th e
tW
p e r io d .
This, r e s u lt's i n a more r a p id drop i n b im e ta l te m p e ratu re to
■
s u rro u n d in g a i r te m p e ra tu re even b e fo re a i r te m p e ratu re has s t a r t e d t o low ­
e r.
Then* w ith a v e ry sm all drop i n a i r te m p e ra tu re „ th e h e a tin g equipm ent
i s a g a in sta rte d « r '
' R e s u lts o f u s in g th e Renn T e m tro l' on a p a n e l' i n s t a l l a t i o n show :t h a t
th e h e a t a n t i c i p a t i o n .'e f f e c t o f t h i s ' in stru m e n t' i s n o t s u f f i c i e n t because
Of th e extreme' l a g n o te d w ith t h i s ty p e o f h e a tin g .
The Tem trol would Jmob-
a b ly be ; v e ry e f f e c t i v e i f u sed w ith a f o rced h o t a i r sy stem where' no ap~
p r e o ia b le la g i s n o t i c e a b l e .
'
' IISlBAfOLlS' ELECTRdlIG MQDUiW
As p a n e l h e a tin g became' more p o p u la r» an improved method o f c o n tr o l
h ad t o be ‘d e v e lo p e d . ' The o f f - o n ty p e th e rm o s ta t was found t o be in ad eq u ate
f o r p a n e l i n s t a l l a t i o n s ' because r e s id u a l h e a t ' rem ain in g i n t h e s la b paused'
th e room te m p e ra tu re t o ’’o v e rsh o o t” th e th e rm o s ta t s e t t i n g .
M im eap o lis
Honeywell a tte m p te d t o so lv e t h i s problem b y d e v elo p in g t h e i r B le c tro n ie
Moduflow system w hich a d ju s te d h e a t t o t h e room depending on changes i n out=
s id e te m p e ra tu re * c o il' te m p e ra tu re , and room te m p e ra tu re d
The system uses
e l e c t r o n i c c o n tr o l th ro u g h a b rid g e c i r c u i t and a m p lify in g system t o r e l a y
te m p e ra tu re changes t o e i t h e r b u rn e r c o n tro l's o r t o a c i r c u l a t i n g pump.
B e tte r c o n tr o l i s o b ta in e d ' by u s in g a c o n tin u o u s c i r c u l a t i o n and c o n tr o l­
l i n g th e b u rn e r o p e ra tio n b u t t h i s has th e d isad v a n ta g e o f ru n n in g th e
'
e l e c t r i c b i l l h ig h e r th a n would in t e r m it te n t'c ir c u la tio n ; consequently
i n t e r m i t t e n t c i r c u l a t i o n was used i n t h i s system i n o rd e r to . observe in su lts
rmost
V
F ig u re U
r
27
and e ffe c tiv e n e s s ; o f th e Moduflow on t h i s ty p e control©
th e e l e c t r o n i c c i r c u i t diagram o f th e Modufldw relay©
th e ModuflOW- system©
F ig u re 12 shows
This i s th e h e a r t o f
I t in c lu d e s s e n s i t i v e r e s is ta n c e th e rm o s ta ts R^g ang,
{ lo c a te d i n th e w a ll th e rm o s ta t l e f t s id e o f fig u r e 9)©
;
.- . '
.
! '
' V ,
,
I ‘ ^ I' .
•
-
•
1 -
I
I
■
.
I
.<
.
The a v e ra g in g
'
,
.
th e rm o s ta t B^g i s a w ir e ^ o u n d b o b b in r e s i s t o r t o tneasur© room te m p e ratu re ©
lh e bdbbi n i s wound w ith ' a s p e c ia l a llo y w ire t h a t changed i t s r e s is ta n c e
1 .2 ohms f o r each degree F . change on a 500 ohm b o b b in ©
■
This makes th e th e rm o s ta t s e n s itiv e t o a ' sm all f r a c t i o n o f a :degree
te m p e ra tu re ch an g e.
A f r a c t i o n o f one d e g re e i s enough t o ' t u r n on of o f f
th e h e a t so u rc es or s t a r t th e pumpo*
'
-
' ''
Ihd outdoor a n t i c i p a t o r (mounted b n th e r o o f o f Ryon l a b ) »' Rg measures
th e outdoor tem perature© ' I t c o b ta in s a r e s is ta n c e b o b b in s im ila r t o t h a t
o f th e th e r m o s ta t.
When o u ts id e te m p e ra tu re f a l l s e th e change i n ’a n tic i=
p a to f r e s i s t a n c e .r a i s e s room .te m p e ra tu re one degree f o r e v e ry SS0F t h e ' o u t­
s id e "te m p e ra tu re i s below ^O0F 0
An immersion thermostat is connected in series with the outdoor an tic­
ip a to r .
f h i s th e rm o s ta t i s lo c a te d i n an im m ersion w e ll on th e r e tu r n ' l i n e
le a d in g t o th e f lo o r p a n e l © I t s p u rp o se i s t o ’ o f f s e t th e e f f e c t o f th e '
outdoor a n t i c i p a t o r i n c ase th e p a n el "is- a lre a d y ' a t o p e ra tin g temperature
when h e a t I s c a ll e d f o r b y th e o utdoor a n t i c i p a t o r . •
f
;
/ ’
/„
R elay CR has two c o n ta c ts GRj and GRg © G losing o f CRj s t a r t s ' the pump
and GRg e n e rg iz e s th e c y c l e r .
The c y c le r d eterm in es th e d u r a tio n and f r e ­
quency o f th e h e a tin g c y c le arid p ro v id e s a minimum o f tim e o f n o t le s s th a n
th r e e and o n e ^ h a lf m in u te s .
H e atin g load i s c o n s ta n tly m easured b y th e indoor .th e rm o s ta ts and th e
38
o u td o o r a n tic ip a to r o
When,'the h e a tin g lo a d i s in creasin g ,^ th e c y c le r p ro ­
v id e s lo n g e r on and' s h o r te r o f f p e rio d s f o r th e 'pump o r h ea tin g s ounce =
C onversely# when t h e h e a tin g .lo ad d e c r e a s e s » th e " on" p e rio d s are s h o rte r#
and t h e " o ff" p e rio d s ' lo n g e r*
When h e a tin g lo ad i s c o n s ta n t# th e c y c le r
c o n ta c t opens’ 'and c lo se s ' a t - a fre q u e n c y r e q u ir e d to su p p ly h e a t to . th e room
as f a s t as i t i s l o s t t o th e . o u tsid e # and th u s i s in te n d e d ’ t o ..hofd' p ra c ­
t i c a l l y c o n s ta n t te m p e ra tu re »,
'■■■•[■ ■ ' = ■ ■ .
As an exam ple, assume t h a t th e o u ts id e te m p e ratu re i s f a l l i n g , c a u s in g
an in c re a s e i n th e h e a tin g lo a d i
R e s is ta n c e o f outdoor te m p e ratu re compen-
s a t d r Rg d e c re a se s as does th e v o lta g e a c ro s s i t ,
,S in ce th e v o lta g e ,.a c ro ss
Sg decreases',- i t m ust in c re a s e a c ro ss c y c l e r elem ent, Hg t o t u r n o f f th e
h e a t.
To do t h i s th e cycler®® te m p e ra tu re must in c r e a s e ,
B eing a t a higher
te m p e ra tu re i t w i l l lo s e h e a t f a s t e r t o t h e su rro u n d in g a i r and w i l l ' ta k e
lo n g e r t o h eat# c a u s in g t h e h e a tin g p e rio d t o in c r e a s e .
Room, tem p eratu re
i s in c re a s e d so t h a t th e rm o sta ts* r e s i s t a n c e and v o lta g e a c ro s s them in =
c re a se s,
As' a r e s u l t # v o lta g e from R t o Mg and RB t o Sfg i s s l i g h t l y low er
when t h e 1h e a t i s tu rn e d o f f th a n b e f o r e ' o u ts id e te m p e ratu re c h a n g e d ,,
■ '
Because c y c le r elem en t Hg i s a t a h ig h e r te m p e ra tu re when r e l a y OR’opens#
i t w i l l c o o l f a s t e r t o reduce i t s o f f p e r io d and t u r n o n ,th e h e a t.
In th is
way th e "on" h e a tin g p e rio d i s increased#, and th e " o ff" p e r io d d ecreased t o
meet th e in c re a s e d h e a tin g demand*
I n s t a l l a t i o n and C a l i h r a t i c n r
"
-'
,
When i n s t a l l i n g a M odutrdl sy ste # # th e "fallo w in g t i p s a re ,lh e ip fu lt
Be su re t o u se m o is tu re p ro o f w ire f o r ' a l l W1I r in g ap'd s o ld e r a l l
s p l i c e s making su re t h a t no w ire s- to u c h w hich may unbalance th e system* " ■
29
r-F IN D OUTDOOR TEMPERATURE
HERE
r-FIN D CORRECTION FOR T 7 0 0 IA 4
r -F IN D
HERE
CORRECTION FOR T 7 0 0 IA I4
HERE
i— FIND CORRECTION FOR T 7 0 0 IA I5
I I I
..................
TO FIND CALIBRATION SETTING:
90 - - ♦ !- - + 2
I. N ote and record room tem perature (at
the th erm o stat) and o utdoor tem perature
(at the W eathercaster location).
80 - -
70
o- -
O
O
60- -
3
—I- — 2
50
HERE
2. O n o u td o o r tem perature scale at left,
find o utdoor tem perature, and opposite it
on the T 7001A 4 scale (o r -A14 o r -A15,
if using one of the optional W eathercasters), read the num ber of degrees to
subtract from (o r add to ) room tem per­
ature.
40 - -
3. Add o r subtract as indicated. T h is will
give the CA LIBRA TIO N SETTIN G .
20
- -
10
0
—
-3
—
—9
6
- —
IO- --4 -
-30
------
- -
•
EXAMPLE: Assume room tem perature is
75, and ou td o o r tem perature is 30 above.
If the W eathercaster is a T 7 0 0 1 A 4 , o p p o ­
site the o u td o o r tem perature of 30 read —2.
T hen, 7 5 - 2 = 73. T his is the correct
calibration setting.
—12
- 6 - L - I O - L - is
N O TE: If the W eathcrcastcr w ere the
T 7001A 14 for this example, we w ould
subtract 4 degrees instead of 2. If it were
the T7001 A l 5, we w ould subtract 6
degrees.
Figure 13
30
CALIBRATE THE SYSTEM
I. M ove the tem perature-settin g
lever o f the T 7 0 0 0 A therm o stat
above ro o m tem perature.
2. Rem ove the dust cover and
calib ratio n -screw cap from the
relay. In se rt a piece o f p ap er b e­
tw een b o th sets o f relay contacts
in such a m anner that the p ap er
w ill not fall out.
3. Apply line voltage to T e rm i­
nals 1-2 o f the relay and tu rn the
calib ratio n screw to its extrem e
counter-clockwise p o sitio n so that
the relay pulls in. A llow at least
15 m in. before b e g in n in g Step 5.
4. Find the calib ratio n settin g as
described on Page 11 o r 10, and
change the th erm o stat settin g to
the calib ratio n setting.
5. R otate the calib ratio n screw
slow ly in the clockwise d irectio n
until the relay just d ro p s out.
6. Rem ove the p ap er from be­
tw een the relay contacts. T u rn
the c alib ratio n screw counter­
clockwise AS SLOW LY AS PO S­
SIBLE u n til the relay just pulls
in. Put the screw cap and the
dust cover back on, and check
the o p e ra tio n .
Figure 14
SI
Mount th e th e rm o s ta t about fiv e f e e t above th e f lo o r on an in s id e w a ll,
a v o id in g hot s o o ts .
L ocate th e r e la y on e. s o lid v e r t i c a l s u rfa c e where am bient te m p eratu re
never exceeds 120 F .
Locate th e o u ts id e a n t i c i p a t o r p r e f e r a b ly i n th e shade on th e n o rth
s id e o f th e b u ild in g where i t w i l l be p r o te c te d from damage or r a d ia n t effect
from th e b u ild in g .
A fte r a l l i n s t a l l a t i o n i s com pleted th e system must be c a l i b r a t e d .
The s te p s i n c a lb r a ti o n a re shown i n F ig u re 13 and F ig u re 1 4 .
COMPOSITE ELECTRICAL DIAGRAM
I n s e t t i n g up t h i s la b o r a to r y i n s t a l l a t i o n , i t was n e c e s sa ry to arrange
v a lv in g and s w itc h in g o p e ra tio n s so t h a t v a rio u s o p e ra tio n s oould be con­
d u c te d w ith o u t changes i n p ip in g or w ir in g .
F igure 15 shows a lin e type
draw ing o f e l e c t r i c a l c i r c u i t s used w hile F igure 10 shows a p i c t o r i a l c lo seup o f th e e l e c t r i c a l c o n tr o l p a n e l.
At th e l e f t s id e o f F ig u re 10 i s shown a Trumbull s w itc h which is
m erely a m a s te r, fu se d sw itch c o n tr o llin g power t o th e whole p a n e l.
Located
im m ediately below i s th e sumo pump sw itch which is m anually o p erated to
d r a in th e sump whenever th e system i s b e in g d ra in e d o r w eig h in g o p e ra tio n s
are ta k in g p lace#
D ir e c tly above th e Trumbull sw itc h sw itc h i s a fo u r p o s itio n r o ta r y
sw itc h used to sw itc h o p e ra tio n o f c i r c u l a t o r from one s e t o f c o n tro ls to
th e o th e r .
The fo u r p o s itio n s a r e ; o f f , manual o p e ra tio n ( c i r c u l a t o r ru n ­
n in g c o n tin u o u s ). E le c tr o n ic Moduflow, and Penc T em tro l.
C onnected t o th e to o r i g h t o f th e Trumbull sw itch i s a s in g le c o le .
52
PENN.
THERM
HI GH
L(M)T
LO- L I Ml T
MOD
T H f f f l MO S T A T
IIOV IN
MODUTROL
Su m p
pump
CI RC .
E L E C T R I C AL
Figure 15
PUMP
C I R C U I T S
33
'£' 'Botitileethraw ■s w ite h . t o change c o n tr o l from manual one r a t io n t o M o d ^lW o r '“
!
.
•
1
'
-
'
'
. '
Below t h i s s w itc h i s a s in g le p o le , s in g le -th ro w sw itc h w hich s u p p lie s
power t o o p e ra te th e M odutrol when i p th e ” on” p o sitio n * .
When o p e ra tin g th e M odutrol on p a n e l o p e r a tio n , th e r o t a r y s e le c to r
sw itc h m ust be i n th e M odutrol p o s itio n *
^he ’'pow er-on" s w itc h t o th e
M odutrol must be "on” , and th e d o u b le -th ro w sw itc h must be i n th e "Motiut r o l " o r "up" P o s i t i o n 0
W hile th e sy stem i s o p e ra tin g th e p a n e l w ith th e Penn Ie m tro l c o n t r o l ­
l i n g , th e r o t a r y sw itc h m ust be i n "therm *" p o s i t i o n , th e double pole switch
i s i n th e " o f f " p o s i t i o n .
P u rin g b o i l e r t e s t s and o th e r t e s t s n o t c o n ce rn in g th e p a n e l, th e r o ­
t a r y s w itc h i s p la c e d i n th e "manual" p o s i t i o n , th e double p o le sw itc h i s
i n th e "manual" p o s i t i o n , and th e s in g le s o le sw itc h i s " o f f " o
.W iring uspd in. th e sy ste m i s p l a s t i c c o a te d , s in g le c o n d u cto r w ire i n ­
s id e th in - w a lle d c o n d u it,
th e c o n d u it i s p a in te d re d to in d ic a te t h a t dan­
ger m ight be in v o lv e d i f tam pered w ith ,
•"
A w ir in g r e v i s i o n c o u ld be added t o t h i s system so th e pump would
i
■ ■'i !
j•
'
■ •
';
»
' '
I
•
tt
o p e ra te c o n tin u o u s I y 0 w ith th e r m o s ta tic c o n tr o l sw itch ed t o b u rn e r opera®
• " ■''
'■i' - V, : v 1I ,
;I". ■
■1 ■■ ■ .
,
..
,
tio n .
% i s r e v i s i o n wpuld p re s e n t a n o th e r 's e r ie s o f t e s t s f o r th e f lo o r
p a n e l w ith o n ly m inor changes t o th e sy ste m .
' CHAPTER I I I
RARBR ORBRAgIOR
I n tr o iHuQtion; •
The purpose o f any h e a tin g system i s t o p ro v id e 'co m fo rt fo r th e Odcu=
p a n ts o f th e b u ild in g . ■ As c o n v e n tio n a l system s d i s t r i b u t e t h e i r h e a t m ain­
l y by o o n v e o tio n , th e body i s surrounded, by a i r warmed t o te m p e ratu res t h a t
make th e room f e e l c o m fo rta b le .
This f e e l i n g o f com fort i s b ro u g h t about
by th e warm a i r govern in g th e r a t e o f h e a t lo s s from th e body©
The p rim a ry f u n c tio n o f R ad ian t P an el H eatin g i s t o keep., people oom=
f o r t a b l y warm by h e a tin g th e c e i l i n g , f l o o r or w a lls o f th e room, and <hsek®
in g th e body h e a t l o s t by r a d i a t i o n t o c o ld room s u r f a c e s .
A dvantages c laim ed f o r t h i s ty p e o f h e a tin g a re f
I.
More f lo o r space a v a ila b le and th e e lim in a tio n o f u n s ig h tly r a d i ­
a to r s , g iv in g a room a more sp a c io u s appearance .
2o
Ho r e s t r i c t i o n i s p la c e d on f u r n i t u r e a rran g em en t.
3 , . There id le s s s tr e a k in g and d u s t on w a lls and c e i l i n g due t o lo w er
v e lo c itie s , o f a i r c u r r e n ts ’a nd a laofc o f h ig h te m p e ratu re c o n cen t
tr a tio ti e
4 0 S im p lif ie d s t r u c t u r a l d e sig n e lim in a te s d u s t sp aces and r a d ia to r
re c e s s e s > th u s re d u c in g f i r e h a z a rd s .
5«• Perm its- re -a rra n g e m e n ts o f p a r t i t i o n s .
6.
R a d ia n t system s a re th e o n ly ty p e t h a t does away w ith c o ld f l o o r s
I n b a se m e n tle ss homes—th u s b e in g ad m irab ly s u i t e d f o r s la b ty p e
c o n s tr u c tio n .
The f l o o r p an el u sed t o h e a t Room Ho. 9 i n Ryon la b o r a to r y has th e
c o n s tr u c tio n as shown i n F ig u re 16 and F ig u re 17«,
Ihe c o i l s a re composed
o f one in c h s t e e l tu b in g l a i d on tw elv e in c h C e n te rs 0
" P ig c u s slo h o f t e s t 'p ro c e d u re s
^
She room t o be heated' by r a d ia n t f l o o r p an els i s '24® -4 ” by
'
■■ ■
'
_. '
silide d im e n sio n so .The w a lls a re 15* h ig h e x c lu s iv e ’ of s k y lig h t S e c tio n 0
;
-
1
,
. . . . . .
.
The w e st s id e o f th e room M s a window I S 6-S '1 by 9 ' -S11 i n s iz e ?
1 <-
' *
'
I
1
t
1
.
'
, '
;
....
The' th re e , ,
-I
,{•" ■
in s id e w a lls a te composed o f hollow c o n c r e te 1b lo e h s w h ile th e O u ts id e 'w a ll
i s o f b r i c k , 8" th ic k *
The s b u th s id e of th e room has i n c lin e d s k y lig h ts so t h a t on sunny
d a y s , th e su n 1lo a d i s v e ry h ig h 6
This and th e f a c t t h a t th e w a lls o f th e
room 'do n o t go a i l th e w ay' t o th e c e i l i n g p re s e n ts a d i f f i c u l t h e a ti n g
problem s
T ests w ere conducted J is in g two. d i f f e r e n t ty p e s o f c o n tro ls to
r e g u la te p a n el o u tp u to M inneapolis M odutrol and th e PexnrTem troI"w e re .■the,
'i :' / . ■ . : - - '
tw o ty p e s u'se'de
• v'
'
,
1
For p urposes o f mea s u f ih g /tem p era tu re s d u rin g th e p e r io d o f c o n d u c tin g .
th e t e s t s » a Foxboro Bynalog re c o rd in g therm om eter was usedo ■
The m u lti ^ re c o rd Bynalog may be u sed t o ’re c o rd up t o s i x d i f f e r e n t
te m p e ra tu re s a t th e same tim e on th e same re c o rd in g d isk o
T his i s made •
p o s s ib le by th e use o f a d i f f e r e n t pen f o r each c o lo r o f in k so t h a t ho eon=
f u s io n w i l l r e s u l t when i n t e r p r e t i n g th e c h a r t .
The li n e s a re re c o rd ed as
m in u te » c l o s e l y , spaced d o ts p r in t e d a t th e r a t e o f one e v e ry s i x seco n d s,
Tem peratures ta k e n w ith th e Bynalog w ere re c o rd ed u s in g s u rfa c e terns
■
p e ra tu re r e s is ta n c e b u lb s w hich a re a p o stag e stamp s iz e d w a fer w ith a
.
r e s is ta n c e c o i l i n s i d e .
These b u lb s have th e a b i l i t y t o r e a c t v ery r a p id ly
t o changes o f te m p e ra tu re ,
36
2 " CONCRETE
TOP
tubes
CENTERS
SE C TIO N
THROUGH
F lO O R
F ig u re 16
F I GUR E 17
panel
d ia g r a m
37
Temperatures re c o rd e d f o r the. ''e d rie e o f t e s t s eons i s t e d o f tem pera­
tu r e s a t th e i n l e t and. o u t l e t t o t h e ' p a n e l, f l o o r te m p e ra tu re a t a r e p r e ­
s e n t a t i v e I d e a t i o n , room te m p e ra tu re ■o f -the room j u s t S o u th o f th e room
^
■ I
•
1
I ,
■ ■
u n d er p a n el o p e ra tio n *
-
Outdoor temperature -was re c o rd e d by use o f a n o th e r
in s tru m e n t da th e B o rth w a ll o f Ryon l a b a t o r y »
mm" GivBB opp BY pvdm
•
■
■
■
'■
.
■ •
■
■
................. ..
, .
.....
...................
,
1
...................
■■
The h e a t t r a n s f e r from a , p an el i s aeeom pliehed by two b a s ic h e a t
t r a n s f e r p ro c e ss e s t V adiationftjand c o n v e c tio n .
The r a d i a t i o n t r a n s f e r c an he e v a lu a te d ■by m an e o f th e r e la tio n s h ip
s e t up by S te f a n and BO tzaann5
w here '
' qr
h e a t' t r a n s f e r by r a d ia tio n * B t u / f t ^ / h r «
Ts - a b s b lu t e ’te m p e ra tu re Of p a n e l h e ate d s u r f a c e „ 0F.
Tw 2 a b s o lu te mean r a d ia n t te m p e ra tu re o f a l l u n h eated s u r f a c e s ,
:
'
O
y 0
■
•
■
■
.................................................
,
_
Fa s c o n fig u r a tio n fa c to r (d im en sio n less)*'
Fg V e m is s iv ity f a c t o r (d im e n sio n le ss) *
For la r g o ' p a r a l l e l ' p la n e s ■b r ' I a r g e 1e n b lo se d ' s u rfa c e s as o r d i n a r i l y ■
e n co u n te re d in ' p a n e l' h e a tin g ' p r a c t i c e '
■* 1•>■
Fe = ___ I.......... .................................
.
where
-
S ih r 2 - 1
;
.
■
-
■ >
and eg e q u a ls e T n is s iv itle s o f th e ' re s p e c tiv e s u r f a c e s «
I n h e a tin g p r a c t i c e P 1 and eg a re u s u a ll y e q u al t o 0*9 and F@ t o 0.82«
The c o n f ig u r a tio n f a c t o r Fa I s e q u al t o 1 .0 f o r la rg e p a r a l l e l p la n e s .
38
T h e re fo re , f o r o rd in a ry room s, th e e q u a tio n may be s im p lif ie d t o ;
q^*- S- O oH sJ
An average f l o o r s u rfa c e te m p e ra tu re o f IOO0Fo was assumed i n c a lc u ­
l a t i n g p a n el r a d i a t i o n output®
This assu m p tio n was made from v is u a l i n ­
s p e c tio n o f Figures 18 and 19«
I t i s fu rth e r assumed t h a t th e mean radi®
a n t te m p e ra tu re o f a l l u n h e ate d s u rfa c e s i s ,60°F»
i ii'>r*'i{Ir‘ . <■
3f / 560X4=/«
t h e r e f o r e ; qr g 0»1421/5
6 0 ^ ° /5 2 0 \ * | - 0 ,1 4 2 (985 - 730) - 36 ,2 B t u / h r / f t 2 ,
[(looJ
IW
J
O ohvection i n a p a n el h e a te d :s p a c e i s u s u a lly c o n s id e re d t o be o f th e
n a tu r a l ty p e 0 t h a t is # a i r m otion i s ■g e n e ra te d by th e w arm ing o f th e bound­
a ry la y e r Of a i r w hich s t a r t s moving as so o n as i t s te m p e ra tu re exceeds
t h a t o f su rro u n d in g , a ir ..
I n f i l t r a t i o n # v e n t i l a t i o n , . and.movement o f p e r ­
sons a re a l l f a c t o r s . l i k e l y t o d is tu r b th is , .process# s o i t i s d i f f i c u l t t o
determ ine th e e x a c t1c o n v e c tio n e f f e c t ,
,
Vt ■
v
,
\
The b a s ic e q u a tio n f o r n a tu r a l o o n y e o tip n from a f l a t s u rfa c e i s o f
th e fo llo w in g for^m:
9* : ?o ("Sg - V *
where
q
= h e a t t r a n s f e r b y co n v ectio n # B t u / f t ^ / h r ,
,
■,1 .
•,
i. ■ ,
•
i
I
' i
i
, •■ »
.
1 ‘.
». ,
^i
,. '
*^
• I
•
Fq E a c o e f f i c i e n t (s u rfa c e conductance) r e p r e s e n tin g th e h e a t
t r a n s f e r from a u n i t a re a p e r u n i t d if f e r e n c e i n te m p e ra tu re ,
n
s an exponent depending upon s u rfa c e p o s itio n .and te m p e ratu re
■" 1
•
■ ■
■
' ' '
■' '
d if f e r e n c e betw een th e s u rfa c e and th e su rro u n d in g a i r ,
.
tg = te m p e ra tu re o f th e s u rfa c e # 0F 6
t a - te m p e ra tu re o f th e a ir # 0Fp
V alue o f "n ” i s ta k e n as 1*12 f o r low te m p e ratu re d if f e r e n c e and h e a t
flow upward from h o r iz o n ta l s u r f a c e s .
F
V aries from 0 oS8 t o 0 ,8 1 f o r upward h e a t from f l o o r s 0
The fo re g o in g e q u a tio n may now be changed t o :
■
.qe ® O08I (tg - t a) lo lS »*—fp r f l o o r p an els
'
'
....
- 1
t h e r e f o r e : q - o ,8 1 ( 100~70)1<>13 1 O0S l (45) » 3 6 ,5 B t u / h r / f t 2
The t o t a l h e a t t r a n s f e r from th e f l o o r p a n el i s
th e r e f o r e : Qs A ( q ^ q r ) g (811) (36o2 + 36o5) : (811) (72 e7) ° 53 ,950 B tu /h r ,
mar loss fece boom
The d e s ig n o f h e a tin g S ystem s' f o r b u ild in g s re q u ire s , a' knowledge o f
th e th e rm a l' p ro p e rtie s ' o f th e ' w a lls e n c lo s in g th e s p a c e .
The r a t e o f h e a t
flow th ro u g h the' w a lls under s te a d y “s t a t e , c o n d itio n s -at d e s g in te m p e ratu res
i s .u s u a lly th e b a s is f o r c a l c u la tin g th e h e a t r e q u ir e d .
For a given w a ll
under s ta n d a rd c o n d itio n s th e r a t e i s a s p e c if ic v alu e d e s ig n a te d as "B ",
,
■'.
' ''
>
•
'
th e o v e r a ll c o e f f i c i e n t o f h e a t tr a n s m is s io n .
The room h e a te d by th e sy stem d e s c rib e d i n t h i s t h e s i s has a t o t a l
g la s s a re a o f 199. f t 2 , a t o t a l c e i l i n g a re a o f 858 f t , o u ts id e w a ll area
237 f t 2 , and t o t a l p a r t i t i o n a re a ( in s id e w a lls ) 1182 f t “ a
The in s id e w a lls do n o t re a c h c o m p le te ly to th e c e i l i n g on two s id e s
so a la r g e J!i n f i l t r a t i o n f a c t o r ” m ust be u sed t o acco u n t f o r lo s s e s th ro u g h
th is a re a .
C o n s tru c tio n i s as fo llo w s 5
C eiling*— — — >— -“i s ” h o lo r ib deck co v ered w ith 1” o f in s u la tio n
and to p p e d w ith r o o f e r ’ s t a r ,s a tu r a te d f a b r i c .
b g 0o24
O utside w a l l - — ——-12'' s o l i d b r i c k c o n s tr u c tio n .
U
I n s id e p a r t i t i o n s —”8" th ic k hollow c o n c re te b lo c k s .
OftSS
C m Q036
40
(ylase: a r e a — --------.-sin g le p a n e ,
..... ...M ■-
XJ © Io lS
, .,.... f/
q .s
w here
^ a < ii °
Q = B tu /h p to
U e over a l l o c s f f i e i e 'n t o f h e a t t r a n s f e r .
in s id e te m p e ra tu re (assume 7G°F«)
t 0g o u ts id e te m p e ra tu re (assum e S-SO0S1o) . - , •
th e r e f o r e ;
Q g 0 P36 (2S7) (90) g 7080 B tu /h rp . ■
Boss th ro u g h g la s s a r e a ;
Q s
( I =13) (1,99) (90). « 20»820 B tu /h r»
Loss th ro u g h s e l l i n g :
Q S(0 .2 4 )(8 6 S > (9 0 ) s 1 8 e500, B tu /h r 0
I n f i l t r a t i o n lo s s s - ■
Due t o Open sp ac e s above th e p a r titio n , w a l l s » I n f i l t r a t i o n , i s . assumed
t o be th r e e changes o f a i r p e r h o u r.
She lo s s i s to o th e r rooms i n th e
b u ild in g w ith a te m p e ra tu re • d if f e r e n c e o f S0F . assumed=
» i n f . S4>.e l ®
‘ t= )
9
» a ir e n te r in g (ou» f t ./h r = )
t^
room tem perature—TO0F =
tb
'
.£ h a l l temperature =—assume;65°F=
th e re fo re ;
Q in f , = OoOlB(3 9 ,6 1 8 )(8 ) » 5570 B tu /h r =
Loss th ro u g h w a lls t o o th e r room s:
Q S (O =Sp)(IlB S)(S) a 2 l i o B tu /h r p
41
Summation o f h e a t l o s s ; .
Adding a l l o f th e lo s s e s to g e th e r g iv e s a f i n a l f i g u r e ’ o f 52,IQQ
B tu /h r , as th e t o t a l h e a t lo s s from th e room under d e s ig n c o n d itio n s o f
TO0Fo in s id e te m p e ra tu re , =BO0P . o u ts id e te m p e ra tu re , and a w ind v e lo c i ty
o f 15 m i l e s / h r .
RESULTS OF PANEL TESTS'
i
■ "
.
R e s u lts o f th e two p a n e l h e a tin g t e s t s o f t h i s i n s t a l l a t i o n a re shown
i n F ig u re s 18 and 29»
T ests show th a t, r e g a r d le s s o f th e w e ath e r o u ts id e ,
su n lo a d had an a p p re c ia b le e f f e c t oh h e a tin g th e room,^ due to ' th e lo c a tio n
o f th e overhead s k y l i g h t s » I f th e S k y lig h ts fa c e d N orth in s te a d o f S o u th ,
th e e f f e c t o f sun lo a d would be re d u c e d .
Tem perature in d ic a tio n s i n th e
A rc h ite c ts room, w hich was u n h e a te d , show th e e f f e c t o f 'aun lo a d t o be th e
d is tu r b in g f a c t o r i n t h i s sy ste m .
1.
F a c to rs c o n tr ib u tin g t o th e e x c e s s iv e la g o f th e sy stem a re th e la r g e
s iz e p ip in g u sed i n th e f l o o r and th e d ep th th e p ip es a re b u rie d i n epn»
o r e te (6 i n c h e s ) .
A la r g e h e a t r e s e r v e i s b u i l t up b y th e c o n c re te and
la r g e volume o f w a te r i n th e c o i l s , in tr o d u c in g la g i n t o th e system c o n tro l.
I n o rd e r t o keep th e room a t a c o m fo rta b le le v e l th e f l o o r te m p e ra tu re
had t o go as hig h a s I l d 0F , , w hich cau ses d isco m fo rt t o th e o c cu p a n ts,
e s p e c i a l l y s tu d e n ts ' who m ust rem ain s e a te d i n one s p o t d u rin g th e co u rse o f
' a le c tu re .
I n v e s tig a t io n has. re v e a le d ' t h a t te m p e ra tu re s on f lo o r p a n e ls
sh o u ld n e v er exoeeld 90®?, t o m a in ta in p ro p e r fo o t c o m fo rt,
Both c o n tr o l sy ste m used show a la c k o f a b i l i t y t o m a in ta in c o n s ta n t
te m p e ra tu re i n th e r Oora0
The Moduflow has an approxim ate f i r s t c o s t o f
1 1 0 6 .5 0 , w h ile th e Penn Tem trol w ould c o s t ap p ro x im ately #22,00»
The d i f -
42
P f 7NtiJ
TH£RMO?TAT
( J a H , * cy 7 J m-)
•
f
ilitjHi Egjjfi.
Iq
rs;
S
v 'ovc*y —F i!
FLOOR
\
HOT
COIL
rtM f>
R oom
Ou t d o o r
hours
Figure 18
LfG
43
EL EC;TRONIC
f
S e H I.r 4
MODUFLOU
-
7 ' °?
, OV
p VM P
FLOOR
N HOT LEG COIL
OUTDOOR
Figure 19
44
fe re& e s
tr o l
in
c o st does
a b ility
o f th e
n o t ■s e e m
ju s tifie d
fo r
th e
s m a ll
d iffe re n c e
in
Q on=
tw o s y s t e m s o
I n C hapter f iv e a sy stem i s d escrib ed , w hich would be a b le to handle
r a d i a n t h e a tin g problem s b e t t e r i n sm all homes, e s p e c i a l l y i n any c lim a te
w ith extrem es o f te m p e ra tu re c a l l i n g f o r a more r a p id re sp o n se t o o u t­
s id e c o n d itio n s o
45
CHAPTER IV
TESTING
I a t r od u ctio n ;
I n a d d itio n t o h e a tin g a room by r a d i a n t p a n e ls » th e b o i l e r I n s ta l=
l a t i o n i s a ls o u s e f u l i n c o n d u c tin g o th e t t e s t s 0 This c h a p te r shows a
sam ple b o i l e r t e s t and a sample c o n d u c tiv ity o f h e a t ex changer t e s t made
u s in g equipm ent i n s t a l l e d a t th e p r e s e n t tim e »
Sample c a lc u la tio n s shown i n t h i s c h a p te r a re f o r i l l u s t r a t i o n o n ly
and do n o t e x p re ss any i n p l i o a t i o n t h a t th e y a re th e f i n a l r e s u l t s o f t e s t =
in g t h i s u n it*
Changes w i l l b e made from tim e to tim e i n u s in g t h i s equip=
Eiant t h a t w i l l b r in g e f f i c i e n c i e s c lo s e r t o th e d e s ir e d I e v e l e
BOlBER TEST
Summary:
The e f f i c i e n c y t e s t was conducted on th e American S ta n d a rd b o ile r o f
th is in s ta lla tio n *
D u ra tio n o f th e t e s t wap one hour and from d a ta ta k e n
w ith r e f e r e n c e t o flo w , p r e s s u r e .» and te m p e ra tu re o f th e. f u e l , and w a te r
flow and te m p e ra tu re change,, c a lc u la tio n s w ere made t o d eterm in e th e h e a t
d e liv e r e d by th e b o i l e r as compared t o h e a t consumed d u rin g th e t e s t .
V arious p o s s ib le lo s s e s a re a ls o shown i n sample c a lc u la tio n s e
B o ile r e f f i c i e n c y ' f o r th e p a r t i c u l a r t e s t shown was d eterm in ed t o be
68$,
This i s compared w ith th e m a n u fa ctu rers r a t i n g o f 80$ © fficien cy o
V arious e r r o r s i n t e s t p ro ced u re c o u ld a cco u n t f o r t h i s low e f f ic ie n c y
w hich i s due * no d o u b t, t o in a c c u ra te t e s t d a t a .
Two o f th e p la c e s where
i n a c c u ra cy o f t e s t i n g c o u ld e n te r a re $ ( I ) An. e r r o r i n w a s Ured .gag con=
sum ption due t o th e therm om eter w e ll b e in g lo c a te d a d ja c e n t t o th e h o t
46
w a te r I I mq- p o s s ib ly c a u s in g an ©rroneouai re a d in g o f t h i s thermometer=
'
(2) The therm om eter w e lls lo c a te d a t th e : b o i l e r i n l e t and o u t l e t a re i n a ;
p o s i t i o n w here r a d i a t i o n from th e b u rn e r c o u ld In fM e n ee t h e i r re a d in g s .
I t is'.recom m ended‘t h a t th e h o t -water .pipes' i n t h i s area be in s u la te d ,
Purpose
' ••
•
The purpose o f c o n d u ctin g th e s ta n d a rd b o i l e r t e s t i s t o determ ine
b p i l e r e f f i c i e n c y and a ls o t o account f o r any lo s s e s t h a t m ight occur i n
.
c o n d u c tin g a . t e s t - o f t h i s type,, :
Procedure :;
■
"
.......................
■ 'Y 1
1
.
\
Duping th e t e s t , d a ta were o b ta in e d f o r f u e l flo w , p re s s u re and temp
1 ■■ p e r a tu r e » w a te r temperature (both: e n te r in g and le a v in g th e -b o i l e r ) ; pres®
. ■s u re drop acr'pss th e o r f io e i n the w a te r - l i n e ; a i r te m p e ra tu re and humidi®
-'
■
.
' ■1
'
■-'V ' - - ■
, t y s s ta c k , te m p e ra tu re g and an o r s a t a n a ly s is o f p ro d u c ts o f combustion,
From t h i s - d a t a , 'c a lc u la tio n s were-!made- t o d e te rm in e -h e a t tr a n s f e r r e d ''
t o w a te r ■flo w in g -through th e b o i l e r , h e a t lo s s t o dry f lu e g a s , h e a t l o s s '
t o m o istu re ■i n th e a i r ,, h e a t ■l o s s . t o H ioisture from h y d ro g e n -in th e - f u e l,:
and t o t a l h e a t s u p p lie d t o th e b o i l e r »
R e s u lts ;
-
'
R e s u lts o f c a lc u la tio n s a re shown below :
’-|^>at ■t
o
-
w
a
t
e
-- r
7S ,450 - ! B tu /h r @
B eat t o m o is tu re ' i n th e a i r - - ” =-*-—-—"-V -B o a t-lo s s ■t c d ry f lu e g a se s—
Heat lo s s to .h y d ro g e n m o is tu r e - —- ——
—
T o ta l h e a t accounted- for*=—
B oss due t o r a d ia t io n and Unaocounted—
rg
4 0 .2
Btu/hr.o-
S0SOO
B tu /h r »
11,030
B tu /h r ,
90,320 .
B tu /k r ,
B tu /h r d
47
■Hbat in p u t t o b o i l e r - - - —
'B o ile r offi oi ezi oy*' ?-—
108, 000
•, BtuyZhr>
68^ ‘
T h e re .is a h e a t lo s s o f 17,680 B tu /h r . i n th e sy stem t h a t can n o t be
accounted, f o r c
F u r th e r t e s t s . i n th e fu tu re , may show w here m istak es a re be?
in g made i n t e s t p ro c e d u re » Hotirever „ th e b o i l e r does g iv e a s a t i s f a c t o r y
perform ance f o r p u rp o se s o f s tu d e n t in s tru c tio n ®
48
Sample t e s t d a t a :
Boom. Tptitjis'
SOB'.'
- B a^om atrio B re s s tro 2 6 .1 6 in .h g .
'
Wet B u i t :
1 5SPo
!
'■ O rfic e C o sf: OoSI
'
■ S ia m 'o f O rfio e V 0.877*
V.'.'fiao
f oiitp.
' 88P
88 ' .
.$ 8
'
.
L' ' "" ""
- Gas ' ■
Flue
Ife te r
o u . f t / j i r . temp
-O rfie e '
p re s s u re '
liE2O
•'
116i>5': ' \ 1 4 3 .5
1 1 9 .5
320
5 .1
1 1 6 .5
1 4 3 .5
1 1 9 .5
320
HS.5
325
. 3 ;08
320
3 :1 8
330
■ 3 :4 1
'
•
■ 144' '
117
■1 4 4 .5
1 1 7 .5
'
Temp' • ■
O u tle t
•
5 .1 " MO
: 1 1 9 .5
■ 145'
1 1 8 .6
S 6I
.
................
' '
W a te r:
liile t
5 .0
.
'
BresgUro
' 5 .0 '
&8
vJ
" '
'
'
'
: 3,.8
3 .7 5
tim e ’
, .2:;3.5:
2 ?50 -
OBsat A nalyzer r e s u l t s
r —“
1
“
, ,, -TTr
II
; GO • • !■O2 ■■
‘' "r.
'/
I
«.«
I ■v’
■!.
8*6%
14 #6 ' 1 4 .6
' 8 d5 ' ' 14'.S' ■1 4 03 .
■■8 .6
'
■ ■1■■
' 1 4 .3 ■ 1 4 .3
...................... .
.
'
,
. .
• 5:
.
•
'
’
•
^
■
'
.
:
'
49
SMFLE CALOELATIGIS
'Eiiese c a lc u la tio n s are. th e r e s u l t o f one t e s t .
T e s t s 't h a t may be otin®
d u cted a t o th e r tim e s may n o t ag ree e x a c tly ' w ith th e s e r e s u l t s .
B eat t o w a t e r ;
S ince a s h a rp edged or f ic e warn u s e d t o measure th e ifI Ow1Tthe f i r s t
s t e p i s to determ in e th e pounds o f w a te r b e in g c i r c u l a t e d p e r hour i n th e
sy ste m .
The g e n e ra l e q u a tio n f o r t h i s i s :
q - QA^JZgh
q = ft^ /s e c
A s a rd a o f o r f i c e i n f t ^
O ® 0 ,6 1 ( o r f ic e c o n s ta n t—f o r t h i s p a r t i c u l a r s h a rp edged o r f ic e )
g a g r a v ity f t , p e r s e e , p e r see*
h « p re s s u re head (manometer r e a d in g ) ' i n f t .
q S ( O ^ l ) A i STT)2) /6 4 .4 ( 3 ,8 \
X M S tr/V :
m )
,
v ,,
. ,
q» ,0116 ftV s e c 'o .
ws ( .0116) (3600) (615) g 25T0 I b s / h r l
Ayg. temp", o f BgO » ,ISO0F
Avg. w t. o f I f t 5 BgO @ 130°F » 62,425 ,.- 61.,5 l b . / f t 3
'
,
I ,01423
I r o m w e ig h com parison t e s t made i n th e ex ch an g er t e s t c th e m eter i s read®.
in g 5,6% le w ,
T h erefo re ,.the c o r r e c t w a te r fle w i s 2 ,TZQ ylb./h r .
Qto WSLter g q ( d t j s 2T20 (144=117) '» 73,450 B tu /h r . ,
B eat i n p u t :
'
.
. ..
'
The gas in p u t must f i r s t be c o r r e c te d t o com pensate f o r changing
in p u t due t o b a ro m e tric changes! v t a p i tp ® 2 5 ,5 ( 1 ) (S2@) s, «822 f t 3/ f t 3
Pg
540 (2 9 .9 2 )
so
T h e re fo re ;
s 1 1 9 .5( 0 .8 2 2 )(1 1 0 0 ) g IOS0OOO B W h r>
■■
■■
’■ »
H igher h e a tin g v a lu e o f 1100 B tu /ft® i s u s e d ,
E ffd jo ien ey s
,■
o
S
73,450 g o68 o r 68^
Loss due t o m o istu re i n th e a i r :
For p urposes o f d e te rm in in g th e s e r e s u l t s ehem ieal c o m p o sitio n o f th e
f u e l gas by volume, we® assumed t o be
and CgHg9 p ro p an eo 3%o
m ethane0 filfoi' C2Hg» •e th a n e » 6%?
The m o le c u lar W eight o f n a tu r a l gas (a v .) i s 1 8 Q
% e s p e c i f i c h e a t a t c o n s ta n t p re s s u re f o r -water vapor i n t h i s te m p e ratu re
range i s Op = 0 .4 6 B t u / l b / 3? .
The f i r s t s te p o f t h i s p ro c e ss e n t a i l s fin d in g th e mols bf' esh a u st/m o l
o f f u e l by a carb o n b a la n c e .
o91CH4
.
+ o06Gg^6 + oOSOgH
.91(12) + .06(24) + .03(36)
o08600g
.086(12)%
1 3 .S ^ lo03x
x ® 13.1 Mols e x h a u s t/m o l. f u e l
The o r s a t a n a ly s is i s n e x t u se d f o r f in d in g pounds o f e x h a u s t p er mol ex@
h au st
; —^ .086 OOg + .06 ©g + 0 .8 5 4 Hg
.
.086(44) 4= .0 6 (3 2 ) + .854(28) % 2 9 .6 l b . ex h au st/m b l e x h a u st
1 3 oI % 2 9 .6 s 2 1 .5 l b .e x h a u s t/lb f u e l
S in c e . one pound o f f u e l was burned we can s u b s tr e c t One from 2 1 .5 and g e t
2 0 .5 I b . a i r / l b . f u e l
'
. The n e x t s te p i s t o determ in e how much th e n a tu r a l gas w eighs p e r
lVti-
c u b ic f o o t ,
Xhis a ls o r e q u ir e s a knowledge o f c o r r e c te d b aro m etric, p res=
s u re added t o th e manometer re a d in g ;
# T PT - ( 2 5 .5 ) (lK#»o49l)(144) - .0384 l b , f u e l / f t 5
V ft
1544 (548)
°
~18~ ' '
M u ltip ly in g l b . f u s i / f t ® tim e s f u e l r a t e p er hour d eterm in es th e number
o f pounds o f f u e l u sed p e r hour
,
.
( o0384)(1 1 9 .5 ) g 4 .5 9 l b . f u e l / h r i, •
.
■
,
K oxt9 Icnowing th e f u e l r a t e , and pounds o f a i r p er pound o f f u e l consumed i n
th e b u rn e r we can o b ta in th e number o f pounds o f a i r u sed p e r hour .
( 2 0 .5 ) (4 .5 9 ) 2 94.3 l b . a i r / t o . Knowing th e d ry and w et b u lb te m p e ra tu re o f th e room and u s in g th e p sy c h ro m e tric c h a rt* th e r e l a t i v e h u m id ity was found t o be 17 / .
Xhe p re v io u s c a lc u la tio n s have b een n e c e s s a ry i n o rd e r t o o b ta in in®
fo rm a tio n le a d in g t o th e f i n a l s o lu tio n o f h e a t l o s s . t o m o istu re i n th e a i r
\
and f o r o th e r s o lu tio n s t h a t fo llo w .
Severns and D ie g le r l i s t s th e fo llo w in g e q u a tio n f o r use i n determin®
in g m o istu re lo s s s
.H ® Wv x .4 6 ( t g ® t &)
H g B tu lo s s p e r pound Of f u e l .
'
1
Wv s r e l a t i v e h&midity e x p re ss e d as a decim al *
x w t . o f w a te r vapor t o s a tu r a te I pound o f d ry a i r a t t a . x ,w t.
^
.
o f d ry a i r u sed p er pound o f f u e l fire d *
t a ~ te m p e ra tu re o f e n te r in g a i r t o f u r n a c e .
tg® te m p e ra tu re o f gases le a v in g fu rn a c e
H ® (.1 7 ) (.0222 6) (2 0 .5 ) (.4 6 ) (32 5®80)
62
E « 8o75
ef u©! —
!
8 o75 x 4 =59 g 40«2 B tu /h r = l o s s due t o m o istu re =
.H eat lo s s to , d ry f lu e ' g a s 's
B
-
= *dS Op (*g
S
" s B tu l b s s /pound o f f u e l . ■
W^g
-'wfci o f d ry gas a t b o i l e r o u t l e t » lb o /lb = fu e lo
Gp
- s p e o if ib r h e a t o f d ry g a s a b o u t 0 ,2 4
H
: ( 2 1 ,5 ) (0 .2 4 ) ( 3 2 5=80) » 1256 B t u / l b . f u e l
or (1 2 6 5 )(,0 5 8 4 )(1 1 9 ,5 ) = 5800 B tu /h r .
H eat lo s s t o hydrogen m o is tu r e :
H =.-9
(1089,1 - t o46t
y
- •
- t ) when t
6
<[ 57SP,
■H '"=■ B tu lo se p e r pound o f f u e l .
By' = W e i g h t o f h y d ro g e n p e r pound o f f u e l .
'Ey ° [ a m - w+ o06(6)
,255 l b . % / l b . f u e l
■ + =03(8)1»
■
H « 9 (,2 3 6 ) f 1089=1 4 ( „46) (3 2 5 )» 8 0 j
- 2430 B tu /lb . f u e l .
.
-
.
■
t h e r e f o r e ? th e to t& l lo s s » 2450 x 4 .5 g 11,030 B tu /h r .
■
.
----------------------------- -
.
THERMAL OOHDHOTIVITY OF A HEAT EXCHANGER TEST
Surrmary;
' .
''
.1
. ■■
''
In o rd e r t o determ in e th e degree t o w hich th e h e a t exchanger i n th e
■ ■ ■
■
■■ ■■ ' , ■ la b o r a to r y i s fo u le d by r u s t and f o r e ig n ' m a tte r* a t e s t was made on th e
■ ■■ ' ' " .... ’ .
■
■
u n i t and a f o u lin g f a c t o r determ in ed by c a l c u l a t i o n . The d eterm in ed v alu e
,
.
o f f o u lin g f a c t o r was .0019 which in d ic a te s , t h a t th e h e a t exchanger , i s i n
f a i r c o n d itio n .
H .F. M U lllkln q u o tes th e R f as e q u a l t o 0=002 f o r average
tiondsnse^s • and h e a te rs i n th e h e a t t r a n s f e r c h a p te r o f h is
Thermodynamics”
te x t.
Purpose t
'
/
A fo u lin g - f a c to r was d eterm in ed f o r th e h e a t exchanger used i n t h i s
sy stem f o r th e purpose o f c a lc u la tin g th e e f f ic ie n c y o f th e Unite
F ro o e d u re :
Equipm ent was a rra n g e d so t h a t c o ld w a te r was c i r c u l a t e d th ro u g h th e ■
tu b e s and h o t w a te r c i r c u l a t e d around the. outs id e , o f 'tu b e s i n th e exchanges
Tem peratures o f h o t and c o ld .w a te r-e n te rin g -a n d le a v in g th e u n i t were, ta k e n
a t fiv e -m in u te i n t e r v a l s d u rin g th e one hour te s t,p e r io d * .
The amount o f
c o ld .w a te r flo w in g th ro u g h th e system was' m easured by th r e e s.eperate methods,
(w ater fle w -h ie te r, p re s s u re drop a c ro ss a s h a rp edged o rfio e > and by d i*
f e e t l y w eig h in g 'th e w a te r a f t e r - i t had p a sse d th ro u g h th e exchanger)
in
o rd e r, to-check-- th e a c c u ra c y -Of--flow d e te rm in a tio n by th e - f i r s t two methods.
P rec a u tio n s' were ta k e n t o a d ju s t o u ts id e te m p e ra tu re o f th e exchanger t o
room te m p e ra tu re to e lim in a te any lo s s o f h e a t t o th e atm osphere* _
D is c u s sio n o f r e s u l t s :
' C a lc u la tio n s from th e d a ta o b ta in e d .during th e t e s t in d ic a te d a f o u l ­
in g f a c t o r
as b e in g -e q u a l t o .0019 h r . f t 8 F /B tu .
T h is - is f a i r l y aver*,
age f o r a h e a t exchanger , i n good c o n d itio n * A com parison o f th e -w a te r flow as d eterm in ed by th e th r e e methods, in *
d ip a te s an e r r o r o f 6.8% on th e low s id e f o r c a lc u la te d v a lu e when meas­
u r in g a c ro ss th e o r f i e e . An e r r o r o f 5.6% on th e low s id e was re c o rd e d when
- .
■;
u s in g th e w a te r m eter* These v alu es have been used i n a d ju s tin g e a lc u la *
'
tio n s i n th e b o i l e r t e s t *
/
/
64
SvufPLE TEST DATA
c o ld w ater
c irc u it
h o t w a ter
c irc u it
m eter
c u ft •
o r f ic e
flow
"H2O"
weigh
s c a le
lb s .
in
out
tim e
in
out
83
69
2 :4 0
39
72
4524
3.2
238
83
69
2:48
39
73
4572
3 .3
590
84
70
2 :5 5
39
73
4627
5 .3
900
34
71
3 :05
39
73
4685
3.2
245
84
70
3:10
39
73
4737
3 .2
560
84
70
3:20
39
73
4793
3 .3
900
84
70
3:31
39
73
4862
3 .2
238
84
70
3:39
39
73
4915
3 .3
560
84
70
3 :47
39
73
4971
3.2
900
M a te ria l o f h e a t exchanger tu b e s - - - - - s t e e l ,
10 pass
tu b e s iz e —- s/8 " o .d .
L e n g t h ------- 60"
K s t e e l ------26
q
_______ __,61
l / 2 ii»d«
.d .
T o ta l No. o f t u b e s ---- — 50
O rfice ....................... ........... 877" Di am.
Room te m o e ratu re ----- — 7S0F
55
CALCULATIONS
f o 800 B t u / h r / f t 2/ 0F and i s a te rm for. s u rfa c e h e a t - t r a n s f e r c o e f f i c i e n t
o r eonductanee*
,
T o ta l tim e o f th e run' was 52. m inutes <.
Hot w a te r ——
avg, i n l e t
8S«5F
avge o u t l e t
70o0F
C o ld .w ater • » ■ » » * i n l e t
SOoOF
avg« o u t l e t
TSoOF
S u rfad e a re a o f tu b e s i n , f t 8 g ITDLN
144
D g. o u ts id e d ia m e ter o f t u b e s • i n ■in c h es
L = le n g th o f tubes' i n in ch es
N ® number o f tu b e s
A g a re a in ft* ,
A s X o 6 2 5 ) ( 6 0 ) (50)
g 49°9 f t 8
'
'
W e i^ it o f c o o lin g W a te r/h r a « 1979 x 60 - 2330 Ib /h r ?
LMTD 2. ©i » Og •
Jj Oge m ' "
'
:
TgiL '
. ;
. : .. , .- , ' '
- :'
' -
/ -
s temp d if f e r e n c e b e tire en h o t and c o ld f l u i d a t one end ©f h e a t 0&* i ■,
changer,» Fo '
. ,
©2 & temp d if f e r e n c e betw een ,hot and' c o ld f lu i d s a t o th e r en d ,of th e h e a t
e x c h a n g e rD Fo
LMTD ° 4 4 .5
S.O s 16o4
Io g 9. SoO
44 o5
,
■
■
H eat t r a n s f e r r e d i n th e exchanger i s ;
Q o W Cp
.
...
.
' '
Z
56,
w : 2830
,
: -6p£ 1*0 ■ • ■’ .
;1
.
• &bs- 34d0F (c o ld o u t l e t - —c o ld In le ti)'
, .
th e r e f o r e Q s (2B5Q)( l . 0 ) (W ) a 79,300 B tu /h r*
Ih e e q u a tio n f o r o v e r a ll h e a t t r a n s f e r , i s :
.
. ...
...
Q - UA(LMTD)
where U= o v e r a ll h e a t t r a n s f e r c o e f f i c i e n t i n B t u / l b / h r / 0Fc
A = to t a l a re a i n f t 2 0
^
Q s h e a t t r a n s f e r r e d B tu /h r* .
th e r e f o r e U ® ,■ ,Q-... ; =
76.300
s 1260 B t u / l b / h r / 0F=
A(LIiTD)
(40*9) (1 5 .4 )
.
■■
■
•.
'
-
'
The e q u a tio n f o r o v e r a ll c o e f f i c i e n t o f he,at t r a n s f e r i s :
Hg
I
< r < r ^ E f
. . . . . .
.
w here f g s u rfa c e c o e f f i c i e n t o f h e a t t r a n s f e r *
S 800 B t u / h r / f t 2/ F 0
L = th ic k n e s s i n f t*
K g th e r m a l.c o n d u c ti v ity ,p 26. B tu . , f o r , s t e e l
. .. h F T E ^ j V ’■
% s th e f o u li n g o r s c a le r e s is ta n c e h r f t ? F/fetu*
U s in g 'th e e q u a tio n ' f o r o v e r a ll c o e f f i c i e n t o f h e a t t r a n s f e r :
1260 -
-I ' ■ . •
1260 =
I+
I + ,0625 + R*
BOO 800 (1 2 )(2 6 )
’[' v ' - ;
R f g cQ019 h r * ft*' F/fetu
Flow as m easured ao ro ss orfio© i n p a id w a t e r - l i n e ;
Average p re s s u re drop
------- -—
O r f io e C e e f f i o i e u t
S 0S14 MgO
Q061
D ia in e te r
Q g O A ./iiT "
Q : (.6 1 ) firC 0 8 ? ? )1 /(2 ). 932 p2) ( 5 »2^
[ I T I M T JV
,Ill" /
2 ( *6i) («00418) (4»15) s «,0106 f t S/ s e e .
w o ig h t/h r © <,0106(5600) ($ 8 .4 ) • 2400 .1p/hr„
A etual w e ig h t as m easured g 2648 I b / h r »
O rfic e e r r o r :
2648 - 2460 = 608%
Flow as m easured b y m e te r:
? 2 4 9 7 ol - 452*4 g 44*7 f t ^ / 6 7 m inutes
W s 4 4 .7 /6 0 j (62, =,4) = 2500 I b / h r .
th e r e f o r e 3 m eter e r r o r i s t
68
I
59
. CHAPTER V
SPLIT SYSTEM OF WARM AIR' PAHEL HEATHO
I n tr o d u e ti o n :
I n o rd e r t o approach s a t i s f a c t o r y c o n tr o l o f com fort i n a R ad ian t
h e a te d home i t i s n e c e s s a ry t h a t th e uThermal I n e r t i a " o r l a g o f th e house
he p r a c t i c a l l y th e same as th e "Thermal I n t e r t i a tl o f th e h e a te d p a n e l.
It
has been shown i n p re v io u s C hapters t h a t r a d ia n t h e a tin g w ith h o t w ater
c o i l s p la c e d i n c o n c re te f lo o r s p r e s e n ts a trem endous " la g " problem f o r th e
system t o overcom e,
■' T h is ' c h a p te r p re s e n ts a " s p l i t System o f Warm A ir P an el H e a tin g " ,
This System makes use o f l i g h t e r c o n s tr u c tio n i n f lo o r p a n e ls w ith oonsep
q u e n tia l r e d u c tio n o f la g i n th e sy ste m ,
. The s p l i t system i s a method o f h e a tin g i n w hich warm a i r i s c ir c u s
I a t e d i n th e h o llow c o re s or s l a b s , th e r e b y warming th e f l o o r s u r f a c e , and
th e warm a i r i s th e n d is c h a rg e d i n t o th e room th ro u g h c o n tin u o u s b aseb o ard
r e g i s t e r s T h e warm s la b forifis th e " r a d ia n t h e a tin g " s u r f a c e .
A d d itio n a l
h e a t and r a p id c o n tr o l a re o b ta in e d b y d is c h a rg in g th e a i r i n t o th e room
th ro u g h r e g i s t e r s a f t e r i t has warmed t h e s l a b .
The warm a i r se rv e s, a ls o
t o warm e x t e r i o r w a lls and windows and th e r e f o r e re d u c es t h i s so u rces o f
down d r a f t and d isc o m fo rt,.
The s p l i t system d e s ig n :
Layout i s sim ple because an extended-plenum ty p e o f su p p ly and r e t u r n
duct i s u sed .
This means t h a t a l l th e d u c ts a re o f c o n s ta n t s iz e th ro u g h ­
o u t t h e i r e n t i r e l e n g th .
These ex ten d ed plenum su p p ly d ticts a re n e c e s sa ry
because th e y fe e d a la rg e , number o f c lo se ly « s p a c e d c o n s ta n t- s iz e h o le s t h a t
,c a r r y 't h e a i r th ro u g h th e s l a b s .
Q u a n tity o f a i r flo w in g in . any p a r t i c u l a r
room depends upon th e number o f a v a ila b le co res and on s e t t i n g o f a v a ri=
a b le opening s l i d i n g damper i n th e b a se b o a rd r e g i s t e r s .
Because th e f I o p t i s e v e n ly h e a te d i t i s n o t n e c e s s a ry t o i n s t a l l r e ­
t u r n a i r r e g i s t e r s i n th e o u ts id e w a lls o f each room.
Most i n s t a l l a t i o n s . u
r e q u ir e o n ly one r e t u r n - a i r in ta k e lo c a te d in* a, c e n tr a l h a l l t h a t has. ,free
a i r p assag e t o a l l rooms su rro u n d in g i t .
The warm a i r r i s i n g from th e w a lk
te n d s t o c o u n te r a c t d o w n -d rafts t h a t e x i s t - WfiiIe th e warm f l o o r . im p arts a
buoyancy e f f e c t t o t h e r e t u r n a i r and .p re v e n ts' c o ld d ra fts " from flo w in g a<=
lo n g th e f l o o r V
Tn la r g e ram b lin g b u ild in g s , more th a n ,. one re tu r n , a ir. d u c t
amy be n e c e s s a ry t o p re v e n t a. s in g le r e t u r n from becoming to o la rg e to : be
p r a c t i c a l , . ■-
t
,Two b a s ic ty p e s o f warm a i r d u ct la y o u ts can be c o n s id e re d , th e Cen­
t r a l ; d u c t system and th e double d u c t system w ith an a l t e r n a t e method c a ll e d
the, r e v e rs e d double: d u e t system ,: •
.
The s im p le s t i s th e c e n t r a l d u c t sy stem whereby one s u p p ly d u et i s usd
t o su p p ly a l l a i r a v a ila b le w ith c o re s ru n n in g l a t e r a l l y i n b o th d ir e c tio n s
from th e supply;,
room s.
This system re q u ir e s a c e n t r a l h allw ay t h a t a d jo in s a l l
Rooms re m o te ly lo c a te d w i l l n o t r e c e iv e th e b e n e f i t o f the i n i t i a l
h e a t lo s s and must be s u p p lie d by a s e p a ra te duct.;
i n F ig u re 21«,
This ty p e i s illustrated
■<
When i t i s d e s ir e d t o c o n t r o l th e h e a t t o one room in d ep en d en t o f th e
o th e rs # th e r e v e rs e d double d u c t system may be u sed ,
An a i r 's e a l p re v e n ts
th e a i r from c o n tin u in g t o an opposite, r e g i s t e r - and: tu r n s th e a i r 40 t h a t
i t flow s back t o a b aseb o ard r e g i s t e r i n th e same room .
Q th erM se i t r e -
61
SUWY
Central Duct System
F ig u re 21
- •>
62
se mbI e s th e double d u c t systepio
•'
‘ \
'
M S 1 6 » WGfiBSTiOKS
'
Bampers sh o u ld be' i n s t a l l e d i n each su p p ly duct le a v in g ,th e fu rn ac e
bonnet s o t h a t th e system may be b a la n c e d as neededo
i n la r g e system s w ith
zone c o n t r o l » m o to rize d dampers may be i n s t a l l e d t o m odulate Or s h u t o f f
c e r ta in s e c tio n s »
'
,
S inds th e s la b s lo s e h e a t i n b o th d ir e c tio n s i t .may be n e c e s sa ry t o
i n s u l a t e th e bottom o f th e s la b s i f p la c e d over an u h h e ate d e’r aw l space o r
i r a c a r p e t i s t o be used on th e f l o o r o
I f th e space-below i s v e n t i l a t e d ,
i t may be n e c e s s a ry t o p ro v id e a d d itio n a l in s u l a t i o n i n th e form o f ' I -inch,
i n s u l a t i n g b o ard Or 2- in c h b la n k e t in s u la tio n ^
A nother so u rce o f lo s s i s around th e exposed p e rim e te r o f th e f l o o r .
S ince th e f l o o r i s c o n c re te and i s c o n n e c te d t o an u n in s u la te d co n crete
fo u n d a tio n , th e exposed edge sh o u ld be p r o te c te d by 1 -in e h ! in s u la tio n b o ard
around th e p e rim e te r o f th e co red f l o o r .
The to p b lo c k o f t h e fo u n d a tio n
w a ll sh o u ld p r e f e r a b ly be f i l l e d W ith lo o se i n s u l a t i o n .
The ends o f th e
c o re s may be s tu f f e d w ith a t h i c k b a l l o f i n s u l a t i o n .
C o n tro ls f o r t h i s sy stem a re s e t i n th e same manner as i n a convene
t i o n a l Warm=Bir System 0
maximum.
The bonnet l i m i t sw itc h sh o u ld b e s e t a t 200°F
The f a n sw itc h sh o u ld be s e t a t th e lo w est p o s s ib le te m p e ratu re
t o in s u re p ro lo n g e d blow er o p e r a tio n .
95*95° f a n s w itc h c u t- o u t p o i n t .
This te m p e ra tu re i s u s u a lly about
Fan sp eed should be a d ju s te d u n t i l a i r
te m p e ra tu re a t th e b onnet i s a p p ro x im a te ly 140°F Under c o n tin u o u s O peration0
Any ty p e o f th e rm o s ta t may be u sed f o r t h i s system as th e d isad v a n ta g e
o f " e x c e s s iv e th e rm a l la g " in h e r e n t t o r a d i a n t h e a t system i s reduced t o a
65
minimum, i n a System of t h i s type*
DBSiaIr PROCEDURE
,
■Determining h e a t lo s s $
™
" ‘ '
r ""
--
r
' ' ' 1 ' ,l
The s p l i t system o f p an el h e a tin g a ch ie v e s f i n a l c o n tr o l and b a lan c e •
a t th e su p p ly g r i l l e u n i t s .
This s im p lif ie s th e h e a t lo s s c a lc u la tio n s
f o r omall:# s in g le s t o r y i n s t a l l a t i o n s i n t h a t o n ly o v e r a ll h e a t lo s s i s a l l
t h a t i s u s u a lly re q u ire d =
I f a room has e x c e s s iv e g la s s s u r f a c e » th e h e a t
lo s s e s sh o u ld be c a lc u la te d in , th e u su a l m anner; how ever, th e -fo llo w in g
eq u atio n , may be u sed fo r. e s tim a tio n o f . o v e r a l l h e a t lo s s *
I t is an eq u a­
t i o n q u o te d from th e Guide o f th e A n erican S o c ie ty of S e a tin g and V e n tilac­
t i n g E n g in e e rs .
I t i s a p p lic a b le t o d e ta c h e d ■houses a p p ro x im a te ly r e c ta n ­
gular. i n Shape. Iiaving a door and window a r e a eq u al t o ab o u t 25% of th e flo o r
a r e a , and w ith a f l o o r arfea n o t g r e a te r th a n a b o u t 1500 S g . f t .
For a one s t o r y r e s id e n c e :
H1 = (G + Bw + Uc) x (70 o tq ) x A
where =
H1 - i s t o t a l h e a t lo s s e x c lu d in g basem ent o r f l o o r l o s s .
■■
..
v ' '
..
A g. f l o o r a r e a , sq u are f e e t (e x c lu d in g 'b a se m e n t) .
G o g la s s and I n f i l t r a t i o n f a c t o r for- o rd in a ry c o n s tru c tio n *
0*45 f d r no w e a th e r s tr ip o r storm g la s s
OAO f o r w e a th e r s tr ip .
0 .3 0 f o r sto rm g la s s w ith o r w ith o u t w e a th e rs trip p in g *
Uw - o v e r a ll c o e f f i c i e n t Of tra n s m is s io n Of o u tsid e , w a ll.
U0 = o v e r a ll c o e f f i c i e n t f o r c e i l i n g ;
t 0 - o u ts id e d e s ig n te m p e ra tu re (v a r ie s w ith l o c a l i t y ) .
I n o rd e r t o a cc o u n t f o r r e v e rs e lo s s th ro u g h th e s la b a q u a n tity o f
■-
64'
B tu e q u a l t o IG tim e s th e f l o o r a re a i s u s u a lly added, t o e s tim a te d h e a t
" lo s s e s a b o v e ,„
B e te rm in a tio h o f fu rn a c e s i z e :
Bonnet o u tp u t i s th e ty p e o f fu rn a c e r a t i n g t h a t i s m ost commonly used
a t th e p resen t" tim e .
I t i s th e amount o f h e a t t h a t th e fu rn a c e w i l l d e liv e r
a t th e b o n n e t» e x p re ss e d i n term s o f B tu p e r h o u r.
O utput a t th e "bonnet.
e q u a ls th e in p u t o f .th e fu rn ac e m u ltip lie d b y th e o v e r a ll .e f f ic ie n c y .
In
th e ease o f gas furnaces i t i s common p r a c tic e to c o n sid e r th e .o v e ra ll .e f ^ .
f ie ie n c y as 80%.
Heat i s l o s t on th e way from th e fu rn a c e t o th e f l o o r s la b s .-
S tan d ard
" y■
'
p r a c tic e w ith in th e Warm A ir B ea tin g I n d u s tr y i s . t o assume th e " p ip in g , lo s s
a s 15% f o r " w in te r a i r c o n d itio n in g " system *
Ih e o u tp u t t o th e s la b s would
th e r e f o r e be 85% o f th e B onnet o u tp u t.
I f th e fu rn a c e i s a u to m a tic a lly f i r e d w ith - g a s , o i l „ o r a s to k e r , th e
c o r r e c t fu rn a c e s iz e i s one t h a t c au se s th e b u rn e r t o ru n c o n s ta n tly i n th e
c o ld e s t w e ath e r you w i l l e v e r h a v e », I f u n au to m atic fu rn a c e i s o v e rsiz e d
i t i s d i f f i c u l t t o c o n tr o l for^maximum c o m fo rt,
! a b l e 'I I s hows ' a".convenient s i z i n g t a b l e f o r t o t a l c a lc u la te d le s s
v e rs u s minimum fu rn a c e bonnet c a p a c i t i e s 0 ta k in g in to c o n s id e ra tio n , th e 15%
duct; lo s s a s '.■s u g g e s te d above*
’D e te rm in a tio n ' o f b l ower s i z e «
'’ '
..............................'
Table I l -shows a l i s t i n g - of1-' p ro p e r blow er s iz e s t o be Used I n the- s p lit
...
_
system d e s ig n u s in g vBlI e x ic o r e ir hollow c o n c re te s la b s *' .Blower s iz e s l i s t e d
a re ta k e n from th e lfF leX ieo re D esign Manual" p u t o u t b y th e F ex ico re Gompaay
Dayton,. O hio,
Blower -s iz e s a r e a ls o a p p lic a b le when u s in g o th e r ty p e s o f
65
T otal C alo•
lo s s
Min. furnace
Beq. blower
bonnet oap.
ca p a city
B tu /h r •
B tu /h r.
Cfa
30,000
36,000
470
40,000
47,000
630
60,000
69,000
790
60,000
71,000
960
70,000
82 ,000
1090
80,000
94,000
1260
90,000
106,000
1410
100,000
118 ,000
1670
110,000
129,000
1730
120,000
141,000
1890
130,000
163 ,000
2040
140,000
166,000
2200
160,000
177,000
2350
Table 11
hollow f l o o r c o n s tr u c tio n as h iew er speed may be a d ju s te d f o r s a t i s f a c t o r y
re s u lts 6
Ratings.- hown i n th e t a b l e are b ased upon d e liv e r y o f r a t e d q u a n titie s
o f a i r ’ a t -p«20 in ch es w a te r gage s t a t i c p re s s u re e x te r n a l t o th e u n i t ,
'
'v
'
.
R a tin g s a re f u r t h e r b ased on 140° a t th e b o n n et when o p e ra tin g c o n tin u o u s ly
d u rin g d e s ig n w e a th e r c o n d itio n s ,
Cfm re q u ire m e n ts i may a ls o be c a lc u la te d from th e B tu h e a t lo s s 6 The
fo llo w in g fo rm u la ta k e n fro m "Warm J lir H eatin g " b y I o r r i s may. be used f o r
c a l c u l a t i n g p ro p e r blow er s i z e .
'B onnet.
The B tu f ig u r e used must be B tu a t th e
TR e q u a ls te m p e ra tu re r i s e th ro u g h th e f u r n a c e o
o f m g B tu x 55
60 x TR "
,
Tem perature r i s e th ro u g h th e fu rn a c e sh o u ld i n a n y .c a se be h e ld w ith in
th e l i m i t s o f 85° t o IOCb when h e a tin g th e house i n th e c o ld e s t w e a th e rp
D e te rm in a tio n o f su p p ly and r e t u r n a i r d u c t s :
The two c h a r ts * shown i n f ig u r e s 23 and 24 p re s e n t a q u ic k method o f
d e te rm in in g th e r e q u ir e d w id th o f e i t h e r a 6 -in c h or an 8 " in c h d e p th d u ct
b ased upon th e q u a n tity o f a i r t o be h an d led and th e f u r t h e s t d is ta n c e th e
a i r m ust t r a v e l .
They in c lu d e an. e s tim a te f o r r e s is ta n c e o f elbows and
o th e r f i t t i n g s .
For s i m p l i c i t y , th e m easure le n g th i s d iv id e d in to two
c a te g o r ie s i . e . , 10 t o 50 f e e t and 50 t o 100 f e e t ,
The r@turn=»air c h a r t assumes t h a t each r e t u r n d u ct i s co n tin u o u s from
each r e tu r n = a ir g r i l l e t o th e r e t u r n plenum on th e fu rn a c e and .th a t th e
g r i l l e s w i l l be lo c a te d somewhat c e n t r a l l y i n th e b u ild in g .
*FLBXIGORB T e ch n ical D ata Handbook, S e c tio n 5 , C h ap ter 3.- P ublish=
ed by F le x ic o re M anufacturer *s ,A sso c ia tio n , In e .-, D ayton, Ohio*
67
Ex a m p l e of D uct L a t o u t s a n d D f f e c t
of F u r n a c e L ocation on Duct S izes
/y ''
A
o
Fl o o r A
U WALL
( J ceiling
G
= IBoo
rea
s q
. ft .
= O . I5
= 0 . 12
= O. 3 0
H = ACc-KUw+Uc) At +(io-A)
= I5 0 0 ( o . 3 0 + 0 . 1 5+ 0.12) S o + ( l O * I B O O )
=
+5.5
X IS o o
+-IOX 1 5 0 0
=• 5 5 . 5 X I S o o = 5 3 , 0 0 0 3 T U / N a .
M i n i m u m B o n n e t C a p a c i t y - cTS1C o o
C F M= 1300
-
■/■/•
B -2
su re d
C F M / D U C T MLea
ength
<
A -2
A -3
F u r n a c e at o n e e n d
Fu r n a c e in m i d d l e
Fu d n a c e
6-1 F u r n a c e
b '2
Furn a ce
1300
650
. 325
d ista n c e
at o n e
IoSO
end
D
in
m id d le
u cts
Duc t s
Figure 22
" x"- C b o
'y-325
as'
4 -0'
30’
55"
95'
O o
S v s t e m
D u lt S ize
47-6’or31“x821"x6“O
RIS"*8'
12"*6" or 6 x8"
AND
.
36x 6"o r 24- 6
25 *6 oR ITx8*
25"x6' O
R nu
x8"
13 ott |c/x8
S*
.
-
.
-
TaWo I I I * i s a r o t u r n - a i r g rill© s i a i n g ta b le and i s b ased upon a .■■
maximum g r i l l e v e l o c i t y because o f n o ise and way .pressure d r o p .. Any o f 'th e
la r g e r s ia e s th a n th o s e r e q u ir e d i s J u s t ** a c c e p ta b le <,
*FLEX100Rli; T ec h n ica l D ata Handbook, S e c tio n Sp Chapter 3 . ' Published
by Flexioor© M an u factu rer6s A s s o c ia tio n , I n o , , Dayton, O hio,
69
SUPPLY
DUCT
BASED
D U C T
D E P T H
6,
SIZING
CHART
U P O N
M E A S U R E D
LENGTH
WIDTH
OF
RECT.
DVCT
-
INCHES
O /00
zoo
IZoo
4-00
C PM
IN
Figure 23
SUPPLY
DUCT
70
r e t u r n
SIZING
d u c t
BASED
c h a r t
UPON
w
IOTH
OF
RECT.
DUCT- SHCH E S
DU C T - D E P T H
fooo
CFM
IN RETURN
Figure 24
J
71
RETURN-AIR GRILLE SIZING TABLE
CFM
Nominal G r ille Size —*- 'i nches
FREE AREA
sq . in .
10
12
14
16
18
20
22
24
28
30
36
8
8
6
5
6
5
4
4
4
4
4
10
10
8
8
6
6
6
6
5
4
200
58
300
87
400
115
12
10
10
8
8
8
6
6
5
500
144
14
12
12
10
10
10
8
8
6
600
173
16
14
12
12
10
10
8
8
700
202
16
14
14
12
10
10
8
800
230
18
16
16
14
12
12
10
900
259
18
16
16
14
12
10
1000
288
18
18
14
14
12
1100
317
22
18
16
16
14
1200
345
20
18
16
14
1300
375
22
18
13
16
1400
404
22
20
18
16
TABLE I I I
72
LITBR ATDRE CONSULTED
Adlam1 3M5T.
,RADIANT HEATING, , 1949
Amsrioan S o o is iy o f H e a tin g and V e n tila tin g E ngineers G u id e, .1 9 5 2 , 1953
B e ll and G o sse tt Company, Company L i te r a tu r e
Chase B rass and Copper,Company, SUGGESTIONS FOR DESIGNING RADIANT PANEL
HEATING WITH COPPER TUBING,
1943
D e tr o it L u b rio a to r Company, Company L i t e r a t u r e
' F le x lo o re Company, Company L i te r a tu r e
Foxbofo Company^ Company L i te r a tu r e
H eatin g and V e n tila tin g Mag0e J u ly 1954
Jen n in g s and Lewis', AIR CONDITIONING ' MD REFRIG,)' 1946
K ent, MECH., ENGReS HANDBOOKS, e le v e n th e d .
M inneapolis "Honeywell R e g u la to r Company, Company. L i t e r a t u r e
M arks, MECH« ENGR9S HANDBOOK, f o u r th e d i t i o n
M u llik in , H .F ,, THERMODYNAMICS
N p r r is , WARM AIR HEATING AND WINTER AIR CONDITIONING, 1948
Penn C o n tr o ls , I n o ® Company L i te r a tu r e
Severns and D e g le r, STEAM AIR AND GAS PONER, 1946
Shoemaker, RADIANT HEATING, 1948
/
,
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N378
J636d
co p . 2.
114817
Jo h n so n , R. A.
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