Home heating using a wood-fired boiler in conjunction with a heat storage unit
by Steven Richard Hagan
A thesis submitted in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE
in Industrial Arts Education
Montana State University
© Copyright by Steven Richard Hagan (1978)
Abstract:
The purpose of the study was the design, construction and operation of a wood-fired boiler, used in
conjunction with a heat storage unit,to heat a single-family dwelling.
The system consisted of a fire tube type boiler to heat water that was stored in a 1500 gallon storage
tank. This hot water was used to heat the house through fin tube type radiators mounted under the floor
joists of the main floor of the house. The system was installed and tested in a house located near
Bozeman, Montana.
In order to evaluate the performance of the system, two variables were studied. One was the amount of
potential energy available in the fuel and the second variable was the amount of heat that was actually
realized in the house.
To compare the wood heating system's performance with a conventional heating system, electrical
baseboard heaters were used as a control. The two systems were operated alternating weekly, with the
wood heating system in operation for three weeks and the electrical heating system operating for two
weeks.
Measurements of the temperature both inside and outside the house were taken every hour using two
thermographs. This temperature difference was used to calculate the heat needed to keep the house at a
comfortable temperature. The wood that was consumed in the boiler was weighed to determine the
potential energy available and a watt hour meter was installed on the electrical heating system to record
the amount of electricity used.
It was found that the wood heating system provided heat for $1.75 per million Btu1s and the electrical
heating system provided heat for $5.89 per million Btu's. The wood-fired boiler operated at an
efficiency of 55 percent. STATEMENT OF PERMISSION TO COPY
In p re s e n tin g t h i s t h e s is in p a r t i a l f u l f il l m e n t of
t h e r e q u i r e m e n t s f o r an a d v a n c e d d e g r e e a t M ontana S t a t e
U n i v e r s i t y , I a g r e e t h a t t h e L i b r a r y s h a l l make i t f r e e l y
a v a ila b le fo r in sp e c tio n .
I f u r t h e r ag ree t h a t p e rm iss io n
f o r e x t e n s i v e c o p y in g o f t h i s t h e s i s f o r s c h o l a r l y p u r ­
p o s e s may b e g r a n t e d by my m a jo r p r o f e s s o r , o r , i n h i s
ab sen ce, by th e D ir e c to r of L i b r a r i e s .
I t i s u n d e rsto o d
t h a t any c o p y in g o r p u b l i c a t i o n o f t h i s t h e s i s f o r f i n a n ­
c i a l g a i n s h a l l n o t b e a ll o w e d w i t h o u t my w r i t t e n p e r m i s s i o n
S ig n a t
D a te
HOME HEATING USING A WOOD-FIRED BOILER IN CONJUNCTION
WITH A HEAT STORAGE UNIT
Uy
STEVEN RICHARD HAGAN
A t h e s i s su b m itte d i n 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 ire m e n ts f o r th e d eg ree
of
MASTlLR OF SCIENCE
I n d u s t r i a l A r ts E d u c a tio n
A p p ro v e d :
C h a i r p e r s o n , 'G r a d u a t e C om m ittee
YlTU-I- ^
H ead, M a jo r D e p a r tm e n t
G r a d u a i eCLDe an
MONTANA STATE UNIVERSITY
Bozeman, M ontana
J u n e , 1978
4
i.ii
t
ACKNOWLEDGMENTS
The w r i t e r w i s h e s t o e x p r e s s h i s s i n c e r e a p p r e c i a t i o n
t o t h e p e r s o n s w hose a s s i s t a n c e c o n t r i b u t e d t o t h i s s t u d y : .
To Dr . Doug P o l e t t e , whose t e c h n i c a l a d v i c e and phys^i c a l c o n t r i b u t i o n t o t h e p r o j e c t was i n v a l u a b l e .
To D r. Max A m berson, t o r h i s a i d e a n d e n c o u r a g e m e n t .
a s t h e w r i t e r ' s c o m m itte e c h a i r m a n .
To D r . Doug B i s h o p , t o r h i s a d v i c e a n d h e l p a s a member
o f t h e w r i t e r ' s c o m m i tt e e .
To t h e D e p a r tm e n t o f A g r i c u l t u r a l and I n d u s t r i a l E d u c a ­
t i o n , M ontana S t a t e U n i v e r s i t y , f o r t h e g r a d u a t e a s s i s t a n t s h i p t h a t made a d v a n c e d s t u d y p o s s i b l e .
To Don L e e , f o r t e c h n i c a l a d v i c e and I i i s a p p l i c a t i o n
o f g r e a t . e x p e r t i s e in w e ld in g .
To L u e l i a P o l e t t e , f o r h e r t o l e r a n c e and h o s p i t a l i t y
d u rin g th e p r o j e c t .
.
To N o e l l e , f o r h e r c o n s t a n t s u p p o r t and t h e e f f o r t and
e n t h u s i a s m i n e d i t i n g and t y p i n g .
TABLE OF CONTENTS
VITA e e o e e e
ACKNOWLEDGMENTS
LIST OF TABLES .
LIST OF FIGURES
ABSTRACT . . . .
CHAPTER I :
e e e o e e e e e e o e o e e w e e e e
H
.................................. ............................................... . . i i i
. . . .
...........................................
vi
. .............................
f . . i . . v ii
. . . . . . . . . . . . . . . . . . .
.v iii
THE PROBLEM AND ITS S E T T I N G ..................................
I n t r o d u c t i o n ......................................
S t a t e m e n t o f t h e P ro b le m ......................................
Need f o r t h e S tu d y . . . . . . . . . . . . . . .
O b je c tiv e s . . . . .
......................... . . . . . . . .
A s s u m p t i o n s ........................
L im ita tio n s
. . .
......................... . . . . . . . . .
D e f i n i t i o n o f T erm s
. . . . . . .
.................... . .
P rocedure
.......................... 1 . . . . . . . . .
CHAPTER I I :
I
I
2
2
4
4
5
6
7
. . .
. . .
. . .
. . .
.
.
REVIEW OF LITERATURE AND RELATED RESEARCH .
Wood a s F u e l ...................................................................
F uelw ood C o s t s v s . C o n v e n t i o n a l E n e rg y S o u r c e s . .
. F u e lw o o d P r o p e r t i e s
. . . . . . . . . . . . . . .
B o i l e r and H e a t S t o r a g e U n i t D e s ig n
. . . . . . .
B u i l d i n g H e a t L o s s ................................................
H eat S to ra g e U n it
. . . . . . . . . . . . . . . . .
B o i l e r H e a t A b s o r p t i o n A r e a ............................
IO
10
13
16
18
18
23
23
. .
. .
. .
. .
i
CHAPTER I I I :
SYSTEM DESIGN
.............................. . . . . . . .
B u i l d i n g H e a t L o s s .............................................................................
H eat S to ra g e U n it
..........................................................
B o i l e r ...................................................................................
H eat C i r c u l a t i o n and D i s t r i b u t i o n
26
.
26
30
31
36
.
42
In tro d u c tio n . . . . . . . . . . . . . . . . . . . . .
B u ild in g H eat L oss C a lc u la tio n . . . . . . . . . . . .
E n e rg y Use C a l c u l a t i o n . ....................................... .... . . . . .
B o ile r E ffic ie n c y
.............................
42
42
.46
48
CHAPTER IV:
PRESENTATION OF DATA
. . . . .
7 . . . .
A
:V
Wood v s . E l e c t r i c i t y :
C o n c lu sio n
CHAPTER V:
C o s t A n n l y s i s .............................
^
50
I ^ 53
CONCLUSIONS, IMPLICATIONS AND
RECOMMENDATIONS FOR FURTHER STUDY . . . . . .
55
.
C o n c l u s i o n s ............................. . . . . . .
. .5 5
Im p lic a tio n s . . . . . . . . . . . .
. . . . . . . . .5 5
R e c o m m e n d a tio n s f o r F u r t h e r S tu d y . . . . . . . . . . .
56
APPENDIX ........................................................... i . . . . . . . . . .
BIBLIOGRAPHY . . . . . . . . . . . . . . . . . . . . . .
58
64
I:
O
vi
LIST OF TABLES
T ab le
P age
1
NATURAL GAS PRICE SCHEDULE ...........................................
. .
2
ELECTRICITY PRICE SCHEDULE . , . . . . . . . . .
.
3
COMPARATIVE PRICES OF SELECTED FUELS . . . . . . .
16
4
POTENTIAL ENERGY OF VARIOUS WOOD SPECIES . . . .
17
5
HEAT LOSS COEFFICIENTS OF VARIOUS BUILDING
M A T E R IA L S ........................ .... . . .
. . . . .........................
20
6
OUTDOOR DESIGN TEMPERATURE .
21
7
SQUARE FOOTAGE OF BUILDING SYSTEMS IN TItE HOUSE
8
TOTAL HEAT LOSS IN BTU PER HOUR BY TRANSMISSION
AND INFILTRATION........................ ............................ ....
28'
AREA OF HEAT ABSORPTION IN THE BOILER
34
9
10
. . ...
. . .
. . .
.
. . . .
14
15 ""
27 ■"
DAILY AVERAGE TEMPERATURE DIFFERENCE AND HEAT LOSS
IN GROUND FLOOR OF HOUSE . . . . . . . . . . . . .
44
TOTAL HEAT LOSS PER WEEK, HOUSE AND FLOOR OR
BASEMENT................................................................ . .
46
12
TOTAL HEAT LOSS VERSUS ENERGY USED . . .
47
13
EFFICIENCY IN PERCENT OF THE WOOD-FIRED BOILER
14
ENERGY SOURCE USE AND WOOD VS. ELECTRIC COST
COMPARISON........................ .... .................................. ....
51
SCHEDULE FOR CALCULATING COST OF ELECTRICITY USED
52
11
15
....................
. .
4f)
I;
A
r-
v ii
JJST OF FIGURES
F ig u r e
P ase
1
FIRE TUBE B O IL E R ................................................
2
HEATING SYSTEM SCHEMATIC . . . . . . . . . . . .
37
3
TEMPERATURE GRAPH IpOR MARCH 20 - 21
. . . . . .
59
4
TEMPERATURE GRAPH FOR MARCH 2 7 - 3 . 1
. , . . . .
GO
5
TEMPERATURE GRAPH FOR APRIL 3 - 7
. . . . . .
61
6
TEMPERATURE
GRAPH FOR APRIL LO - 14
. . . . . .
62
7
TEMPERATURE GRAPH FOR APRIL 16 - 20
. . . . . .
63
.
. . . i .
35
v lii
ABSTRACT
The p u r p o s e o f . th e s t u d y was t h e d e s i g n , c o n s t r u c t i o n
and o p e r a t i o n o f a w o o d - f ir e d b o i l e r , u se d i n c o n ju n c tio n
w ith a h e a t s to ra g e u n i t , t o h e a t a s in g le - f a m ily d w e llin g .
The s y s te m c o n s i s t e d o f a f i r e t u b e t y p e b o i l g r t o h e a t
w a t e r t h a t was s t o r e d i n a 1500 g a l l o n s t o r a g e t a n k . T h i s
h o t w a t e r was u s e d t o h e a t t h e h o u s e t h r o u g h f i n t u b e t y p e
r a d i a t o r s m o u n ted u n d e r t h e f l o o r j o i s t s o f tfie m ain f l o o r
o f t h e h o u s e . The s y s te m was i n s t a l l e d and t e s t e d i n a
h o u s e l o c a t e d n e a r Bozeman, M o n ta n a .
I n o r d e r to e v a lu a te th e p erfo rm an ce o f |h e sy stp m ,
two v a r i a b l e s w e re s t u d i e d .
One was t h e am ount o f p o t e n t i a l
e n e r g y a v a i l a b l e i n t h e f u e l and t h e s e c o n d v a r i a b l e was
t h e amount o f h e a t t h a t was a c t u a l l y r e a l i z e d i n t h e h o u s e .
To com pare t h e wood h e a t i n g s y s t e m 's p e r f o r m a n c e w i t h a co n ­
v e n t i o n a l h e a t i n g s y s te m , e l e c t r i c a l b a s e b o a r d h e a t e r s w ere
u s e d a s a c o n t r o l . The two s y s te m s w e re o p e r a t e d a l t e r n a t ­
i n g w e e k l y , w i t h t h e wood h e a t i n g s y s te m in o p e r a t i o n f o r
t h r e e w eeks and t h e e l e c t r i c a l h e a t i n g s y s te m o p e r a t i n g f o r
two w e e k s .
M e a s u re m e n ts o f t h e t e m p e r a t u r e b o t h i n s i d e and o u t ­
s i d e t h e h o u s e w e re t a k e n e v e r y h o u r u s i n g two t h e r m o g r a p h s .
T h i s t e m p e r a t u r e d i f f e r e n c e was u s e d t o c a l c u f a t e t h e h e a t
n e e d e d t o k e e p t h e h o u s e a t a c o m f o r t a b l e t e m p e r a t u r e . The
wood t h a t was consum ed i n t h e b o i l e r was weighted t o d e t e r ­
m ine t h e p o t e n t i a l e n e r g y a v a i l a b l e and a w a t t h o u r m e te r
was i n s t a l l e d on t h e e l e c t r i c a l h e a t i n g systeiti t o r e c o r d t h e
amount o f e l e c t r i c i t y u s e d .
I t was f o u n d t h a t t h e wood h e a t i n g s y s te m p r o v i d e d h e a t
f o r $ 1 .7 5 p e r m i l l i o n B t u 1s and t h e e l e c t r i c a l h e a t i n g sy s te m
p r o v i d e d h e a t f o r $ 5 .8 9 p e r m i l l i o n B t u ' s .
T}]p w o o d - f i r e d
b o i l e r o p e r a t e d a t an e f f i c i e n c y o f 55 p e r c e n t .
CHAPTER I
THE PROBLEM AND ITS SETTING
INTRODUCTION
P e o p l e a r e b e c o m in g more i n t e r e s t e d i n a l t e r n a t i v e s t o
‘
v
t h e u s e o f c o n v e n t i o n a l h e a t s o u r c e s t o h e a t t h e i r hom es.
They may b e c o n c e r n e d w i t h t h e u s e o f f i n i t e f o s s i l f u e l s
o r , m ore p r o b a b l y , t h e y a r e c o n c e r n e d w i t h f h p i n c r e a s e i n
t h e c o s t o f h e a t i n g t h e i r homes w i t h c o n v e n t i o n a l f u e l s .
It
h a s b e e n f o r e c a s t t h a t b e tw e e n 1972 and 1 9 8 5 , t h e c o s t o f
No. 2 f u e l o i l w i l l i n c r e a s e by 613%, e l e c t r i c i t y by 157%
and t h a t by 1 9 8 1 , n a t u r a l
g a s w i l l i n c r e a s e 409% ,“ . A s . a
r e s u l t , p e o p l e w i l l be l o o k i n g f o r a l t e r n a t e e n e r g y s o u r c e s
o r ways oI' r e d u c i n g c o n v e n t i o n a l e n e r g y c o n s u m p ti o n .
One a l t e r n a t i v e i s t h e u se o f wood;
In many p a r t s o f
t h e c o u n t r y , t h e r e i s am ple wood on a r e n e w a b le b a s i s a n d ,
i f used, w i s e l y ,
t h i s cou.l d . s u p p l y many f a m i l i e s w i t h t h e i r
home h e a t i n g n e e d s .
However', th e p r o b le m s i n v o lv e d i n u s i n g
wood t o h e a t homes have l i m i t e d i t s u s e .
^ Al an I,. .Ilaminoml, " I n d i v i d u a l Se I I - S u T f i c i e n c y
E n e r g y , " Sc ionco 18-1, ( A p r i l 19, I 9 7 4 ) , p. 278.
in
2S t e w a r t Byr.no., R e p o rt / / I ; The A r k a n s a s S f o r y ( T o l e d o ,
Ohio.:
Owens—C o r n in g E L h e rg T a ss C o r p . , ! 9 7 5 ) , p . I .
-2 -
; When u s i n g wood t o h e a t a hom e, a c e r t a i n amount o f '
in c o n v e n ie n c e i s in v o lv e d .
I f a c o n v e n t i o n a l wood s p a c e
h e a t e r i s u s e d , i t m u st b e l o a d e d a number o f t i m e s d u r i n g
t h e day and t h e r a t e o f c o m b u s tio n m u st b e c o n t r o l l e d i n
o r d e r t h a n an e v e n h e a t b e p r o d u c e d .
T h i s c r e a t e s an ad­
d i t i o n a l p r o b le m o f i n c o m p l e t e c o m b u s tio n and t h e p r o d u c ­
t i o n o f l a r g e am o u n ts o f sm oke.
T hese p ro b lem s c r e a t e a
n e e d f o r a c e n t r a l wood h e a t i n g s y s te m t h a t w p u ld be com­
p e t i t i v e w i t h o t h e r a l t e r n a t i v e e n e r g y h e a t i n g s y s te m s and
b u r n wood e f f i c i e n t l y t h u s p r o d u c i n g l e s s smojee arid m i n i ­
m i z i n g homeowner i n c o n v e n i e n c e .
STATEMENT OF rI1HE PROBLEM
The p u r p o s e o f t h i s s t u d y was t o d e s i g n and c o n s t r u c t
a w o o d -fire d b o i l e r to be u se d i n c o n ju n c tio n w ith a h e a t
s to ra g e u n i t to h e a t a s in g le fa m ily d w e llin g .
The f e a s i ­
b i l i t y o f t h e wood h e a t i n g s y s te m was t h e n t o be com pared t o
a c o n v e n t i o n a l e l e c t r i c a l h e a t i n g s y s te m .
NEED FOR THE STUDY
The n e e d f o r a c e n t r a l h e a t i n g sy s te m u s i h g wood a s
th e fu e l i s th r e e f o ld .
F i r s t , w ith th e p ro je c te d in c re a s e
i n t h e c o s t o f c o n v e n t i o n a l e n e r g y s o u r c e s su c h a s e l e c t r i c i t y .
-3 -
n a t u r a l g a s and f u e l o i l , hom eow ners a r e l o o k i n g f o r c h e a p e r
a lte r n a tiv e so u rces o f h e a t.
A t t o d a y ' s p r i c e s , S i 5 .0 0
w o r t h o f wood p r o v i d e s a s many p o t e n t i a l B t u 1s o f h e a t a s
S i 3 0 .0 0 w o r t h o f e l e c t r i c i t y ,
and $ 3 0 .0 0 o f f u e l o i l .
$ 3 6 .0 0 w o rth o f n a t u r a l g a s
T h ese f i g u r e s a r c b a s e d on $ 3 0 / c o r d
wood s p l i t and d e l i v e r e d , $ 0 . 444/kw h e l e c t r i c i t y , $ .0 0 3 6 7 1 /
c u . f t . n a t u r a l g a s and $ 0 . 4 2 / g a l . No. 2 f u e l o i l d e l i v e r e d .
I t m ust b e n o t e d t h a t t h e f i g u r e f o r e l e c t r i c i t y c a n n o t be
d i r e c t l y com pared t o t h e f i g u r e s f o r wood, n a t u r a l g a s and
f u e l o i l b e c a u s e h e a t o u t p u t fro m e l e c t r i c i t y i s 100%
e f f i c i e n t and t h e o t h e r f u e l s o u r c e s a r e a p p r o x i m a t e l y e q u a l
i n e f f i c i e n c y and much l e s s . 3 H o w ev er, t h e c o s t o f c e n t r a l
h e a t i n g s y s te m s on t h e m a r k e t t o d a y t h a t u s e wood a s f u e l
is
p r o h i b i t i v e t o t h e a v e r a g e hom eow ner.
S e c o n d ly , o th e r
p o s s i b l e a l t e r n a t i v e s to th e u se o f c o n v e n tio n a l energy
s o u r c e s , such a s s o l a r h e a t c o l l e c t i o n o r c a p t u r in g th e
e n e r g y o f t h e w in d , a r e n o t y e t s u f f i c i e n t l y p e r f e c t e d t o b e
e c o n o m i c a l l y f e a s i b l e f o r u s e i n an a v e r a g e hqm e.
T h e .u s e
o f wood c a n be an i n t e r i m e n e r g y s o u r c e u n t i l t h e s e a l t e r ­
n a tiv e s are p e rfe c te d .
F i n a l l y , t h e w i d e s p r e a d u s e o f wood
a s a f u e l w o u ld l e a d t o i n c r e a s e d a i r p o l l u t i o n w h ic h c o u l d
---------“
---------- :-------0I n t e r v i e w w i t h
t i v e , May 2 , 1 9 7 8 .
Lyne M a r t i n , M ontana Pow er R e p r e s e n t a ­
p a r t i a l l y b e a l l e v i a t e d w i t h a s y s te m t h a t b u r n s t h e y eo d '
i" V1
m ore e f f i c i e n t l y and d o e s n o t e m it l a r g e p a r t i c u l a t e s o f
carb o n .
Q
O lU U C T lV E S
The f o l l o w i n g o b j e c t i v e s w e re d e v e l o p e d t o a c c o m p l i s h
th e p u rp o se o f th e stu d y :
1.
To d e s i g n a c e n t r a l wood h e a t i n g s y s te m t h a t w ould
i n c l u d e a w o o d - f i r e d b o i l e r and a h e a t s t o r a g e u n i t .
2.
To t e s t t h e e f f i c i e n c y o f t h e c e n t r a l wood h e a t ­
i n g s y s te m .
3.
To com pare t h e c e n t r a J wood h e a t i n g sy s te m t o a
c o n v e n t i o n a l e l e c t r i c a l b e a t i n g s y s te m w i t h r e s p e c t t o f u e l ,
c o sts.
ASSUMPTIONS
The n a t u r e o f t h e s t u d y d i c t a t e d t h a t t h e f o l l o w i n g
a ssu m p tio n s be m ade:
1.
T h a t t h e c u r r e n t e n e r g y s h o r t a g e and i n c r e a s e i n
en erg y c o s t w i l l c o n tin u e .
2.
T h a t wood i s a r e n e w a b l e e n e r g y s o u r c e and w i l l b e
a v a i l a b l e i n many p a r t s o f t h e c o u n t r y .
3.
T h a t t h e wood u s e d w i l l be r e p r e s e n t a t i v e o f i t s
-5 .
;
s p e c i e s a s t o B t u 1s p e r p o u n d .
4.
T hat th e d a ta r e c e iv e d w i l l have im p l i c a ti o n s f o r
t h e f e a s i b i l i t y o f u s i n g a w o o d - f i r e d b o i l e r and h e a t s t o r ­
age u n i t to h e a t a d w e llin g .
5.
T h a t t h e m o i s t u r e i n t h e f i r e w o o d u s e d w i l l be
u n i f o r m and w i l l n o t a f f e c t t h e d a t a c o l l e c t e d .
LIMITATIONS
The i n v e s t i g a t o r was aw are o f t h e f o l l o w i n g l i m i t a ­
tio n s in t h is stu d y :
1.
O nly l o d g e p o l e p i n e w i l l b e u s e d t o f u e l t h e b o i l e r
and t h e r e f o r e , no i n f e r e n c e s c a n b e made a s t o t h e p e r ­
fo r m a n c e o f o t h e r s p e c i e s o f wood u s e d t o f u e l t h e b o i l e r .
2.
Only s t a n d i n g dead t r e e s o f t h e s p e c i e s l o d g e p o l e
p i n e w i l l b e u s e d and t h e r e w ill, b e no a c c o u n t f o r t h e m o is ­
t u r e c o n t e n t o f t h e wood.
3.
T h e r e w i l l b e no q u a n t i t a t i v e e v a l u a t i o n o f t h e
c o n trib u tio n of so la r i n f i l t r a t i o n
t h r o u g h windows i n t h e
house.
4.
The d a t a w i l l o n l y b e a p p l i e d d i r e c t l y t o one
h o u s e i n one p a r t i c u l a r c l i m a t o l o g i c a l l o c a t i o n .
DEFINITION OF TERMS
A l t e r n a t i v e e n e r g y h e a t i n g s y s te m - a h e a t i n g sy s te m
u s i n g wood, w in d o r t h e sun a s an e n e r g y s o u r p e .
B o ile r - w o o d - f ir e d , w a t e r - j a c k e t e d , f i r p tu b e ty p e
b o i l e r n o t d e s i g n e d t o p r o d u c e steam .,
B tu - B r i t i s h T h erm al U n i t w hich e q u a l s w e i g h t i n
pounds tim e s th e change in te m p e ra tu re in degpees F a r e n h e it
tim e s th e s p e c i f i c h e a t o f th e s u b s ta n c e .
C o n v e n t i o n a l e n e r g y h e a t i n g s y s te m - a h p a t i n g sy ste m
u sin g n a tu r a l g a s, e l e c t r i c i t y ,
f u e l o i l o r p r o p a n e a s an
energy s o u r c e ;
H e a t s t o r a g e u n i t - I 500 g a l l o n s t e e l t a p k f i l l e d w i t h
' •
w a t e r , i n s u l a t e d w i t h a minimum o f 12 i n c h e s q f f i b e r g l a s s
in su la tio n .
R v a l u e - r e s i s t a n c e t o h e a t f l o w and e q u a l t o t h e
re c ip r o c a l of th e U v a lu e .
R a d ia to r s - 3 /4 " f i n tu b e s i n s t a l l e d j u s t u n d er th e
— ——
—
.
i
,
f l o o r j o i s t s o f t h e m ain f l o o r o f t h e h o u s e .
S p e c i f i c h e a t - t h e num ber o f B t u ' s r e q u j p c d t o r a i s e
O
t h e t e m p e r a t u r e o f I l b . o f , t h e s u b s t a n c e I F . The s p e c i f i c
-
.
h e a t o f w a ter i s one.
A '
C h a r l e s E . D u l l , M odern P h y s i c s (New io r jc : H e n ry H o l t
a n d Cornpemy, 1 9 4 5 ) , p . 230.
-7 -
*
.
r
.
‘
.<
S y stem - b o i l e r , h e a t s t o r a g e u n i t , r a d i a t o r s OpcJi r e ­
l a t e d p lu m b in g and w i r i n g e x c l u s i v e o f t h e e l e c t r i c a l h e a t ­
i n g s y s te m .
T e m p e r a tu r e d i f f e r e n t i a l - d i f f e r e n c e b e tw e e n t h e
t e m p e r a t u r e i n s i d e t h e h o u s e and t h e t e m p e r a t u r e o u t s i d e t h e
house.
U v a l u e - h o u r l y r a t e o f h e a t t r a n s f e r f o r one s q u a r e
o
f o o t o f s u r f a c e when a t e m p e r a t u r e d i f f e r e n c e o f I F e x i s t s
b e tw e e n t h e a i r on t h e two s i d e s o f t h e s u r f a c e .
5
V a r i a b l e c o s t s - c o s t s o f o p e r a t i o n o f t h e wood h e a t i n g
s y s te m i n c l u d i n g f u e l and m a i n t e n a n c e .
PROCEDURE
D a ta C o l l e c t i o n
I n o rd e r to e v a lu a te th e perfo rm an ce o f th e c e n t r a l
wood h e a t i n g s y s te m and com pare i t t o a c o n v e n t i o n a l e l e c ­
t r i c a l h e a t i n g s y s te m , t h r e e v a r i a b l e s
w e re
amount o f wood u s e d i n t h e w o o d - f i r e d b o i l e r ,
reco rd ed :
amount o f
e l e c t r i c i t y u s e d b y t h e r e s i s t a n c e e l e c t r i c i a n h e a t e r s , and
t e m p e r a t u r e i n s i d e and o u t s i d e t h e h o u s e .
The t e s t p e r i o d
e x t e n d e d f o r f i v e w e e k s . E ach s y s te m was i n o p e r a t i o n s i n g l y
^ S e i c h i K o u z o , J . Raymond C a r r o l l , and H a r la n d D.
B a r e i t h e r , W in t e r A i r C o n d i t i o n i n g (New Y ork: The I n d u s t r i a l
P r e s s , 1958") , p . 1 8 3 .
~
-8 -
on a l t e r n a t i n g week a .
1 ■i::
Wood C o n su m p tio n
The c o n v e n t i o n a l m ethod o f m e a s u r i n g t h e amount o f wood
i s b y v o lu m e .
H ow ever, b e c a u s e t h i s i s v e r y u n r e l i a b l e
when w o r k in g w i t h s p l i t o r u n s p l i t c o r d wood, t h e wood was
w e ig h e d t o e v a l u a t e t h e amount u s e d .
A ll c a l c u l a t i o n s w ere
r e l a t e d t o t h e w e i g h t o f w ood, t h e n i n t e r p o l a t i o n s w ere
made t o v o lu m e «
A beam b a l a n c e s c a l e was u s e d t o w e ig h t h e wood.
A
r e a s o n a b l e amount was w e ig h e d a t t h e b e g i n n i n g o f e a c h week
d u r i n g t h e t im e t h e s y s te m was b e i n g u s e d a s t h e h e a t s o u r c e .
Any wood l e f t i n t h e s t a c k a t t h e e n d o f t h e t e s t p e r i o d
was w e ig h e d and s u b t r a c t e d
E le c tric ity
from t h e t o t a l
fo r th a t w e e k ..
C o n su m p tio n
A c o n v e n t i o n a l w a t t - h o u r m e t e r was u s e d t o r e c o r d t h e
amount o f e l e c t r i c i t y
consumed d u r i n g t h e t e s t p e r i o d i n
w h ic h t h e e l e c t r i c a l r e s i s t a n c e h e a t e r s w ere u s e d t o h e a t
th e h o u se .
tric ity
T h i s m e t e r r e c o r d e d o n l y t h e amount o f e l e c ­
u s e d by t h e h e a t e r s a n d was i s o l a t e d fro m other-
e l e c t r i c a l n eeds of th e house.
T e m p e r a tu r e D i f f e r e n t i a l
One t h e r m o g r a p h was i n s t a l l e d i n s i d e t h e h o u s e t o
g ra p h ic a lly re c o rd th e in s id e tem p era tu re .
A n o th e r
-9 -
t h e r mo g r a p h was i n s t a l l e d on. t h e sh a d e d s i d e pi’ the. h o u s e i n
a p r o t e c t i v e b o x .t o g r a p h t h e a m b i e n t o u t s i d e a i r t e m p e r a ­
tu re .
A t t h e b e g i n n i n g o f. t h e f i v e week t e s t p e r i o d , e a c h
t h e r m o g r a p h was c a l i b r a t e d w i t h a n a c c u r a t e m p r c u r y b u l b
t h e r m o m e t e r ..
The t h e r m o g r a p h s w e re s e t t o r u p f o r one
week w i t h a s e v e n d a y g r a p h i n s t a l l e d arid c h a p g e d w e e k l y .
CHAPTER H
:
REVIEW OF LITERATURE AND RELATED RESEARCH
WOOD AS FUEL
When c o n s i d e r i n g t h e u s e o f wood a s an e n e r g y s o u r c e ,
i t m u st b e e s t a b l i s h e d t h a t wood i s a v a i l a b l e on a ren e w ­
a b le b a s i s f o r use in r e s i d e n t i a l h e a tin g .
I t h a s been
s t a t e d t h a t o n e - t h i r d o f th e w o rld i s e x p e r ie n c in g a s h o r t ­
a g e o f wood t o be u s e d f o r home h e a t i n g and c p o k i n g . ^
In
f a c t , many a r e a s o f t h e w o r l d w e re s a i d t o b e t r e e l e s s w here
e x t e n s i v e f o r e s t s o n c e g re w .
A r e a s o f t h e I n d i a n su b ­
c o n t i n e n t , c e n t r a l A f r i c a and p a r t s o f L a t i n A m e ric a w ere
r e p o r t e d t o e x h i b i t t r e e l e s s r e g i o n s w hich e x t e n d t o a 30
7
m i l e r a d i u s a ro u n d l a r g e r c i t i e s .
H ow ever, t h e s e s h o r t a g e s
seem t o b e a p r o b le m o f l o c a l a r e a s o f h i g h p o p u l a t i o n
d e n s i t i e s h a v i n g a lo w e r s t a n d a r d o f l i v i n g .
In o th e r p a r ts
o f t h e w o r l d , t h e r e i s am ple wood f o r u s e a s f u e l .
Eckholm
s t a t e d : 7*
° E . P . E c k h o lm , L o s i n g Ground (New Y ork: W.W. M o rto n ,
1 9 7 6 ) , p'. 1 0 3 .
.
:
7
J a y W. S h e l t o n , W o o d b u rn e r1s E n c y c l o p e d i a ( W a i t s f i e l d :
Vermont C r o s s r o a d s P r e s s , 1 9 7 6 ) , p 7 .
^
-.1 1 -
" • • . th e re i s l i t t l e p o in t in c a llin g t h i s a
w o r l d p r o b le m , f o r f u e l wood s c a r c i t y , u n l i k e o i l
s c a r c i t y , i s a lw a y s l o c a l i z e d i n i t s a p p a r e n t
d i m e n s i o n s . "8
-
■
i
C o n s i d e r a b l e r e s e a r c h h a s b e e n done t o d e t e r m i n e t h e
a v a i l a b i l i t y o f tim b e r in th e U n ited S ta te s *
S h e lto n f e l t
t h a t a wood s h o r t a g e i n t h e U n i t e d S t a t e s was n o t l i k e l y
to occur f o r th r e e r e a s o n s .
F irst,
th e U n ite d S t a t e s had
many s o u r c e s o f e n e r g y t o c h o o s e fro m and t h e r e f o r e , w o u l d
n e v e r bp w h o l l y d e p e n d e n t on one o f t h e s e s o u r c e s .
Second.,
some f o r e s t s e x i s t e d a s v e r y s t a b l e e c o s y s t e m s and t h u s ,
w i l l b e a b l e t o t a k e t h e p r e s s u r e s man
w i l l im pose bn th e m .
I t h a s b e e n n o t e d t h a t when t h e s e e c o l o g i c a l l y s t a b l e f o r e s t s
a r e c l e a r e d and t h e n a b a n d o n e d , t h e t r e e s r e t u r n e d v e r y
q u i c k l y a s i f t h e y w e re i n f a c t w e e d s .
F in a lly , le g is la tio n
th a t b rin g s about c o n tro l of d e s tru c tiv e f o r e s t p r a c tic e s
9 •
w i l l become s t r o n g e r
S h e l t o n w e n t on t o s a y t h a t m ost o f t h e wood grown i n
t h e U n i f e d S t a t e s i s n o t u s e d b u t d e c a y s and f h a t "a c o n if)
s f d e r a b l e e x p a n s i o n o f wood u s e i s p o s s i b l e . . A' s t u d y
done by t h e S t a t e o f Vermont f o u n d t h a t t h e a c t u a l s u s t a i n e d
8E c k h o lm , p . 1 0 4 .
9SheJ t o n , p . 8 . .
10I b f d . , p . 7 .
.
• .
. ,
•
,
.
‘
•
i
• -
g ro w th i n t h e f o r e s t s o f Vermont was r o u g h l y
c u r r e n t annual h a r v e s t .
*
,
I
f i v e t i j n e s t |i c
I t was n o t e d t h a t t h i s a r e a i s a
m a jo r lu m b e r and pulpwood. p r o d u c e r .
T h i s s u s t a i n e d g ro w th
r a t e o f 1 / 4 - 3 / 4 o f a c o r d p e r a c r e c o u ld b e d p u b le d w i t h
im p ro v e d f o r e s t m anagem ent p r o c e d u r e s such a s t h i n n i n g ,
I
-
c u t t i n g l e s s p r o d u c t i v e i n d i v i d u a l t r e e s and p a r v e s t i n g a t
11
t h e m o st p r o d u c t i v e t i m e . "
■
A l t h o u g h s h o r t a g e s i n v o l v i n g q u a l i t y and size i n c e r ­
t a i n t i m b e r s p e c i e s may o c c u r-, t h e r e seem s t o b e am ple wood
i n th e U n ited S t a t e s t h a t i s
s u i t a b l e f o r u s e a s f u e l wood.
I n a s t u d y c o n d u c t e d by t h e U n i t e d S t a t e s F o r p s t S e r v i c e ,
r e p o r t e d i n Gay, on t h e p o t e n t i a l f u e lw o o d a v a i l a b l e p e r
y e a r i n v a r i o u s r e g i o n s o f th e U n ited S t a t e s ,
th a t,
i t was r e p o r t e d
a f t e r t i m b e r h a r v e s t and n a t u r a l m o r t a l i t y h a d b e e n
a c c o u n t e d f o r , t h e r e was a n e t a n n u a l g ro w th o f 61 m i l l i o n
c o r d s o f h a rd w o o d s and 56 m i l l i o n c o r d s o f s o f t w o o d s i n t h e
e a s t e r n f o r e s t s and 1 . 6 m i l l i o n c o r d s o f h a rd w o o d and 3 .4
m i l l i o n c o rd s o f so ftw o o d s i n th e f o r e s t s o f th e n o r th e r n
I2
Rocky M o u n t a i n s . "
When t h e amount o f s o f tw o o d a l o n e f o r
■ ^ S t a t e o f V e rm o n t, R e p o r t on t h e G o v e r n o r 's T ask F o r c e
on Wood a s a S o u r c e o f E n e r g y , 1 9 7 5 .
ip
L a r r y Gay, The C o m p le te Book o f h e a t i n g W ith Wood,
( C h a r l o t t e , Vermont"-" G a rd e n Way P u b l i s h i n g , 1 9 7 4 ) , pi 1 5 .
—L3 —
i l l c n o r t h e r n R o c k y M o u n t a i n s w a s d i v Lrlcd by 5 . c o r d s p e r
y e a r f o r an a v e r a g e A m e ric an home, enough c o r d wood was o b 13
t a i n e d f o r . 6 8 0 ,0 0 0 h o u s e h o l d s . '
I t . s h o u ld bp n o t e d t h a t
some o f t h i s a n n u a l g ro w th was i n a r e a s t h a t a r e i n a c c e s s ­
i b l e ; h o w e v e r , t h e s e f i g u r e s w ere r e p o r t e d a f t e r d e d u c t i n g
l o g g i n g w a s t e s , o l d age and d i s e a s e l o s s e s ,
and b lo w downs.
Much o f t h i s t y p e o f wood c o u l d b e s u i t a b l e f p r f u e l wood.
I t m ust a l s o b e e s t a b l i s h e d w h e t h e r an i n c r e a s e i n t h e
u s e o f t i m b e r f o r f u e l wood w ould h i n d e r t h e lu m b e r i n d u s t r y
Gay e x p l a i n e d :
" . . . t a k i n g wood f o r f u e l from t h e f o r e s t s
s h o u ld n o t com pete w i t h t h e lu m b e r i n d u s t r y a t
a ll.
On t h e c o n t r a r y , i t s h o u l d l e a d t o much
g r e a t e r p r o d u c tio n o f q u a l i t y t i m b e r . "Id
FUELWOOD COSTS VS. CONVENTIONAL ENERGY SOURCES
In 1978,
firew ood
i n M ontana v a r i e d
S i 5 .0 0 per cord fo r m i l l
S '1 0 .0 0 p e r c o r d f o r
th at is
purchased
common p r i c e
near the
1.6.
is
not
c u t , s p i t V, d e l i v e r e d
end o I
w a s SoO . 0 0 p e r c o r d
I 3 T h id .,|) .
1 4 TbicI. ,
scrap th a t
in
co st.fro m
d eliv ered
a n d s l a c k e d wood
the h e a t i n g
lor
to
c o r d wood
season.
A
Lha < i s cut. 413
.
I
■ •
and d e l i v e r e d . ' v 1’lic datum i n T a b le a , j). j.G
.
'
'
i' ' ; :
t h i s average p r i c e .
V
w a s b a s e d on
N a tiu ra l g a s i n May o f 1978 was p r i c e d a c c o r d i n g t o
th e fo llo w in g sc h e d u le :
TABLE I 16
NATURAL GAS PRICE SCIIEDULE
Increm en t
(M-t h o u s a n d )
P ric e per
th o u sa n d c j j . f t .
f i r s t IdOO c u . f t .
n e x t 99 M c u . f t .
8 5 .1 6 1 9
2 .2 2 8 4
n e x t 200 M c u . f t .
n e x t 700 M c u . f t .
1 .8 9 2 8
I .6 9 3 4
I t h a s b e e n f o u n d t h a t t h e r e a r e 950 B t u 1s
* p er c u b ic fo o t
17
of n a tu ra l g a s . '
E l e c t r i c i t y was s o l d i n May o f 1978 a c c o r d i n g t o t h e
fo llo w in g sc h ed u le :
is
16
Bozeman D a i l y C h r o n i c l e , March I,. 1 9 7 8 , p . 2 9 .
I n t e r v i e w w i t h Lyne M a r t i n , M ontana Power R e p r e s e n t ­
a t i v e , May 2 , 1 9 7 8 .
17
1 Ifrid .
-1 5 -
.
TAnLM 218
ELECTRICITY PRICE SCHEDULE
Increm ent
f i r s t 20 kwh
n e x t 80 kwh
n e x t 100 kwh
a d d i t i o n a l kwh
P ric e per
k ilo w a tt hour
.•
SO .0369
0 .0 5 3 8
0 .0 3 7 6
0 .0 1 9 8
One k i l o w a t t h o u r was r e p o r t e d t o c o n t a i n 3415 B t u l s .
:Q
B o th No. 2 f u e l o i l and p r o p a n e w ere p r i c e d a t SO .42
p e r g a l l o n i n May, 1 9 7 8 .
Fuel o i l c o n t a i n s .140,000 B i n ' s
O 0
p e r g a l l o n and p ro p a n e c o n t a i n s 9 8 ,6 0 0 B i d ' s p e r g a l l o n . ‘t
The c o s t s o f t h e s e p u r c h a s e d f u e l s a r e r e p o r t e d i n T a h Te 31
18I b i d .
Y ork:
1 ^ Q r o f f C o n k l i n , The W e a th e r C o n d i t i o n e d House
R e i n h o l d P u b l i s h i n g C o r p . , .1958), p , 1 6 7 .
20Martini .
■
'
\
(New
TABLE 3
COMPARATIVE PRICES OF SELECTED FUELS
Fuel
P r i c e o f one
m illio n B tu ' i
Wood ( l o d g d p o l e p i n e )
N a tu ra l gas
E le c tric ity
F u e l O il (No. 2)
P ropane
S i . 71'
5 .4 2
1 0 .1 5
3 .0 0
4.5Q
I t sh o u ld be n o te d t h a t th e e f f i c i e n c y o f e l e c t r i c
h e a t e r s i s 100% and t h e e f f i c i e n c y o f t h e f u r n a c e s t h a t u s e
t h e o t h e r f u e l s i n t h e t a b l e r a n g e d from 50% t o 80%.
FUELWOOD PROPERTIES
D i f f e r e n t s p e c i e s o f fu e lw o o d h a v e d i f f e r e n t B tu r a t ­
in g s p e r co rd .
T h i s i s p r i m a r i l y due t o t h e f a c t t h a t d i f ­
f e r e n t s p e c i e s o f. wood h a v e d i f f e r e n t d e n s i t i e s .
I t has
b e e n f o u n d t h a t m o st woods h a v e t h e same num ber o f - B tu 1s
°1
p e r pound o f o v e n d r i e d w ood. “
As a r e s u l t , f*16 m ost
a c c u r a t e m e th o d o f d e t e r m i n i n g t h e num ber o f B t u ' s i n a
q u a n t i t y o f wood i s b y w e i g h t .
^ D a v i d L y l e , The L ange S to v e C a t a l o g anfl Wood H e a t
G uide ( A l s t e a d , N.HTi
Sca h d in a v ia n S to v e s , I n c . , 1976) p . 15.
-1 7 -
I t h a s b e e n r e p o r t e d by a number o f a u t h o r s t h a t t h e
'
' ■
'
5
' ? ■ :
e n e r g y g i v e n o f f d u r i n g c o m b u s tio n o f o n e -p o u |id o f d r y wood
was a b o u t 8600 B t u ' s .
O2
.
T h i s h e l d t r u e f o r a l l woods e x c e p t
th o s e w ith h ig h r e s i n c o n te n t.
T a b l e 4 was p r e p a r e d from
r e s e a r c h d a t a d e v e l o p e d by S h e l t o n and L y le w hich l i s t s
d e n s i t i e s and B t u ' s p e r pound f o r d i f f e r e n t wpods fo u n d i n
th e W e s t- ^
TABLE 4
POTENTIAL ENERGY OE VARIOUS WOOD SPECIES
S p e c ific
. G ra v ity
S p e c ie s
A ld e r, re d
A sh, O regon
A s p e n , Q u a k in g
C o tto n w o o d , b l a c k
O ak, w h i t e
C edar, w e stern re d
D o u g la s f i r , I n t e r i o r
West
P in e , Jack
L o d g e p o le .
Ponderosa
Redwood
S p r u c e , E ngelm an
S itk a
ib s /c u .ft .
m illio n
B tu /c o rd
2 5 .5
3 4 .2 7
2 3 .6 7
2 1 .8 1
1 7 .5
2 3 .6
1 6 .3
1 5 .0
1 2 .3 6
2 9 .2
1 3 .6
.41
.5 5
.3 8
.3 5
.6 8
.3 2
■
.5 0
1 9 .9 4
3 1 .1 5
.4 3
.41
2 6 .7 9
2 5 .5
. 40
.4 0
.3 5
.4 0 ...
2 4 .9 2
2 4 .9 2
2 1 .8 1
2 4 .9 2
2 1 .4
.
2 0 .6
1 7 .5 '
1 7 .1
1 7 .1
1 5 .0
1 7 .1
^ 2L y l e , p . 1 5 ; G ay, p . 39; S h e l t o n , p . 1 8 .
25S h e l t o n , p p . 1 8 - 2 1 ; L y l e , p. 1 7 .
'I
-.1 8 -
HOILER AND tIEAI' STOWAGE UMJT DESMiN
The d e s i g n o f a b o i l e r and h e a t s t o r a g e u n i t f o r a
r e s i d e n t i a l , b u i l d i n g i s d e p e n d e n t on a number o f f a c t o r s .
The f i r s t c o n s i d e r a t i o n i s t h e amount o f h e a t l o s s t h r o u g h
th e b u ild in g m a t e r i a ls used i n th e b u ild in g .
A h e a tin g
s y s te m m u st be a b l e t o p r o v i d e t h i s amount o f h e a t t o make
up f o r t h e h e a t l o s s .
U sin g t h i s v a l u e o f h e a t l o s s and a
s p e c i f i e d p e r i o d o f t i m e , a d e t e r m i n a t i o n c a n be made a s t o
t h e amount o f h e a t t h a t i s n e e d e d i n s t o r a g e .
The s i z e o f
t h e f i r e box c a n t h e n b e .c o m p u te d on t h e b a s i s o f t h e number
o f B t u ' s n e e d e d t o b e t r a n s f e r r e d t o s t o r a g e and t h e number
o f B t u ' s t h a t a r e a v a i l a b l e i n t h e s p e c i e s o f wood b e i n g
used.
The b o i l e r m ust h a v e t h e n e c e s s a r y h e a t a b s o r p t i o n
a r e a t o t r a n s f e r t h e a v a i l a b l e e n e r g y i n t h e yrood t o t h e
h e a t sto ra g e u n it.
BUILDING HEAT IDSS
Numerous m e th o d s h a v e b e e n d e v e lo p e d t o c a l c u l a t e t h e
h e a t l o s s in a d w e llin g .
The g e n e r a l l y a c c e p t e d m ethod
was one r e p o r t e d by K o n z o , C a r r o l I and B a ri e t h e r u s i n g t h i s
fo rm u la :
OA
24
S e i c h i K o n z p , J . Raymond C a r r o l l , and I j a r l a n d D.
B a r e i t h e r , W in t e r A i r C o n d i t i o n i n g (New Y ork: The I n d u s t r i a l
P r e s s , 1 9 5 8 ), p . 183.
- I . fi­
ll rr A ( U ) ( t . < l . )
w h ere:
H = t h e d e s i g n h e a t l o s s i n )i/tu /h r
A '= t h e a r e a t h r o u g h w hich h e a t l o s s t a k e s
p la c e , in square f e e t
U = th 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
t . d . - t h e t e m p e r a t u r e d i f f e r e n c e assum ed
b e tw e e n i n d o o r - a i r an<3 o u t d o o r - a i r
te m p e ra tu re s, under d e sig n c o n d itio n s
H e a t L o s s A re a
The a r e a o f a l l s u r f a c e s w here h e a t l o s s o c c u r s such
a s c e i l i n g s , w a l l s , windows and d o o r s i s i t e m i z e d and r e ­
c o r d e d on a w ork s h e e t .
F o r e a c h o f t h e s e a r e a s t h e r e was
25
a re p o rte d h e a t lo s s c o e f f ic ie n t.
H eat L oss C o e f f i c ie n t
D i f f e r e n t m a t e r i a l s a rc re p o r te d to have d i f f e r e n t h e a t
lo ss c o e ffic ie n ts.
T a b le 5, p . 2 0 , was d e v e l o p e d from i n ­
f o r m a t i o n by C o n k l in and t h e R u r a l E l e c t r i f i c a t i o n . A d m i n i s ­
t r a t i o n and l i s t s
a l l th e m a t e r i a ls t h a t a re psed i n th e
26
house r e p o r te d i n t h i s stu d y .
25I M d r
26C O n k lin , p p . 1 9 - 2 2 ; U .S . D e p a r tm e n t o f A g r i c u l t u r e ,
R u r a l E l e c t r i f i c a t i o n A d m i n i s t r a t i o n , E l e c t r i c House H e a t i n g ,
REA B u l l e t i n 1 4 2 -1 ( I 9 6 0 ) , p p . 1 5 - 1 6 .
-2 0 -
TABLE 5
HEAT LOSS COEFFICIENTS OF VARIOUS BUILDING MATERIALS
T h ic k n e s s
(in .)
. R e sista n c e
(R)
S h e e tro c k
1 /2
.4 5
Plyw ood
1 /2
.6 3
M a terial
Plyw ood
••
Wood f i b e r b o a r d
I
1 .2 5
I
2 .3 8
B u ild in g paper:
v a p o r-p e rm e a b le f e l t
vapor s e a l , p l a s t i c film
.0 6
0 ,0 0
C o n c rete:
sa n d and g r a v e l o r s t o n e
a g g re g a te (n o t d rie d )
R o o fin g :
B lan k et or b a t t ,
Windows:
d o u b le g l a s s ,
space
D o o rs:
I
g la ss
1 /4 " a i r
.0 8
1 .1 9
wood s h i n g l e s , d o u b le
In su la tio n :
fib e r
'
I
3 .7 0
1 /4
1 .6 4
s t e e l s h e e t , foam c o r e
1 9 .0
The num ber o f s q u a r e f e e t o f e a c h s u r f a c e i n t h e b u i l d ­
i n g t h a t w i l l l o s e h e a t was m u l t i p l i e d by i t s p a r t i c u l a r
h e a t l o s s f a c t o r (R) and t h e d e s i g n t e m p e r a t u r e d i f f e r e n c e i n
o rd e r to e s t a b l i s h th e t o t a l h e a t l o s s per hopr in th e
b u ild in g .
27
07
K o n z o , C a r r o l l , and B a r e i t h e r , p . 1 8 3 .
i'
D e s ig n T e m p e r a tu r e D i f f e r e n c e
D i f f e r e n t a r e a s o f th e U n ited S t a t e s have a d i f f e r e n t
lo w a n n u a l a v e r a g e t e m p e r a t u r e , arid t h e p a r t i c u l a r d e s i g n
te m p e ra tu re f o r th e l o c a l i t y un d er stu d y needed to be
id e n tifie d .
lis ts
T a b l e 6 , d e v e lo p e d fro m i n f o r m a t i o n by J e n n i n g s ,
some d e s i g n t e m p e r a t u r e s o f a r e a s a p p l i c a b l e t o t h i s
s t u d y arid O t h e r s t o b e u s e d a s a c o m p a r i s o n .
TABLE 6 23
OUTDOOR DESIGN TEMPERATURE
S t a t e and C i t y
D e s ig n Temp. ( F )
M ontana
B illin g s
B u tte
H avre
H e le h a
-25
-20
-30
-20
M aine
E a stp o rt
L e w is to n
-10
-1 5 ■ '
M in n e s o ta
D u lu th
M in n e a p o lis
S t . Paul
A rizo n a
F la g sta ff
P h o e n ix
T u cso n
.
-25
-20
-20
-10
25
25
-
..
28B u r g e s s H. J e n n i n g s , H e a t i n g and A i r G o i i d i t i o n i n g
(S c ra n to n :
I n t e r n a t i o n a l T e x tb o o k Company, 13)56), p p . 1 4 8 -5 0
-22-
W ith t h e d e s i g n t e m p e r a t u r e o f t h e l o c a l i t y known,
was t h e n p o s s i b l e t o c a l c u l a t e t h e d e s i g n t e m p e r a t u r e dif-r ..
ference ( t .d .
i n t h e f o r m u l a on p a g e 1 9 ) .
Thp a c c e p t e d
c o m f o r t a b l e i n s i d e t e m p e r a t u r e was r e p o r t e d tp. be 7 0 ° F .
The d i f f e r e n c e i n t h e d e s i g n t e m p e r a t u r e f o r ^ n s i d e t h e
d w e l l i n g and t h e d e s i g n t e m p e r a t u r e f o r t h e p a r t i c u l a r l o ­
c a l i t y e q u a l l e d t h e d e s i g n t e m p e r a t u r e d:i f f e r p n c e .
H eat L oss to I n f i l t r a t i o n .
H e a t l o s s I t u 1Ough aii* i n f i l t r a t i o n was r e p o r t e d t o b e
a n o th e r s i g n i f i c a n t c o n tr ib u to r to h e a t l o s s in a b u ild in g .
I n f i l t r a t i o n was d e s c r i b e d t o b e ^he i n f l o w o f c o l d a i r
t h r o u g h c r o c k s a ro u n d windows and d o o r s and t h r o u g h s p a c e s
b e tw e e n b u i l d i n g m a t e r i a l s .
The c o e f f i c i e n t o f b e a t l o s s (U) i s f o u n p b y m u l t i p l y ­
in g th e s p e c i f i c h e a t o f a i r (0 .2 4 ) tim e s th e d e n s ity of
a i r (0 .0 7 5 ) to eq u al 0 .0 1 8 .
The U v a l u e o f t ji e a i r i s t h e n
m u l t i p l i e d by t h e volum e o f a i r t h a t e n t e r e d t h e h o u s e e ac h
30
h o u r . T h i s m ethod was r e p o r t e d by C o n k l i n . . One C om plete
a i r c h a n g e p e r h o u r by volum e i n s i d e t h e h d u sp was r e p o r t e d
31
t o be a r o u g h e s t i m a t e . '
29F.W . H u t c h i n s o n , D e s ig n o f H e a t i n g and V e n t i l a t i n g
S y s te m s (New Y ork: The I n d u s t r i a l P r e s s , 1 9 5 § ) , p . 25.
30C o n k l i n , p . 3 8 .
31K c n z o , C a r r o l , and B a r e i t h e r , p . 2 1 0 .
Ixi sum m ary, i t
s h o u l d be n o t e d t h a t ,
c o n s id e r a tio n of each d e t a i l ,
even w ith c a r e f u l
c a lc u la tio n of h e at lo s s in
a b u i l d i n g c a n o n l y be c o n s i d e r e d an e s t i m a t e .
"No h e a t l o s s c a l c u l a t i o n , no m a t t e r how c a r e ­
f u l l y m ad e , c a n be more t h a n an a p p r o x i m a t i o n .
E ven u n d e r t h e b e s t c o n d i t i o n s . . . i t i s
.
d o u b t f u l w h e t h e r any d e s i g n h e a t l o s s v a l u e i s
w i t h i n 10 p e r c e n t o f t h e t r u e h e a t l o s s f i g u r e . 1
HEAT STORAGE UNIT
The h e a t s t o r a g e u n i t m ust be a b l e t o s t o r e enough
h e a t t o h e a t th e house a t th e d e sig n te m p e r a tu re f o r a s p e c i ­
f i e d p e rio d o f tim e .
E or t h i s s t u d y w a t e r was u s e d a s a
h e a t s t o r a g e medium due t o t h e f a c t t h a t i t was c h e a p and
t h a t t h e r e was e q u ip m e n t a v a i l a b l e t o be u s e d w i t h w a t e r f o r
h e a t t r a n s f e r i n th e sy ste m .
In a d d itio n , w a ter h as a h ig h
s p e c i f i c h e a t and t h e r e f o r e can s t o r e a h i g h am ount o f h e a t
b y v o lu m e . '
BOILER HEAT ABSORPTION AREA
The l i t e r a t u r e t h a t r e l a t e d t o b o i l e r d e s i g n was l i m i t e d
t o s te a m p r o d u c t i o n and i n m ost c a s e s was w r i t t e n m ound t h e
32I b i d . , p . 1 8 4 .
33C h a r l e s E . D u l l , M odern P h y s i c s (New Y ork:
H o l t and Company, 1945)V P - 230'.
Henry
-2 4 -
tu rn of th e c e n tu ry .
H ow ever, t h e r e p o r t e d d a t a were, a p p l i ­
c a b le to t h i s stu d y becau se th e p r i n c i p l e s o f h e a t t r a n s f e r
have n o t chan g ed .
The o l d e r m eth o d o f d e t e r m i n i n g t h e num ber o f B t u 1s
t h a t w e re a b s o r b e d t h r o u g h s t e e l w a l l s o f a b o i l e r . u s e d a
concept of h orsepow er.
The m ethod o f d e t e r m i n i n g t h e number
o f horsepow er i n a p a r t i c u l a r b o i l e r in v o lv e d d iv id in g th e
i n s i d e s u r f a c e a r e a o f t h e b o i l e r by 1 0 . ^
T h is f i g u r e
was t h e n m u l t i p l i e d by a c o n s t a n t f o r a p a r t i c u l a r t h i c k n e s s
o f c a r b o n s t e e l t o f i n d t h e num ber o f B t u ' s p e r h o u r t h a t
t h e b o i l e r w o u ld e x t r a c t from t h e b u r n i n g f u e l / 1
A l a t e r m eth o d o f c a l c u l a t i n g t h e h e a t a b s o r b e d i n a
b o i l e r u s e d a f o r m u l a d e v e l o p e d by t h e Babcock an d W ilc o x
C om pany:^
Q = U^S At
. ^ T h e o d o r e H. T a f t , E le m e n t a r y E n g i n e e r i n g Thermo­
d y n a m ic s (New Y ork: The I n d u s t r i a l P r e s s , I OSorT, P • 55.
35
O t t o de L o r e n z i , C o m b u stio n E n g i n e e r i n g (New Y ork:
C o m b u stio n E n g i n e e r i n g Company, I n c . , 1 9 3 3 ) , p . 158..
^ T h e B a b co c k and W ilc o x Company, S te am , I t s G e n e r a t i o n
an d Use (New Y ork: The B abcock and W ilc o x Company, 1 9 6 3 ) ,
p . 5-7.
-2 5 -
w h e re :
Q - c o n d u c tiv e h e a t t r a n s f e r i n B t u 's p e r
hour
U = c o n d u c ta n c e o f t h e m a t e r i a l u s e d i n
a
B t u 's p e r s q u a r e f o o t p e r h o u r
S = su rfa c e a re a
A t = t e m p e r a t u r e d i f f e r e n c e p a u s in g h e a t
f lo w
A c l o s e a p p r o x im a tio n c a n t h e n be made a s t o tjie s u r f a c e
a r e a i n s i d e t h e b o i l e r e x p o se d t o h e a t t r a n s f e r .
CHAPTER I I I
SYSTEM DESIGN
When c o n s i d e r a t i o n i s g iv e n t o t h e d e s ig n o f a h e a t i n g
sy s te m f o r a d o m e s tic b u i l d i n g , t h e f i r s t unknown t h a t m ust
b e fo u n d i s t h e t o t a l h e a t l o s s i n t h e b u i l d i n g .
U sin g
t h i s f i g u r e , t h e s i z e o f t h e h e a t s t o r a g e u n i t and t h e s i z e
o f t h e b o i l e r c a n t h e n be f o u n d .
BUILDING HEAT LOSS
The l o c a t i o n and t y p e s o f b u i l d i n g m a t e r i a l s t h a t a r e
s u b j e c t t o h e a t l o s s i n t h e h o u se u n d e r s tu d y a p p e a r i n
T a b le 7 , p . 2 7 .
The d a t a i n t h i s t a b l e sum m arize t h e num­
b e r s o f s q u a r e f e e t o f e a c h b u i l d i n g sy ste m ( w a l l s , c e i l i n g ,
e t c . ) t h a t have a s im ila r c o e f f ic ie n t o f h e a t l o s s .
f i g u r e s w ere t h e n u s e d i n T a b le
8
l o s s th r o u g h e a c h b u i l d i n g s y s te m .
T hese
to f in d th e t o t a l h e a t ,
Tlie t o t a l pum ber o f
s q u a r e f e e t w as m u l t i p l i e d by t h e c o e f f i c i e n t o f h e a t l o s s
f o r t h a t s y s te m .
The U f a c t o r f o r e a c h b u i l d i p g sy s te m was
fo u n d b y a d d in g t h e U f a c t o r s f o r a l l t h e co m p o n e n ts u se d i n
e a c h b u i l d i n g s y s te m .
F o r e x a m p le , t h e U f a c t o r f o r th e
c e i l i n g i s an a d d i t i o n o f t h e s h e e t r o c k u s e d (Ji=.4 5 ) and t h e
f i b e r g l a s s i n s u l a t i o n ( R - 3 .7 0 p e r in c h o r 4 4 .4 f o r 12 i n c h e s )
TABLE 7
SQUARE FOOTAGE OF BUILDING SYSTEMS IN THE HOUSE
C e ilin g
( s q . f t , .)
F a m ily Room
K itc h e n
S tu d y
U t i l i t y Room
L iv i n g Room
M a s te r Bedroom
Bedroom # 2
Bedroom # 3
F lo o r
W a lls ( e x t . ) D o o r s ( e x t . )
(sq . f t . )
(sq . f t . )
(sq . f t . )
204
144
O
120
96
108
108
200
O
0
150
325
180
115
130
150 •
325
180
115
130
208
204
120
■
96
48
42
17
16
17
O
O
O
O
20
O
0
O
O
8
90
46
20
62
129
0.
144
48
48
20
9
1682
221.
40
293
H a ll
M a s te r B athroom
39
39
120
120
B athroom
E n tr y
62
129
1682
TOTAL
.480
256
20
Windows
( s q . f t .)
.
8
-2 8 -
I o r a t o t a l R v a lu e o f 4 4 .8 5 .
The R v a lu e s y m b o liz e s th e
r e s i s t a n c e t o h e a t flo w an d i s t h e r e c i p r o c a l o f t h e U v a lu e
(h e a t lo s s c o e f f ic ie n t) .
As a r e s u l t ,
4 4 .8 5 (|1 v a lu e f o r
t h e c e i l i n g s ) i s d i v id e d i n t o o n e , g i v i n g t h e IJ v a lu e f o r
t h e c e i l i n g b u i l d i n g s y s te m .
The p r o d u c t o f t h e a r e a and
t h e h e a t l o s s c o e f f i c i e n t i s t h e n m u l t i p l i e d by t h e d e s ig n
t e m p e r a t u r e d i f f e r e n c e t o e q u a l t h e h e a t l o s s p e r h o u r, th r o u g h
e a c h s e p a r a t e b u i l d i n g s y s te m .
TABLE
8
TOTAL HEAT LOSS IN BTU PER HOUR BY
TRANSMISSION AND INFILTRATION
S tru c tu re
c e ilin g s
flo o rs
w a lls
d o o rs
w indow s
in filtra tio n
A re a o r
Volume
(s q .f t,
or cu. f t . )
U
F a c to r
1682 s q . f t . . 0 2 2
1682
"
.1 6 8
.0 4 0
1768
"
40
293
90
3 3 3 0 .3 6
2 8 2 5 .7 6 . ■
6 3 6 4 .8
1 8 0 .0
10
90
.0 5 0
.6 0 9
90
3364 c u . f t . .0 1 8
90
"
H eat
L o ss
P e r Hour
(B tu )
D e sig n
T e m p e ra tu re
D iffe re n c e
(°F )
90
TOTAL H e at L o ss i n B t u / h r .
The d e s i g n te m p e r a t u r e d i f f e r e n c e i n T a b le
1 6 0 5 9 .3 3
5 4 4 9 .6 8
3 4 2 0 9 .9 3
8
i s c a l­
c u l a t e d by s u b t r a c t i n g t h e low a n n u a l a v e ra g e f p r t h e l o c a l ­
i t y o f t h e s tu d y ( - 2 0 ° F ) fro m a c o m f o r ta b le home i n t e r i o r
-2 9 -
te m p e ra tu re ( 7 0 ° F ) .
T h is g i v e s t h e d e s ig n t e m p e r a t u r e
d i f f e r e n c e f o r a l l b u i l d i n g s y s te m s e x p o se d t o t h e o u t s i d e „
I t s h o u ld b e n o te d t h a t t h e d e s ig n t e m p e r a t u r e d i f f e r e n c e
f o r t h e f l o o r s i s much lo w e r b e c a u s e t h e b a se m e n t i s to b e
h e a te d .
The p r o d u c t s o f t h e a r e a , U f a c t o r and d e s ig n
te m p e ra tu re d if f e r e n c e a re th e n t o t a l e d to f in d th e t o t a l
h e a t l o s s in th e h o u se u sed in th e s tu d y .
The am ount o f a i r i n f i l t r a t i o n i s fo u n d b y f i n d i n g t h e
t o t a l volum e o f a i r i n t h e h o u s e and u s i n g o n e - f o u r t h o f
th a t fig u re
( o n e - f o u r t h o f t h e a i r i s d i s p l a c e (I e v e ry h o u r ) .
A new home may h a v e o n e - h a l f o f t h e a i r d i s p l a c e d e v e ry
h o u r.
H ow ever, due t o t h e f a c t t h a t t h e h o u se u s e d d u r in g
t h e s tu d y h a s an u n i n t e r r u p t e d p l a s t i c f iJ m a s a v a p o r
b a r r i e r , m a g n e t i c a l l y s e a l e d s t e e l d o o rs and w indow s t h a t
w e re i n s t a l l e d
and i n s u l a t e d w ith c a r e , a v a lu e o f o n e -
f o u r t h o f t h e volum e b e in g d i s p l a c e d e v e ry houp was u s e d .
It
s h o u ld b e n o te d t h a t e v e n th o u g h t h e w indow a r e a
w as a s m a ll f r a c t i o n o f t h e t o t a l a r e a exposed, t o h e a t l o s s ,
t h e h e a t l o s s th r o u g h t h e w indow s i s a J m ost e q u a l t o t h a t
o f t h e o t h e r a r e a s com bined (w indow s— 1 6 0 5 9 .3 3 B tu p e r h o u r
h e a t l o s s , com bined o t h e r a r e a s — 1 8 1 5 0 .6 0 B tu p e r h o u r h e a t
57B u rg e s s H. J e n n i n g s , H e a tin g and A ir C o n d i ti o n i n g
( S c r a n t o p : I n t e r n a t i o n a l T ex tb o o k C o ., 1 9 5 6 ) ,: p . 1 5 2 .
-3 0 -
lo s s ,
d a ta from T a b le
8
, p . 2 8 ).
The w indow s u s e d w ere
A n d e rso n th e rm o p a n e w indow s and t h e i r h e a t l o s s c o u ld be
g r e a t l y r e d u c e d th r o u g h t h e u s e o f a d d i t i o n a l sto rm w indow s.
HEAT STORAGE UNIT
H av in g fo u n d t h e t o t a l h e a t l o s s i n t h e h o u se (3 4 2 0 9 .9 3
B tu p e r h o u r ) , i t i s p o s s i b l e t o c a l c u l a t e t h e s i z e o f th e
h e a t s to ra g e u n it n eed ed .
Two f a c t o r s a r e in v o lv e d when
d e te r m in in g t h e s i z e o f t h e h e a t s t o r a g e u n i t .
F i r s t i t was
d e te r m in e d t h a t t h e h e a t s t o r a g e u n i t s h o u ld h o ld enough
h e a t t o k e e p th e h o u se a t 70°F w ith an o u t s i d e t e m p e r a tu r e
o f - 2 0 ° F f o r a t lo c is t 3b h o u rs^
U sin g a t e m p e r a t u r e d i f f e r ­
e n c e o f IOO0F i n t h e t cinlv-X'l00°F minimum f o r e f f e c t i v e
h e a t i n g t o a maximum o f
2 0 0 °F ),
J t w as th e n p o s s i b l e to
c a l c u l a t e th e s iz e o f th e s to ra g e ta n k .
The f o l l o w i n g f o r ­
m u la was d e v e lo p e d by t h e r e s e a r c h e r f o r t h i s p u r p o s e .
v
( Hl o s s )
( A t) ( W ) ( S v i -
W
w h e re :
\
\
\
\
S’ 15
W
P
S
)
cjo-f l i t
volum e o f h e a t s t o r a g e medium
l o s s hBet au t/ hlro) s s p e r h o u r i n h o u se (3 4 2 0 9 .9 3
A t =- te m p e r a tiu 'c d i f f e r e n c e i n t a n k , m axi­
mum m in u s minimum (IO O jF )
w e ig h t i n p o u n d s o f s t o r a g e medium ( w a te r
= 8 .3 l b s / g a l )
h e a t l o s s p e r h o u r i n h o u se (3 4 2 0 9 .9 3 B fu /
3 1
\
-3 1 -
S
- s p e c i f i c h e a t o f s t o r a g e medium ( s p e c i ­
f i c h e a t o f w a te r - 1 . 0 0 )
so :
ir
(3 4 2 0 9 .9 3 ) (3 6 )
■" ( 1 0 0 ) ( 8 . 3 ) ( I )
- 1 4 8 3 .8 g a l .
U sin g t h i s f i g u r e f o r th e num ber o f g a l l o n s i n s t o r a g e ,
a t a n k m e a s u rin g f o u r f e e t i n d ia m e te r and s i x t e e n f e e t i n
l e n g t h w as o r d e r e d .
T h is ta n k was c a l c u l a t e d t o h a v e a
1 5 0 4 .0 3 g a l l o n c a p a c i t y .
BOILER
The s i z e o f t h e f i r e b o x was o f i n i t i a l c o n c e rn b e c a u s e
i t w as th o u g h t t h a t i t
s h o u ld h o ld enough wood to h e a t t h e
w a te r i n t h e s t o r a g e u n i t IOO0 F .
As a r e s u l t , o n ly one
l o a d i n g and f i r i n g w ould b e n e c e s s a r y f o r a day and a h a l f
o f h e a t f o r th e h o u se .
The f o l l o w i n g fo r m u la vvas d e v e lo p e d
to f in d th e s iz e o f th e f i r e box.
B t u ^ o t i Cl
Vf b - T O ( H ) ( E )
w h e re :
= volum e o f t h e f i r e box i n c u b ic f e e t
j = num ber o f B t u 1s p e r I o ad
w e ig h t o f L o d g ep o le p e r c u b ic f o o t (24
lbs/ft
H - num ber o I B t u 1s o f b o a t i n a pound o f d ry
wood (8 6 0 0 B t u / l b )
E - estim ated efficiency
o I' t h e bo i I o r
( .50)
—3 2 -
I n o r d e r t o f i n d t h e num ber o f B t u ' s p e r l o a d n e e d e d
t o h e a t t h e w a te r i n t h e s t o r a g e u n i t
c a l c u l a t i o n w as u s e d .
100
d e g r e e s , a s im p le
The t e m p e r a t u r e d i f f e r e n c e (IOO 0 F )
i s m u l t i p l i e d b y t h e num ber o f p o u n d s o f w a te r i n t h e ta n k
(1 5 0 0 g a l l o n s a t 8 . 3 p o u n d s p e r g a l l o n = 1 2 ,4 5 0 p o u n d s ) ,
o
T h e r e f o r e 100 F m u l t i p l i e d b y 1 2 ,4 5 0 w i l l e q u a l 1 ,2 4 5 ,0 0 0
B tu ' s in s to ra g e .
T h is f i g u r e w as u s e d i n t h e f o r m u la a s
t h e num ber o f B t u 's p e r l o a d .
U s in g t h e f o r m u la f o r t h e volum e o f t h e f i r e b o x , i t s
d im e n s io n s w e re c a l c u l a t e d :
Vf b = (2 4 ) (8 6 0 0 ) ( . 5 0 )
= 1 2 .0 6 3 9 c u b ic f e e t
B e c a u se s h e e t s t e e l i s o b t a i n a b l e i n v a r y i n g l e n g t h s
a n d w id th s o f f o u r f e e t , i t
w ith l e s s w a s te .
c o u ld b e made f o u r f e e t lo n g
The f i n a l d im e n s io n s o f t h e f i r e b o x w ere
t h e n c a l c u l a t e d t o b e 27 i n c h e s h ig h b y 22 i n c h e s w id e by
46 i n c h e s l o n g , g i v i n g a t o t a l volum e o f 1 5 .8 c u b ic f e e t .
When s p l i t wood i s
s t a c k e d , t h e r e i s a c t u a l l y o n ly 80%
a c t u a l wood i n t h e t o t a l volum e due t o t h e a i r s p a c e s .
E ig h t y
p e r c e n t o f 1 5 .8 i s 1 2 .6 4 c u b ic f e e t o f a c t u a l wood i n t h e
f i r e box.
B u rn in g t h i s am ount o f wood S h o u ld p ro d u c e t h e
n e c e s s a r y B t u 's t o r a i s e t h e w a te r i n t h e h e a t s t o r a g e u n i t
100
d e g re e s.
-3 3 -
A f t e r t h e s i z e o f t h e f i r e b o x w as c a l c u l a t e d , i t was
n e c e s s a r y t o f i n d t h e am ount o f h e a t a b s o r p t i o n a r e a n e e d e d
t o t r a n s f e r t h e h e a t fro m t h e b u r n i n g wood t o t h e w a te r f o r
h e a t s t o r a g e an d d i s t r i b u t i o n .
The f o l l o w i n g f o r m u la was
used f o r t h i s c a lc u la tio n :
( H ) B tu /h r
A
-
P
_________ ______
w h e re :
A = s u r f a c e a r e a e x p o se d t o h e a t t r a n s f e r i n
squ. f t .
K = c o n s t a n t f o r h e a t t r a n s f e r th r o u g h 1 /4 "
h o t r o l l e d s t e e l ( 3 3 ,4 7 5 )
B t u / h r = t o t a l num ber o f B t u 1s a v a i l a b l e i n
one l o a d i n g o f t h e f i r e b o x d i v id e d
by an e s t i m a t e d tim e f o r t h e com­
b u s t i o n o f t h e wood (7 h r s . )
H = a f a c t o r f o r c o n v e rtin g th e a re a o f
P
a b s o r p t i o n t o b o i l e r h o rs e p o w e r ( 1 0 )
so :
A = ^ 1 3 ^ - 4 V§7 ,8 5 7 ‘) = 5 3 .1 3 s q u a r e f e e t
The o r i g i n a l d e s ig n f o r t h e b o i l e r was a s im p le c y l i n ­
d er in s id e a la r g e r c y lin d e r.
H ow ever, i t w as fo u n d t h a t
t h i s d e s i g n d i d n o t h a v e enough s u r f a c e a r e a f o r h e a t a b s o r p ­
tio n .
As a r e s u l t , a d e s ig n w as u s e d t h a t i n c o r p o r a t e d f i r e
t u b e s t h a t w o u ld g r e a t l y i n c r e a s e t h e a r e a f o r h e a t t r a n s f e r .
T a b le 9 , p . 3 4 , l i s t ' s t h e s i z e s o f a r e a s o f t h e b o i l e r t h a t
a re s u b je c t to h e a t t r a n s f e r .
—3 4 -
TABLE 9
AREA OF HEAT ABSORPTION IN THE BOILER
P a rt
D im e n s io n s
2 1
Top ( f i r e b o x )
S id e s ( f i r e b o x )
B ack ( f i r e b o x )
F ir e tu b e s
%
4
A re a
'
8
s q .f t
16
4
( 2 ' x 4 ' )2
2 ' x 2 '
( 3 " d ia .,3 3 " lo n g ) 1 8
" ■
"
3 8 .8 8 "
TOTAL
6 6 .8 8
The f i r e
t u b e s a r e m o u n ted h o r i z o n t a l l y above t h e f i r e
b o x so t h a t t h e b u r n i n g g a s e s p a s s o u t t h e b a c k o f t h e f i r e
b o x an d e n t e r t h e f i r e t u b e s ( r e f e r t o f i g u r e I , p » 3 5 ) .
The g a s e s t h e n move f o r w a r d t h r o u g h t h e f i r e t u b e s and up
th e f lu e a t th e f r o n t o f th e b o i l e r .
The c o m p le te f i r e b o x
( e x c l u d i n g t h e d o o r) i s j a c k e t e d w i t h w a te r an d i n a d d i t i o n ,
a w a te r r e s e r v o i r s u r r o u n d s t h e f i r e t u b e s .
i n le t s a re f i t t e d
T h re e o n e - in c h
a t t h e b a s e o f t h e b o i l e r f o r c o o l w a te r
r e t u r n i n g fro m t h e h e a t s t o r a g e u n i t and one t h r e e - i n c h o u t ­
l e t a t t h e to p o f t h e b o i l e r n e a r t h e f l u e f o r w a te r .c o n v e r t ­
in g to th e h e a t s to ra g e u n i t .
A c c e s s d o o rs w e re p r o v i d e d t o t h e e n d s o f t h e f i r e t u b e s
due t o t h e f a c t t h a t t h e y a r e s u b j e c t t o s o o t i n g w h ic h r e ­
duces th e e f f ic ie n c y o f h e a t t r a n s f e r .
I t i s a s im p le
flu e
o u t l e t ( w a te r )
fire
c le a n -o u t
door
tu b e s
c le a n - o u t
door
w a te r j a c k e t
lo a d in g
door
f i r e box
i n l e t ( w a te r )
in le t
(w a te r)
fire b ric k
FIGURE I .
F i r e tu b e b o i l e r ( s i d e v ie w ) .
-3 6 -
m a t t e r t o rem ove one o f t h e s e d o o rs and r u n a c l e a n i n g r o d
down t h e t u b e s t o rem ove t h e s o o t .
When u s i n g h o t r o l l e d s t e e l t h a t w i l l b e e x p o s e d to
h i g h h e a t , t h e r e i s a p o s s i b i l i t y o f w a r p in g .
To a l l e v i a t e
t h i s p ro b le m i n t h e c l e a n - o u t d o o r s , a l i n i n g o f 3 /8 " a s ­
b e s t o s s h e e t , f o u r l a y e r s t h i c k , w as i n s t a l l e d t o i n s u l a t e
t h e s h e e t m e ta l fro m t h e h e a t .
T h ese d o o rs an d t h e f i r e
b o x d o o r w ere a l s o r e i n f o r c e d a ro u n d t h e p e r i p h e r y w ith
a n g le i r o n .
T h is c r e a t e s a h e a v y b u t v e r y s t a b l e u n i t .
HEAT CIRCULATION AND DISTRIBUTION
B a s i c a l l y , t h e r e a r e two c i r c u i t s i n t h e c i r c u l a t i n g
s y s te m .
age u n i t .
One c i r c u i t c o n n e c ts t h e b o i l e r t o t h e h e a t s t o r ­
The o t h e r c i r c u i t c o n n e c ts t h e h e a t s t o r a g e u n i t
t o t h e r a d i a t o r s t h a t t r a n s f e r t h e h e a t fro m t h e w a te r t o
th e a i r t h a t h e a ts th e h ouse ( r e f e r to f ig u r e 2 , p . 3 7 ).
The b o i l e r t o h e a t s t o r a g e u n i t c i r c u i t i s s im p le i n
d e s ig n .
I t c o n s i s t s o f one t h r e e - i n c h l i n e t h a t c o n n e c ts
t h e b o tto m o f t h e h e a t s t o r a g e u n i t t o t h e b o tto m o f t h e
b o ile r.
The o t h e r t h r e e - i n c h l i n e c o n n e c ts t h e t o p o f t h e
b o i l e r t o t h e to p o f t h e h e a t s t o r a g e u n i t .
T h re e -in c h
p lu m b in g w as u s e d t o a ll o w a l a r g e volum e t o f lo w and t h e r e
a r e no v a l v e s o r pumps i n t h e c i r c u i t .
The p r i n c i p l e o f
f i n tu b e r a d i a t o r s
c i r c u i t c o n tr o l v a lv e s
h e a t s to ra g e u n it
h o t w a te r
sy s te m f i l l v a lv e
h o t w a te r
c irc u la tio n
pump
c o ld
w a te r
re tu rn
b o ile r
c o ld
w a te r
e x p a n s io n ta n k
FIGURE 2 .
H e a tin g sy s te m s c h e m a tic .
-3 8 -
c o n v e c ti o n ( h o t w a t e r , b e in g l e s s d e n s e and l i g h t e r , r i s e s )
i s u s e d t o t r a n s f e r w a te r fro m t h e b o i l e r t o t h e h e a t s t o r ­
age u n i t .
A pump o r v a l v e i n s t a l l e d i n t h e c i r c u i t c o u ld
c au se a c o n s t r i c t i o n i n th e l i n e th ro u g h l o s s o f e l e c t r i c i t y
t o t h e pump o r i n a d v e r t e n t c l o s i n g o f t h e v a lv e =
T h is con­
s t r i c t i o n w o u ld a ll o w ste a m t o b e p ro d u c e d i n t h e b o i l e r an d
c r e a t e t h e p o s s i b i l i t y o f i n c r e a s e d p r e s s u r e w h ic h t h e
sy s te m c o u ld n o t h a n d l e .
The o t h e r c i r c u i t i s u s e d t o t r a n s f e r h o t w a te r t o t h e
r a d i a t o r s fro m t h e h e a t s t o r a g e u n i t .
I t c o n s is ts o f a
l a r g e l i n e t h a t i s p lu m b ed t o t h e t o p o f t h e h e a t s t o r a g e
u n i t t o p i c k up h o t w a te r f o r t h e r a d i a t o r s y s te m .
l i n e i s d iv id e d i n t o
T h is
s e p a r a t e c i r c u i t s a t a m a n if o ld t h a t
d i s t r i b u t e s t h e h o t w a te r t o d i f f e r e n t a r e a s o f t h e h o u s e .
T h e re a r e t h r e e s u b - c i r c u i t s , one g o in g t o t h e f a m i l y room
an d u t i l i t y ro o m , one g o in g t o t h e l i v i n g room , an d one h e a t ­
i n g t h e m a s te r b a th ro o m .
E ac h o f t h e s e c i r c u i t s i s f i t t e d
w i t h a v a l v e t h a t a d j u s t s t h e f lo w t o e a c h c i r c u i t .
The
s u b - c i r c u i t u s e d t o h e a t t h e l i v i n g room a l s o p a s s e s th r o u g h
a c o il i n s t a l l e d i n a c o n c re te s la b in th e f l o o r o f th e
e n tr y w a y .
The r a d i a t o r s u s e d i n t h e s e s u b - c i r c u i t s a r e c o n v e n ­
tio n a l f i n tu b e s ,
suspended j u s t u n d er th e f l o o r j o i s t s .
-3 9 -
T hey a r e d e s ig n e d t o h e a t t h e f l o o r o f t h e room a b o v e .
The r e t u r n l i n e fro m t h e s e s u b - c i r c u i t s t h e n c o n n e c ts
t o a n o th e r m a n if o ld t h a t i s c o n n e c te d t o t h e b o tto m o f .
th e h e a t s to ra g e u n i t .
A h o t w a te r c i r c u l a t i n g pump w as f i t t e d b e tw e e n t h e
m a n if o ld a n d t h e h e a t s t o r a g e u n i t a n d t h e n w ir e d t o a
th e rm o s ta t in th e h o u se .
As t h e h o u s e c o o ls o f f , t h e pump
c i r c u l a t e s w a te r t o t h e r a d i a t o r s r a i s i n g t h e a i r te m p e r a t u r e i n t h e h o u s e , an d s h u t s o f f when t h e a i r i n t h e h o u se
r e a c h e s t h e p r e - s e t t e m p e r a t u r e on t h e t h e r m o s t a t .
The i n l e t a n d o u t l e t o f h e a t c i r c u l a t i o n c i r c u i t and
b o i l e r c i r c u i t a r e plu m b ed t o t h e s t o r a g e t a n k i n su c h a
way t h a t t h e w a te r i n t h e h e a t s t o r a g e t a n k c a n b e som ewhat
is o la te d .
T h is may b e d e s i r a b l e i f t h e w a te r i n t h e s t o r a g e
u n i t i s c o ld a n d t h e r e i s a demand f o r h e a t i n t h e h o u s e .
A fire
c a n b e b u i l t i n t h e b o i l e r a n d t h e h o t w a te r w i l l
p a s s i n t o t h e t a n k and d i r e c t l y i n t o t h e h e a t d i s t r i b u t i o n
sy s te m f o r q u ic k h e a t i n t h e h o u s e .
The w a te r p r e s s u r e i n t h e w h o le sy s te m i s r e g u l a t e d
b y t h r e e m e a n s.
F irs t,
w h ic h s e r v e s t o f i l l
a p r e s s u r e r e d u c e r v a lv e w as f i t t e d
t h e sy s te m w i t h w a t e r .
T h is v a lv e
i s o l a t e s t h e d o m e s tic w a te r fro m t h e w a te r i n t h e h e a t i n g
sy s te m a n d m a i n t a i n s t h e p r e s s u r e i n t h e h e a t i i i g sy s te m a t
—4 0 —
about s ix p o unds.
As t h e p r e s s u r e i n t h e h e a t i n g sy ste m
d r o p s b e lo w t h i s p r e - s e t p r e s s u r e , t h e r e d u c e r v a lv e a llo w s
w a t e r t o f lo w fro m t h e d o m e s tic w a te r s u p p ly t o t h e h e a t i n g
s y s te m u n t i l i t r e t u r n s t o p r e s s u r e .
A s e c o n d m eans o f l i m i t i n g t h e p r e s s u r e i n t h e h e a t i n g
sy s te m i s t h e u s e o f a n e x p a n s io n t a n k .
s y s te m g e t s h o t t e r , i t
As t h e w a te r i n t h e
e x p a n d s an d t h e e x p a n s io n t a n k p r o ­
v i d e s a p l a c e f o r t h i s e x t r a volum e w i t h o u t i n c r e a s i n g t h e
p r e s s u r e ab o v e a s a f e l i m i t .
The e x p a n s io n t a n k i s b a s i c ­
a l l y a n a i r c u s h io n i n t h e s y s te m ; a s t h e w a te r e x p a n d s , i t
b e g in s f i l l i n g
in th e ta n k .
t h e e x p a n s io n t a n k t h u s c o m p re s s in g t h e a i r
The s i z e o f t h e e x p a n s io n ta n k w as com puted
b y f i n d i n g t h e e x p a n s io n o f t h e volum e o f w a te r u s e d i n t h e
s y s te m .
W ith a t e m p e r a t u r e i n c r e a s e o f 15 0 °F (5 0 ° F in c o m in g
w a t e r , t o a h i g h o f 200°F w a te r t e m p e r a t u r e i n t h e sy ste m
a f t e r h e a t i n g ) , t h e w a te r w as f o u n d t o e x p an d i n volum e by
38
5 6 .9 6 g a l l o n s .
B e c a u se t h e sy s te m c o u ld n o t t o l e r a t e a
s u b s t a n t i a l i n c r e a s e i n p r e s s u r e , a 160 g a l l o n e x p a n s io n
t a n k w as u s e d .
tem
6 -8
T h is w i l l i n c r e a s e t h e p r e s s u r e i n t h e s y s ­
p o u n d s w h ic h i s w i t h i n t h e p r e s s u r e l i m i t s o f t h e
s y s te m .
^ ^ L o u is A l l e n H a rd in g and A r th u r C u t t s W i l l a r d , H e a tin g
V e n t i l a t i o n a n d A ir C o n d i ti o n i n g (L ondon:
Chapman an d H a l l ,
1 9 3 7 ), p . 20.
-4 1 -
I f t h e p r e s s u r e s h o u ld i n c r e a s e t o a p o i n t t h a t t h r e a t
e n s t h e c o m p o n e n ts o f t h e s y s te m , a p r e s s u r e r e l i e f v a lv e
w i l l o p en a n d a ll o w t h e p r e s s u r e t o d r o p .
T h is v a lv e i s
p lu m b ed i n t o t h e t o p o f t h e ta n k an d i s f i t t e d w ith a b l e e d o f f l in e to a d ra in .
CHAPTER IV
PRESENTATION OF DATA
INTRODUCTION
The p u r p o s e o f e v a l u a t i n g t h e wood h e a t i n g sy s te m was
t o d e te r m in e i t s
e f f i c i e n c y w ith r e s p e c t t o wood consum p­
t i o n a n d t o com pare i t t o a c o n v e n tio n a l, e l e c t r i c a l h e a t i n g
s y s te m .
I n o r d e r t o p e rf o r m t h i s e v a l u a t i o n , a num ber o f
v a r i a b l e s w e re s t u d i e d .
F i r s t , t h e am ount o f h e a t l o s s th r o u g h t h e b u i l d i n g
m a t e r i a l s f o r e a c h week w as c a l c u l a t e d .
Then t h e am ount o f
e n e r g y t h a t w as u s e d d u r in g e a c h week was t o t a l e d .
From
t h i s , t h e e f f i c i e n c y o f t h e wood h e a t i n g sy s te m c o u ld b e
c a l c u l a t e d and a c o m p a ris o n t o e l e c t r i c a l h e a t i n g m ade.
P r im a r y i n t e r e s t w as f o c u s e d on how much h e a t was
r e a l i z e d b y t h e am ount o f wood o r e l e c t r i c i t y t h a t was
used.
BUILDING HEAT LOSS CALCULATION
The p r o c e s s d e v e lo p e d b y t h e r e s e a r c h e r t o f i n d t h e
am ount o f e n e rg y consum ed e a c h week was a s f o l l o w s :
A v e ra g e t e m p e r a t u r e d i f f e r e n c e ( i n s i d e t o o u t s i d e )
p e r day X b u i l d i n g h e a t l o s s c o e f f i c i e n t p e r h o u r
X 24 h o u r s X 5 d a y s = T o t a l H e a t L o ss P e r T e s t P e r i o d
-4 3 -
The a v e r a g e t e m p e r a t u r e d i f f e r e n c e f o r e a c h day was
fo u n d b y a v e r a g i n g t h e t e m p e r a t u r e s r e c o r d e d b y th e rm o ­
g r a p h s a t e a c h h o u r and t h e n s u b t r a c t i n g t h e o u t s i d e r e a d ­
i n g s fro m t h e i n s i d e r e a d i n g s .
The t e m p e r a t u r e s w ere r e ­
c o rd e d i n d e g r e e s C e l s i u s and c o n v e r te d t o d e g r e e s F a r e n h e i t ,
a s c u r r e n t m e th o d s u s e t h e l a t t e r f o r c a l c u l a t i o n .
T a b le 1 0 ,
p a g e 44 , i s a l i s t i n g o f t h e t e m p e r a t u r e d i f f e r e n c e f o r e a c h
day o f t h e week d u r in g t h e s tu d y p e r i o d .
T h is a v e ra g e
t e m p e r a t u r e d i f f e r e n c e f o r e a c h h o u r o f t h e day w as th e n
m u ltip lie d by th e h e a t l o s s c o e f f i c i e n t s f o r th e b u ild in g
s y s te m s i n t h e h o u s e an d t h e n m u l t i p l i e d by 24 t o f i n d t h e
h e a t lo s s f o r t h a t day.
T h ese h e a t l o s s e s w ere t o t a l e d to
f i n d th e h e a t l o s s f o r th e f i v e days u n d er s tu d y .
The f i v e
d ay p e r i o d w as u s e d t o a llo w two d a y s b e tw e e n r u n s f o r tim e
t o s w itc h fro m one h e a t s o u r c e t o t h e o t h e r .
I t i s r e v e a l e d i n T a b le 1 0 , p a g e 44, t h a t t h e w e a th e r
w as r e a s o n a b l y u n ifo rm t h r o u g h o u t t h e f i v e week t e s t p e r i o d .
D u rin g t h e w eeks i n w h ic h wood w as u s e d a s a h e a t s o u r c e ,
t h e t e m p e r a t u r e s w ere s l i g h t l y lo w e r t h u s c r e a t i n g a h i g h e r
h e a t l o s s in th e h o u se .
T h ese f i g u r e s show t h e h e a t l o s s fro m t h e h o u s e o n ly
an d do n o t a c c o u n t f o r h e a t l o s s i n t h e b a se m e n t o r th r o u g h
th e f l o o r .
T h ese a d d i t i o n a l h e a t l o s s f i g u r e s w e re ad d ed
TABLE .10
DAILY AVERAGE TEMPERATURE DIFFERENCE AND HEAT LOSS' IN GROUND FLOOR OF HOUSE
D a te
Wood
H eat
D a te
24 H r.
A v e. Temp .
H eat
D i f f . ( F 0 ) L o s s B tu
D a te
24 H r.
A ve. Temp. H e a t
D i f L (F°> L o s s B tu
3 /2 0
21
22
3 1 .1 7
3 1 .5 2
3 3 .8 2
2 6 0 ,8 6 4 .4
2 6 3 ,7 9 3 .6
2 8 3 ,0 4 2 .5 6
4 /3
4
5
3 5 .5 5
2 6 .4 5
3 1 .0 9
2 9 7 .5 1 9 .3 6
2 2 1 ,3 6 1 .1 2
2 6 0 ,1 9 3 .3 6
4 /1 6
17
18
2 9 .3 4
3 5 .0 5
2 9 .6 3
2 4 5 ,5 4 9 .7 6
2 9 3 ,3 3 7 .3 6
2 4 7 ,9 7 6 .8 8
23
24
3 4 .9 7
3 2 .9 6
2 9 2 ,6 6 7 .0 4
2 7 5 ,8 4 5 .2
6
7
3 5 .4 0
2 9 6 ,2 6 3 .9 2
3 1 5 ,5 1 2 .8 8
19
20
2 4 .3 3
2 0 3 ,6 2 0 .5 6
2 1 7 ,8 2 6 .4
E l e c t r i c a l 3 /2 7
H eat
24 H r.
A v e. Temp.
H eat
D i f f . ( F ° ) L o s s B tu
28
29
30
31
TOTAL
1 ,3 7 6 ,2 1 2 .8
2 8 .4 9
2 8 .0 6
2 5 .0 7
2 3 8 ,4 3 4 .0
2 3 4 ,8 3 5 .2
2 1 .2 4
2 3 .5 9
TOTAL
2 0 9 ,8 1 1 ,8 4
1 7 7 ,7 5 8 .4
1 9 7 ,4 2 5 .4 4
1 ,0 5 8 ,2 6 4 .8
3 7 .7 0
TOTAL
L39 0 ,8 5 0 .5
3 /1 0
2 6 .3 2
2 2 0 ,2 7 3 .2
11
12
3 0 .6 7
3 5 .1 7
2 5 6 ,6 7 8 .5 6
2 9 4 ,3 3 9 .1 2
13
14
3 2 .7 1
2 9 .4 7
2 7 3 ,7 5 1 .2
2 4 6 ,6 3 5 .5 2
TOTAL
I ,2 9 1 ,6 7 7 .6
2 6 .0 3
TOTAL 1 £ 0 8 ,3 1 0 .9
-4 5 -
t o t h e t o t a l f o r e a c h w eek a s t h e c o n d i t i o n s i n t h e h o u se
changed w ith each s h i f t i n th e h e a t s o u rc e .
D u rin g t h e
w eek s i n w h ic h e l e c t r i c i t y w as u s e d t o h e a t t h e h o u s e , t h e
b a s e m e n t w as n o t h e a t e d and t h e h e a t l o s s th r o u g h t h e
f l o o r w as a d d e d t o t h e t o t a l l o s s t h r o u g h t h e r e s t o f t h e
hou se.
The b a se m e n t w as c o n s i d e r e d t o h a v e a te m p e r a t u r e
e q u a l t o t h a t o f t h e s u r r o u n d in g g ro u n d (4 5 ° F ) and t h e
t e m p e r a t u r e d i f f e r e n t i a l w as d e te r m in e d u s i n g t h e h e a t l o s s
c o e f f i c i e n t o f t h e f l o o r i n g sy s te m and a t e m p e r a t u r e d i f ­
f e r e n c e o f 25°F (7 0 °F - 4 5 °F ) .
D u rin g t h e w eeks i n w h ic h wood was u s e d a s a h e a t
s o u r c e , t h e b a s e m e n t w as h e a t e d a lo n g w ith t h e h o u s e .
T h is
w as due t o t h e f a c t t h a t r a d i a t o r s f o r t h e h o t w a te r sy ste m
w e re s u s p e n d e d fro m t h e f l o o r j o i s t s and t h e r e w as no i n s u l ­
a t i o n u n d e r them t o i s o l a t e t h e h e a t and f o r c e i t t o con­
d u c t th ro u g h th e f l o o r .
As a r e s u l t ,
t h e h e a t l o s s th r o u g h
t h e u n i n s u l a t e d c o n c r e t e w a l l s w as ad d ed t o t h e h e a t l o s s
in th e h o u s e .
T h is h e a t l o s s i s c o n s i d e r a b l e i n c o m p a ris o n
t o t h e t o t a l l o s s fro m t h e h o u s e , a s n o t e d i n T a b le 1 1 , p . 46
-4 6 -
TABLE 11
TOTAL HEAT LOSS PER WEEK, HOUSE AND FLOOR OR BASEMENT
H eat L o ss
H ouse
B tu /w k
Week
M ar. 2 0 -2 4
M a r. 2 7 -3 1
A p r. 3 -7
A p r. 1 0 -1 4
A p r. 1 6 -2 0
H e a t L o ss
F l o o r o r B asem ent
B tu /w k
1 ,3 7 6 ,2 1 2 .8
1 ,0 5 8 ,2 6 4 .8
1 ,3 9 0 ,8 5 0 .6
1 ,2 9 1 ,6 7 7 .6
1 ,2 0 8 ,3 0 8 .8
4 ,8 2 1 ,3 3 6 .0
2 2 ,4 1 2 .6 5
4 ,8 2 1 ,3 3 6 .0
2 2 ,4 1 2 = 6 5
4 ,8 2 1 ,3 3 6 .0
T o ta l
6 ,1 9 7 ,5 4 8 .8
1 ,0 8 0 ,6 7 7 .4
6 ,2 1 2 ,1 8 6 .6
1 ,3 1 4 ,0 9 0 .2
6 ,0 2 9 ,6 4 4 .8
The t o t a l h e a t l o s s f o r e a c h week c a n t h e n b e com pared
w i t h t h e am ount o f e n e r g y u s e d t h a t week t o show t h e e f f i ­
c ie n c y o f t h e h e a t i n g s y s te m .
ENERGY USE CALCULATION
The am ount o f e l e c t r i c i t y u s e d d u r i n g .e a c h week t h a t
t h e e l e c t r i c b a s e b o a r d h e a t e r s w e re u s e d t o h e a t t h e h o u se
i s a s im p le c a l c u l a t i o n .
The k i l o w a t t h o u r m e te r i s o l a t i n g
t h e e l e c t r i c b a s e b o a r d h e a t e r s w as r e a d a t t h e b e g in n in g
an d e n d o f e a c h w eek .
The d i f f e r e n c e i n r e a d i n g s from
39
b e g in n i n g t o e n d w as t h e n . m u l t i p l i e d b y 3 ,4 1 3 ■ t o g iv e
t h e num ber o f B t u ' s i n e l e c t r i c a l e n e rg y u s e d t h a t w eek.
T h e se t o t a l s a r e shown i n T a b le 1 2 , p a g e 47.
39'
C o n k lin , p . 1 6 7 .
-4 7 -
The am ount o f e n e rg y u s e d d u r i n g t h e w eeks t h a t t h e
w o o d - f i r e d b o i l e r w as u s e d t o h e a t t h e h o u s e w as fo u n d by
w e ig h in g a l l t h e wood u s e d t h a t w eek.
B e c a u se a l l wood
h a s 8 ,6 0 0 B t u ' s p e r pound ( w i t h t h e e x c e p ti o n o f h i g h l y
r e s i n o u s w o o d ), t h e t o t a l w e ig h t o f wood consum ed c o u ld b e
c o n v e r t e d i n t o B t u 1s u s e d t h a t w eek.
T h ese t o t a l s a r e
a l s o p r e s e n t e d i n T a b le 1 2 .
TABLE 12
TOTAL HEAT LOSS VERSUS ENERGY USED
T o ta l
H e a t L o ss
(B tu /w k )
Week
M ar. 2 0 -2 4
M ar. 2 7 -3 1
A p r. 3 -7
A p r . 1 0 -1 4
A p r. 1 6 -2 0
6 ,1 9 7 ,5 4 8 .8
1 ,0 8 0 ,6 7 7 .4
6 ,2 1 2 ,1 8 6 .6
1 ,3 1 4 ,0 9 0 .2
6 ,0 2 9 ,6 4 4 .8
Wood
Am t.
E n e rg y
U sed
U sed
(B tu )
(lb s )
894
902
976
E le c tric ity
Am t. . E n e rg y
U sed
U sed
(B tu )
(kw h)
7 ,6 8 8 ,4 0 0
228
7 7 8 ,1 6 4
275
9 3 8 ,5 7 5
7 ,7 5 7 ,2 0 0
8 ,3 9 3 ,6 0 0
D u rin g t h e w eeks o f M arch 2 7 -3 1 a n d A p r i l 10--14 when
t h e e l e c t r i c a l sy s te m w as i n u s e , t h e am ount o f e l e c t r i c i t y
n e e d e d i n B t u 's was l e s s t h a n w h at w as a c t u a l l y l o s t i n
th e h o u se .
100%
The e l e c t r i c r e s i s t a n c e ty p e h e a t e r s u s e d a r e
e f f i c i e n t an d no a c c o u n t was made f o r o t h e r s o u r c e s o f
h e a t su c h a s su n i n f i l t r a t i o n
an d c o o k in g .
The su n
—4 8 -
i n f i l t r a t i o n on an u n c u r t a i n e d window c a n b e a s i g n i f i c a n t
c o n trib u to r. ^
I t s h o u ld a l s o b e n o t e d t h a t t h e e n e r g y - u s e d c a l c u l a ­
t i o n s do i n c l u d e t h e tw o d a y s b e tw e e n t h e t e s t i n g p e r i o d
w h ile t h e t o t a l h e a t l o s s i s o n ly c a l c u l a t e d on t h e f i v e
d ay t e s t i n g p e r i o d .
T h is o c c u r r e d b e c a u s e t h e r e w as con­
s i d e r a b l e o v e r l a p on t h e h e a t i n g s o u r c e s due t o t h e f a c t
t h a t i t w as d i f f i c u l t t o s t a r t an d s t o p e a c h sy s te m a b r u p t l y
T h e re w as a l s o c o n s i d e r a b l e r e s i d u a l , h e a t l e f t i n t h e h o u se
a t t h e e n d o f a t e s t p e r i o d t h a t w o u ld b e i n c l u d e d i n t h e
n e x t t e s t p e rio d .
H ow ever, t h e s e f i g u r e s a r e u s e d i n a
c o m p a r a tiv e s e n s e an d s h o u ld n o t a f f e c t t h e r e s u l t s b e c a u s e
t h e same m eth o d w as u s e d f o r e a c h e n e rg y s o u r c e p e r i o d .
BOILER EFFICIENCY
The e f f i c i e n c y o f t h e b o i l e r i n t h e num ber o f B t u 's
t h a t i t c a n e x t r a c t fro m t h e b u r n i n g wood v e r s u s t h e p o te n ­
t i a l num ber o f B t u 's t h a t a r e a v a i l a b l e i n t h e wood c a n b e
c a l c u l a t e d fro m t h e d a t a i n T a b le 1 2 , p a g e 47.
p.
49
T a b le 1 3 ,
, p r e s e n ts th e a p p ro p r ia te d a ta d e s c rib in g th e e f f i ­
c ie n c y o f t h e wood f i r e d b o i l e r .
^ C o n k lin , p . 34.
-4 9 -
TABLE 13
EFFICIENCY IN PERCENT OF THE WOOD-FIRED BOILER
T o ta l H eat
R e c o rd e d
i n H ouse
(B tu )
% H eat
P o te n tia l
H eat o f
C o n trib u te d
Wood U sed
b y O th e r
(B tu )
S o u rc e s (B tu )
1 8 ,4 3 9 ,3 7 9
2 3 ,8 3 9 ,2 0 0
2 8 .3 1
T o ta l H eat
E x tra c te d
by
B o ile r(B tu )
E ffic ie n c y
of
B o ile r
(%)
1 3 ,2 1 9 ,1 9 1 .0
53%
D a ta i n T a b le 13 r e v e a l t h e t o t a l h e a t r e c o r d e d i n t h e
h o u s e i s an a d d i t i o n o f t h e h e a t l o s s e s i n t h e h o u s e f o r
t h e t h r e e w eeks t h a t wood w as u s e d a s t h e h e a t s o u r c e .
The
p o t e n t i a l num ber o f B t u 1s a v a i l a b l e i n t h e wood w as fo u n d
b y a d d in g t h e p o u n d s o f wood u s e d f o r t h e t h r e e w eeks and
t h e n m u l t i p l y i n g b y t h e num ber o f B t u 's i n a p o u n d o f wood.
B e c a u se t h e r e w e re o t h e r c o n t r i b u t o r s o f h e a t d u r in g
t h e t e s t p e r i o d su c h a s su n i n f i l t r a t i o n ,
c o o k in g , and h e a t
fro m p e o p le i n t h e h o u s e , o n ly p a r t o f t h e t o t a l h e a t l o s s
r e c o r d e d i n t h e h o u s e w as c o n t r i b u t e d by t h e wood h e a t i n g
s y s te m .
Due t o t h e f a c t t h a t t h e e l e c t r i c a l r e s i s t a n c e
h e a t e r i s 100% e f f i c i e n t ,
t h e a d d i t i o n a l am ount o f B t u 's
r e c o r d e d i n t h e h o u s e d u r i n g t h e t e s t p e r i o d s w h ic h u s e d
e l e c t r i c i t y c a n b e u s e d t o f i n d t h e p e r c e n t a g e o f h e a t co n ­
t r ib u t e d by o th e r so u rc e s o f h e a t.
I t w as fo u n d t h a t t h e
e l e c t r i c a l h e a t e r s a c c o u n te d f o r 71.69% o f t h e t o t a l h e a t
re c o rd e d i n th e h o u se d u rin g th e e l e c t r i c a l h e a tin g t e s t
-5 0 -
p e r i o d ( 1 ,7 1 6 ,7 3 9 d i v i d e d b y 2 ,3 9 4 ,7 6 7 .6 m u l t i p l i e d b y 1 00;
d a t a fro m T a b le 1 2 , p . 4 7 ); t h e r e f o r e 28.31% w as c o n t r i b u t e d
by u n rec o rd ed h e a t s o u rc e s .
When 28.31% o f t h e h e a t r e c o r d e d i n t h e h o u s e i s su b ­
t r a c t e d fro m t h e t o t a l h e a t r e c o r d e d , t h e t o t a l h e a t r e ­
c o rd e d i n t h e h o u s e t h a t w as c o n t r i b u t e d b y t h e wood h e a t ­
i n g sy s te m i s f o u n d .
The e f f i c i e n c y c a n t h e n b e c a l c u l a t e d
u s i n g t h i s a d j u s t e d h e a t r e c o r d e d datum ( 1 3 ,2 1 9 ,1 9 1 .0
d i v i d e d b y 2 3 ,8 3 9 ,2 0 0 m u l t i p l i e d b y 1 0 0 , o r 55% b o i l e r
e ffic ie n c y ).
WOOD VS. ELECTRICITY:
COST ANALYSIS
U s in g c u r r e n t r a t e s f o r b o th e l e c t r i c i t y a n d wood, a
d i r e c t c o m p a ris o n c a n b e made o f t h e e n e rg y s o u r c e s u s e d i n
t h i s s tu d y .
T h is i n f o r m a t i o n i s sum m arized i n T a b le 1 4 ,
page 5 1 .
The am ount o f wood o r e l e c t r i c i t y u s e d an d t h e c o r r e ­
s p o n d in g num ber o f B t u 's t h a t w ere a c t u a l l y r e a l i z e d i n t h e
h e a t i n g o f t h e h o u s e a r e t a k e n fro m T a b le 1 2 , p . 47.
In th e
c a s e o f w ood, t h e t h r e e w eeks d u r i n g w h ic h woqd w as u s e d a s
t h e h e a t s o u r c e w ere a d d e d t o g e t h e r .
L ik e w is e , t h e two
w eek s d u r i n g w h ic h e l e c t r i c i t y w as u s e d a s t h e h e a t s o u rc e
w e re a d d e d .
TABLE 14
ENERGY SOURCE USE AND WOOD VS. ELECTRIC COST COMPARISON
E n e rg y S o u r c e /
Amount U sed
E le c tric ity
Wood
(k w h /B tu )
(Ih s /B tu )
2772
1 8 ,4 3 9 ,3 7 9
503
2 ,3 9 4 ,7 6 7 .6
C ost o f
E n e rg y S o u rc e
Wood
E le c tric ity
( S /lb .)
(S /k w h )
.0 1 1 4 8 8 9
.02803*
C o st C o m p ariso n
Wood
E le c tric ity
(S /m il.B tu )
( S /1 m il .B t u )
1 .7 2 7
5 .8 9
*On 503 kwh p r o - r a t e d
i
Cl
H
I
-5 2 -
The c o s t o f wood a s an e n e r g y s o u r c e i n T a b le 1 4 , p . 51
w as c a l c u l a t e d b y f i r s t f i n d i n g t h e volum e i n c u b ic f e e t i n
a c o rd o f w ood.
B e c a u se p a r t o f t h a t volum e i s due t o a i r
s p a c e s i n t h e s t a c k , 80% o f t h e t o t a l volum e w as u s e d .
T h e r e f o r e a c o r d o f 128 c u b ic f e e t ( 4 ' x 4 ' x
8
')
is .m u l­
t i p l i e d b y 80% t o f i n d t h e a c t u a l am ount o f wood i n t h e
c o rd .
T h is f i g u r e ( 1 0 2 .4 c u b ic f e e t ) i s t h e n m u l t i p l i e d b y
2 5 .5 p o u n d s p e r c u b ic f o o t t o g iv e t h e num ber o f p o u n d s i n
a c o r d o f l b d g e p o l e ( 2 6 1 1 .2 p o u n d s ) .
A t $ 3 0 .0 0 p e r c o rd
o f f ir e w o o d , t h e c o s t o f a pound o f f ir e w o o d c a n b e fo u n d
b y d i v i d i n g $ 3 0 .0 0 by 2 6 1 1 .2 p o u n d s , r e s u l t i n g i n $ 0 .0 1 1 4 8 8 9
p e r pound o f lo d g e p o le .
The c o s t o f e l e c t r i c i t y r e c o r d e d i n T a b le 1 4 , p . 51,
w as fo u n d b y u s i n g t h e t o t a l k i l o w a t t h o u r s u s e d d u r in g t h e
tw o week t e s t p e r i o d and a p p ly i n g t h i s t o t a l t o t h e c u r r e n t
ra te
s c h e d u le :
TABLE 15
SCHEDULE FOR CALCULATING COST OF ELECTRICITY USED
Kwh
f i r s t 2 0 kwh
n e x t 80 kwh
n e x t 1 0 0 kwh
an y a d d . 303 kwh
TOTAL 503 kwh
R a t e ( 0 /k w h )
.0 1 6 9
.0 5 3 8
.0 3 7 6
.0 1 8 8
C o s t( $ )
.3 3 8
4 .3 0 4
3 .7 6 0
5 .6 9 6 4
$ 1 4 .0 9 8 4
-5 3 -
T h e r e f o r e , f o r 503 k i l o w a t t h o u r s , 2 ,3 9 4 ,7 6 7 .6 B t u 1s
w e re r e a l i z e d i n t h e h o u s e and t h e y c o s t S i 4 . IQ .
The c o s t
o f SO .0 2803 p e r kwh r e p o r t e d i n t h e t a b l e i s a d i v i s i o n o f
503 kwh b y S 1 4 .0 9 8 4 t o f i n d t h e c o s t p e r k i l o w a t t h o u r f o r
t h i s s tu d y a n d i s o n ly t r u e i f 503 k i l o w a t t h o u r s a r e u s e d .
The c o s t o f e a c h e n e r g y s o u r c e i s fo u n d b y m u l t i p l y ­
in g th e c o s t o f each p e r pound o r k ilo w a tt h o u r by th e
num ber o f p o u n d s o r k i l o w a t t h o u r s u s e d .
The r e s u l t i s t h e n
d i v i d e d b y t h e num ber o f m i l l i o n B i n 's r e a l i z e d i n t h e
house in each c a s e .
T hus t h e c o s t p e r m i l l i o n B t u 1s o f wood
w as f o u n d t o b e S i . 73 a n d t h e c o s t p e r m i l l i o n B i n 's o f
e l e c t r i c i t y w as fo u n d t o b e S 5 .8 9 .
CONCLUSION
The m a jo r p u r p o s e o f t h i s c h a p t e r w as t o e v a l u a t e t h e
p e rf o r m a n c e o f t h e w o o d - f i r e d b o i l e r i n te r m s o f e f f i c i e n c y
an d t o com pare i t t o an e l e c t r i c a l h e a t i n g s y s te m . . To accom ­
p l i s h t h i s , t h e am ount o f h e a t t h a t w as r e a l i z e d i n t h e
h o u s e w as co m p ared t o t h e a c t u a l e n e rg y i n p u t t o e a c h h e a t i n g
s y s te m .
T h e se f i g u r e s w ere t h e n t r a n s l a t e d i n t o c o s t o f
e a c h e n e rg y s o u r c e t o f i n d w h e th e r a wood h e a t i n g sy ste m
w as c o m p e t i t i v e w i t h an e l e c t r i c a l h e a t i n g s y s te m .
The
e f f i c i e n c y o f t h e w o o d - f i r e d b o i l e r w as d e te r m in e d by
-5 4 -,
m e a s u r in g t h e p o t e n t i a l e n e rg y i n p u t and c o m p a rin g i t t o t h e
e n e r g y t h a t w as t r a n s f e r r e d t o t h e w a te r f o r h e a t i n g t h e
i
house.
I n summary o f t h e d a t a p r e s e n t e d i n t h i s c h a p t e r , t h e
wood h e a t i n g s y s te m p r o v id e d h e a t a t S i .7 3 p e r m i l l i o n
B t u 1 s , t h e e l e c t r i c a l h e a t i n g s y s te m p r o v i d e d h e a t a t $ 5 .8 9
p e r m i l l i o n B t u ' s and t h e b o i l e r o p e r a t e d a t an e f f i c i e n c y
o f 55%.
T h e r e f o r e , a d o l l a r ' s w o rth o f wood i s e q u a l t o
$ 3 . 4 0 1s w o rth o f e l e c t r i c i t y .
CHAPTER V
CONCLUSIONS, IMPLICATIONS, AND RECOMMENDATIONS
FOR FURTHER STUDY
CONCLUSIONS
1.
The wood h e a t i n g sy s te m p r o v i d e s h e a t f o r t h e h o u se
a t a c o s t o f S i .7 3 p e r m i l l i o n B t u 's .
2.
The e l e c t r i c a l h e a t i n g sy s te m p r o v i d e s h e a t f o r
t h e h o u s e a t a c o s t o f S 5 .8 9 p e r m i l l i o n B t u 's .
3.
The e f f i c i e n c y o f t h e b o i l e r h a s b e e n f o u n d t o
b e 55%.
IMPLICATIONS
As a r e s u l t o f t h e r e p o r t e d d a t a , t h e r e s e a r c h e r p r e ­
s e n t s t h e f o l l o w i n g i m p l i c a t i o n s 8:
1.
C e n t r a l wood h e a t i n g sy s te m v a r i a b l e c o s t s a r e
c o m p e t i t i v e w i t h c o n v e n t io n a l h e a t i n g s y s te m s .
2.
C e n t r a l wood h e a t i n g s y s te m s c a n b e b u i l t t h a t
m in im iz e hom eow ner in c o n v e n ie n c e and p r o v i d e a c o m f o r ta b le
h e a t.
3.
C e n t r a l wood h e a t i n g s y s te m s c a n b e d e s ig n e d su c h
t h a t t h e y c a n b e b u i l t b y l o c a l w e ld in g sh o p s and e q u ip p e d
t h r o u g h l o c a l s u p p ly h o u s e s .
-5 6 -
4.
C e n t r a l wood h e a t i n g sy s te m i n s t a l l a t i o n c o s t s
a r e c o m p e t i t i v e w i t h o t h e r a l t e r n a t i v e e n e rg y s y s te m s .
5.
Wood h e a t i n g s y s te m s c a n b e d e s ig n e d t o m in im iz e
t h e am ount o f a i r p o l l u t i o n p r o d u c e d .
RECOMMENDATIONS FOR FURTHER STUDY
T h ro u g h t h e d e v e lo p m e n t an d t e s t i n g o f t h e h e a t i n g
sy s te m i n t h i s s t u d y , t h e r e s e a r c h e r m akes t h e f o l l o w i n g
re c o m m e n d a tio n s f o r f u r t h e r s tu d y :
1.
The e f f i c i e n c y o f a w o o d - f i r e d b o i l e r b e s t u d i e d
u t i l i z i n g a c l o s e l y c o n t r o l l e d e n v iro n m e n t t o m in im iz e ex ­
t r a n e o u s v a r i a b l e s a n d t o e v a l u a t e t h e e f f e c t s o f te m p e ra ­
t u r e o f in c o m in g a i r , t e m p e r a t u r e o f t h e w a te r i n t h e b o i l e r ,
an d t h e e f f e c t o f f o r c e d d r a f t .
2.
S t u d i e s b e made r e g a r d i n g t h e e f f e c t s o f c o n d u c­
t i v e h e a t i n g t h r o u g h a wood f l o o r i n g sy s te m i n te r m s o f
a c t u a l h e a t t r a n s m i s s i o n an d d e t r i m e n t a l e f f e c t s t o t h e
f l o o r c o v e rin g s ( t i l e ,
5.
c a r p e t, a d h e s iv e s , e t c . ) .
S t u d i e s b e made o f w a te r t r e a t m e n t c h e m ic a ls t h a t
w o u ld m in im iz e c o r r o s i o n o f sy s te m p a r t s .
4.
The u s e o f t h e wood h e a t i n g sy s te m t o p r e h e a t t h e
d o m e s tic h o t w a t e r b e s t u d i e d .
-5 7 -
5.
The am ount a n d ty p e o f e m i t t e d c h e m ic a ls and
p a r t i c u l a t e s b e s t u d i e d i n r e l a t i o n t o t h e t e m p e r a t u r e and
am ount o f t h e in c o m in g d r a f t a i r .
APPENDIX ■
dkkcA ao__________
F ig .
Z l ____________. - 2 7
3 . T e m p e r a tu r e
G rap h f o r
2.%
____
M arch 2 0 - 2 4
2H___________
/
:
ZB
T e m p e ra tu re G raph f o r M arch 27 o l
F ig .
5.
T e m p e r a tu r e
G rap h f o r
A p r il
3 -7
Cl -
U
I
•
c 7/
F ig .
6.
T e m p e r a tu r e G rap h f o r
A p r il
1 0 -1 4
F ig . 7 .
T e m p e ra tu re G raph f o r A p r i l 1 6 -2 0
BIBLIOGRAPHY
BIBLIOGRAPHY
B ab co ck an d W ilc o x Company. S team ; I t s G e n e r a tio n and U s e .
New Y o rk : The B abcock a n d W ilc o x Company, 1 9 6 3 .
Bozeman D a i l y C h r o n i c l e , M arch I , 1 9 7 8 .
B y rn e , S t e w a r t . R e p o r t No. I ; The A rk a n s a s S t o r y .
O h io :
O w e n s-C o m in g F i b e r g l a s s C o r p ., 1 9 7 5 .
C o n k lin , G r o f f . The W e a th e r C o n d itio n e d H o u se .
R e in h o ld P u b l i s h i n g C o r p ., 1 9 5 8 .
”
de L o r e n z i , O t t o . C om bustiA h E n g i n e e r i n g .
b u s t i o n E n g in e e r i n g C o ., I n c . , 1 9 4 7 .
D u l l , C h a r le s E . M odern P h y s i c s .
an d Company, 1 9 4 5 .
“
E ck h o lm , E .P .
L o sin g , G ro u n d .
New Y ork:
New Y o rk :
New Y ork:
New Y o rk :
T o le d o ,
Com­
H enry H o lt
W.W. M o rto n , 1 9 7 6 .
G ay, L a r r y .
The C o m p lete Book o f H e a tin g w ith Wood.
l o t t e , V erm ont: G a rd en Way P u b l i s h i n g , 1 9 7 4 .
C h a r­
Hammond, A la n L„
" I n d i v i d u a l S e l f S u f f i c i e n c y i n E n e r g y ."
S c ie n c e 1 8 4 , ( A p r i l 1 9 , 1 9 7 4 ) .
H a r d in g , L o u is A l l e n , a n d W i l l a r d , A r th u r C u t t s . H e a t i n g ,
V e n t i l a t i o n an d A ir C o n d i t i o n i n g . L o n d o n : Chapman and
H a ll, 1937.
H u tc h in s o n , F.W . D e s ig n o f H e a tin g an d V e n t i l a t i n g S y s te m s .
New Y o rk : The I n d u s t r i a l P r e s s , 1 9 5 5 .
J e n n i n g s , B u rg e s s H. H e a tin g an d A ir C o n d i t i o n i n g .
I n t e r n a t i o n a l T e x tb o o k Company, 1 9 5 6 .
S c r a n to n
K o n zo , S e i c h i , C a r r o l l , J . Raym ond, a n d B a r e i t h e r D. W in te r
A ir C o n d i t i o n i n g . New Y o rk : The I n d u s t r i a l P r e s s ^
1956.
L y l e , D a v id . The L ange S to v e C a ta lo g and Wood H e a t^ G u id e .
A l s t e a d , WTHTT S c a n d in a v ia n S t o v e s , I n c . , 1 9 7 6 .
-6 6 -
M o n tan a Pow er Company, P e r s o n a l i n t e r v i e w w ith L yne M a r tin ,
M ontana Pow er R e p r e s e n t a t i v e . Bozem an, M o n ta n a . May 2 ,
1978.
S h e l t o n , J a y ¥ . W o o d tu r n e r 's E n c y c lo p e d ia .
V erm ont C r o s s r o a d s P r e s s , 1 9 7 6 .
W a its fi e l d :
T a f t , T h e o d o re H. E le m e n ta r y E n R in e e rin R T h erm o d y n am ics.
New Y o rk : J o h n W ile y an d S o n s , I n c T ,1 9 3 5 » .
U .S . D e p a rtm e n t o f A g r i c u l t u r a l , R u r a l E l e c t r i f i c a t i o n Admin­
is tra tio n .
E l e c t r i c H ouse H e a t i n g . REA B u l l e t i n 1 4 2 -1 ,
1960.
V erm o n t, S t a t e o f . R e p o r t on t h e G o v e r n o r 's T ask F o r c e on
Wood a s a S o u rc e o f E n e rg y , 1 9 7 5 .
MONTANA STATE UNIVERSITY LIBRARIES
762 10014165 2
N378
H119
c o p .2
Hegan, H. P.
Home h e a tin g u s in g a
v o id - f ir e d b o i l e r . . .
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