Performance of add-on heat pumps in various parts of Canada

(1)

Publisher’s version / Version de l'éditeur: Building Practice Note, 1981-10-01

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Performance of add-on heat pumps in various parts of Canada

Cane, R. L. D.

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(2)

Ref Sex THI

BUILDING

PRACTICE

NOTE

PERFORMANCE OF ADD-ON HEAT PUMPS

IN

VARIOUS PARTS

OF

CANADA

I

N l i .

_BLDG.

_RES:

L I B R A R Y

-

Division

of

Building Research, National Research Culirlcil of

Canada

(3)

Performance of Add-On Heat Pumps

in Various Parts of Canada by

R.L.D. Cane

INTRODUCTION

As a means o f reducing.oi1 consumption, the Governmenr of Canada has i n i t i a t e d a program that offers a grant to homeowne~s who convert their e x i s t i n g o i l heating system t o ather forms of energy such a s natural gas or

electricity. T h i s grant also applies to add-on heat pump systems, if t h i s addition reduces oil consumption to SO% of previous annual levels.

The addition of an electric heat to an exis.ting oil furnace (Figure I) w i l l , in most cases, reduce annual oil consumption by more than

50%. The actual saving i n energy costs w i l l depend on t h e amount of electricity used by the heat pump.

This Note provides the homeowner w i t l i .a meam of estimating the electricity and oil caaflunption that will result from an add-on heat pump installed on an existing o i l fhnace.

OPERATION

OF THE FURNA,CE AND HEAT PUMP

There are basically two ways that the furnace and heat pump operation are controlled on currently available add-on heat pumps. In both, the heat pump provides a l l the h e a t i n g needs of t h e home u n t i l the heat Ioss from the

house exceeds the capacity of t h e heat pump. The outdoor temperature at

which t h i s usually occurs is in t h e v i c i n i t y of 0% t o - 5 * ~ . _{This temperature}

is referred to as the balance point. I f the temperature falls below the balance point, the system operates

in

one of two ways:

(A)

-

the heat pump shuts off and the furnace provides a l l the heating; or

(B) - the furnace and heat pump share the heating duty, but never

operate siml tans-ausly

.

W i t h

either

method (A) OT (83, primary control is by a central indoor

thermostat. Additional thennostat controls located in the furnace (in case

( 8 ) ) and an outdoor thermostat [in both (A) and (B)) contra1 the operation

of the heat pump.

In

the illustsatrons included in this paper, method (A) is referred to

as "No operation below t h e balance pointt1, and method

[B]

as f'Operation below balance point". Wen estimating the potential benefit of an add-on heat

(4)

AN EXAMPLE ILLUSTRATING THE USE OF THE FIGURES

In considering an add-an heat puhp it is desirable to estimate the f u e l oil saving and electrical energy consumption associat.ed with different

s i z e s of heat pumps. Figures 2 through 9 offer a convenient way of

estimating t h e energy use for various locations in Canada. The data far these c i t i e s can be used also fur other locations in the same general c.Iimate;

zones.

The s i z e of a heat pump installed in a home is usually based on t h e

requirement for air conditioning. Manufacturers l representatives will provide

an estimate af the cooling capacity ~ e q u i r e d [expressed i n Tons) and at the

same t i m e indicate which method of control ((A] or [B]) is empl&yed t o operate the oil furnace and heat pump.'

Consider, for example, a homeowner in Ottawa who wishes to estimate the

saving in oil consumption achieved with an add-on heat pump. A heat pump contracto~ may recommend a 3-ton (10.5 kW) heat pump that is designed to

operate as outlined above for method [B). By checking heating oil b i l l s from previous years (following the addition of insulation], an average annual consumption of 800 gallons (3632 litres) is found to be typical. Referring

to Figure 7, the addition of a heat pump will ~ e s u l t in an oil consumption

of 230 gallons (1044 litres) and an e l e c t r i c i t y consumption of approximately

10,000 kW.h. The reduction in oil consumption is 70% and thus qualifies for the Govement of Canada grant.

A t current energy prices in Ottawa of 254 per litre for heating o i l and

3,12$ per kW.h far electricity, the dollar saving is calculated as follows: First year saving = (3632

-

10441 x 0.25

-

10,000 x 0,0312 = $335

Other factors affect the cost of owning and operating the add-on heat pump system, including t h e cost of service or of preventive maintenance. Most manufacturers offer a s e r v i c e contract that covers p a r t s and labour for 4 years beyond the initial 1-year warranty period, This is similar to t h e

plans offered by heating oil companies and should be investigated in t h e

case of a heat pump..

ACKNOWLEDGEMENT

The author wishes t o acknowledge the able assistance of D,R. Wright

who prepared the computer program t o produce Figures 2 through 9.

1. Cane, R.L.D., Residential Space Heating with aHeat Pump, National

Research Council of Canada, Div. Bldg. Res,, Bldg. Res. Note 125. January 1978

2. Cane, R . L . D . , The Cost of Owning and Operathg a Residential Heat

Pump System in Canada, National ~ e s e a r c h Council of Canada, Div. Bldg. Res., April 1980. NRCC 18306

(5)

ADD-ON HEAT PUMP HEAT EXCHANGER HOTVAPOUR LINE OUTDOOR S E C T I O N I N D Q O R SECTION

F I G U R E

1 A D D - O M

HEAT

P U M P

(6)

F I G U R E

2

m

8;

X--

a n

X-

m 0 0- 00

z--

t 0 0 - - PI 0 0 1 T O N = 3 . 5 k W 1 G A L . = 4 + 5 4 L

V A N C O U V E R : A D D - O N HEAT PUMP a ) W I T H NO O P E R A T I O N AND

b ) W I T H OPERATION, BELOW B A L A N C E P O I N T 0

-X

-

_-

-

--

-

8;

=--

I

8-1

0 o-- rn

8--

c

E

0 C - LEGEND

-

x = 1.5 TON

_

0 =2.0

TON

-

~ = 2 . 5 TON

-

A =

3.0

TON

-

_-

-

- 7 -

-

--

-

1-

- -

-

- -

-

- -

_-

-

_-

-

- C - 1 1 1 1 1 1 1 - I I I I I l l l l r l l l f_I l ~ l _Il Il l l

- E

7 - r

a n u

-3

o

2 -

- -

5 c

- - z

s

w

I

--

_w

E

0

1-

_B

0 ---g rn

"

Id Z

-

d

- - I

CV

E

I m u ca d D Z

8

N

W-I

w t l l l i t l l

-

U3 0 2w 400 800 BW mm 12m woo _iaoO

HISTORIC

FUEL O I L CONSUMPTION, GAL.

-

- - _-

--

-

(7)

Q 0 0

8 1

- 8

8 c..

-

n 3

-

_-

_LEGEND < z g,- x =25 TON - o x o = Z O TON

,,X

+ O

-

8 - - S

5

I- IL

= = 2 5

TON - 5

-

- A

=3.0

TON r 3 - rn

0--

Z

-

--I

z

0

-

0

-

- 0

-

0

s-1

-

--

E

Q

-

_-

-

1-

8 -

- - 0

-

a-- a _-

--

-

f*

s

-

0 1 1 1 1 1 1 1 I 1 1 i 1 I 1 1 1 l I 1 1 1 1 r 1 I l I I I I 1 I I I L I 1 o

0 MO 4Kl 600 8Q[I WOO m WOO m

HISTORIC FUEL O I L C O M W T I O N ,

GAL.

1 TON = 3 . 5 kW

1 G A L . = 4 . 5 4 L

F I G U R E 3

EDMONTON: A D D - O N HEAT PUMP a ) W I T H

N O

O P E R A T I O N A N D

(8)

1

TON = 3.5 kW 1 G A L . ' 4 . 5 4 L

1:

0 m-- 8

-

2-1

Z

-

J n + 2

$--

0 rn

-

d 4

g--

m

-

z 0

A

=

n F I G U R E 4 S A S K A T O O N : A D D - O N HEAT PUMP a1 W l T H

N O

O P E R A T I O N A N D b ) W l T H O P E R A T I O N , B E L O W B A L A N C E P O I N T -

-

_-

-

1-

L

-

_-

C

-

_-

-

- - 1 1 1 1 1 1 1 1~ 1 1 1 1 1 1 1 1 1 1 1 l l l l l f 1 1 1 1 1 1 , , 1 - I 1 I I I I I

- 3

c

1-

s"

0

1-

f

0

$

- - O A

_ g m

W z 2

1-1

:

f 1/1 u 0 0

-

Z 1

=

3:

+

-

3 z o--

o

5 -

c a ZE

8-1

Z 0 0

8-1

0

9-1

0

3--

a D

H 1 STOR l

C

FUEL 0 I L CONSUMPTI ON, GAL,

0

t

:,

- LEGEND

-

- x=1.5 TON 0 = 2-0 TON - rn

= 2 5

TON

-

~ = 3 , 0 TON

-

_-

- _-

--

-

_-

--

-

- _-

--

-

- -

-

! I 1 ~ l l l ~ l f l : l ~ l l l t l ~ I I I I I I I I I I I 2w rcoa 8w l ~ l ~

i ~ m

aw MW 1800 2 _n u - 0

=

0 I- - - = _a -

- -

3 r

I-

-

i

! 2 -

8 0 rg

33

_w 8 8 0

(9)

F I G U R E 5

8:

0

5-1

9-1

0 0-- 0

0-1

8-

-I 0 ,*- den #* ***- a ' /ad W I N D S O R : A D D - O N HEAT PUMP a ) W l T H NO O P E R A T I O N A N D

b )

W l T H O P E R A T I O N , B E L O W B A L A N C E P O I N T

,

I

CU

-

- -

_-

**--A

-

-4--

-

0 -

-

*d#'

-

,'

,-

-

b

-

:-

-

_-

a

51 :

m

@--

a 0'- m 0 0 - - m

8-1

8--

_N 0 a .

-2

E

X

0 m

8

HI STOR I

C

FUEL

O

I L CONSUMPTI ON,

GZ.

-

LEGEND -

-

x = I 5 TON 0 ~ 2 . 0 TUN = 2.5

TON

-

A

=3.0

TON - -

-

_- -

-

--

d d

-

_{1 TON} ₌

_3.5

_kW - _-

-

1 G A L , = 4 . 5 4

L

1-

-

_-

I l l I l l t l 1 l [ l l l l , I f l l l l f l l l , I I I 1 _I _I I

zm

400 600 800

--

120b nm 18M)

-

b -

_-

- I 1 I L . I I 1 1 1 1 1 1 1 1 I , , I 1 1 t l t l l l l ]

-

I I I I I I I 0

- E

1 N h u - 0 I 0 t - - a

-

- p 3 r

I_

-

i

O Y 8 -, 8 0 -a

E

v

g

0

,-X

-

3 W Z - J 0 _n

1-3

w I vl Q n 0

-

z

(10)

X-

v

- 8

9

-

_LEGEND

-

Z- _rn

-

x =

1.5

TON

-

0 = 2.0 TON

:-

P

-

a=- TON

-

A =3.0 TON

-

8-

- 0 (D

-

1-

-

8- _m-

--

- _-w -

-

0

9 1

1-

5 -

-

1::

1-

8 -

-

- 0 I I I T I I I ~I I I I I I I I II I I I I I ~ I II I I ~ I I B I I0 I I

0 200 400 6M) 800 iWO ISlMl t4w 1BOQ

1 TON = 3.5 k W

1 GAL. = 4 . 5 4 L

H

l

STOR

l C FUEL 0 1 L CONSUMPTI

ON,

GAL.

F I G U R E 6

TORONTO: A D D - O N HEAT PUMP a ) W I T H NO O P E R A T I O N A N D

(11)

F I G U R E 7 O T T A W A : A D D - O N H E A T PUMP a ) W l T H NO O P E R A T I O N A N D b ) W l T H O P E R A T I O N , B E L O W B A L A N C E P O I N T 0

8:

0

8-1

8--

m

-

0 - - W 0 z m

-

2 C3

-

0-1

0 m

-

C ) < 0-- C3 N - z- 0

L C ,

C3

-

_-

-

_-

-

_-

-

_-

-

- -

-

I l l l l f ~ I ~ ~ ~ , I I I I I , 1 I I l l $ l l l l l f I I - I 1 I I I Q a r

5 1

I-

-

5 z

x--

o

P

-

c IL 5

=

g--

v, Q Z 0 U A 0

-

0-- 0

' -

0-1

0 0 - N 0 0

-

--

0 0 - 0 N

1-

2

8 --

m 0 0 0 -0 0

- - 5

G

W Z

-

2

--E

-

w x V) u a 0

-

a00 nma 1200 I400 ISMI

HISTORIC FUEL O I L CONSUMPTIW, GAL.

Z

-

- LEGEND ___--a -

* I d d

x 1-5 TON #a_ a* ELECTRlClPl CONSUMPTION

-

0 = 2 0 T O N

,,,,

-

- - 3 - - - 3 - - + - - 3 - - - - g

-

TON * **= J/--*- ---a . WITHADD-ON

A =

3.0 TON

- -.

-

_-

-

* - - - -

-

b

1

-

FUEL OIL

CONSUMPTI0

-

=--+---e-

-

_WlTH_ADD-ON 1 TON =

3.5

kW

-

- 1 GAL. = 4 . 5 4

L

--

-

- t 1 1 1 t 1 1 l l l l l t l l l1 l I I I I I I I I I l I I I I

-

I MW) 400 600 I I I I t O 0

,

X

I (Y 0 P u g

-

- - 3 s 1 - 8

z

=

Q

--

0 S - , 8 3

E

N 0

(12)

F I G U R E 8 0

I<

8--

P

8--

Q 0 W 0 - - z

" -

-

2 n

-

A

X--

0

* -

1/1

-

J 0 Q 0 - - C3 1 T O N = 3 . 5 kW 1 GAL. = 4 . 5 4 L

a

-

__----

---A

-

__--

0

--

-

7

, 0 P 2 m

-

A

-

_____---_-_

-

d

--

X

.o

-

&----------I- 9

---

-

---

-

-4

v

G

W Z

-

A ,,8 0 E

MONTREAL: A D D - O N H E A T PUMP a ) W I T H

NO

O P E R A T I O N AND

b) W I T H O P E R A T I O N . BELOW B A L A N C E P O I N T

-

_-

Z

-

0 - l r l l ~ l I l l l

.

i 4 I . :

.

, , , l . , ~ ~ ~ ~ ~ ~ ~ ] [ ~ ~ j ' 0 0 I r 1 I I I I I wl < a

-

0 n Z u 0 0 0 I

,

E

2 C3 I- n

-

u 3

-

LEGEND

-

2

8 -

X

=

1.5 TON - 0

=

o = 2 0 TON 4-

x

E

a

P -

_-

n = 2 5 TON

-

3 C a

-

a =

3-0

TON

-

c

s

-

= X--

4

2

Y V1 m

-

_m Z

-

0 - 0

-

_-

8;-

--

a

0 --, 0 rg

-

0 - 0 - - 0 f

-

1- 9

-

0

-

a-

-

N

-

--

z

CY

-

0 I : l f I f l l I i l t l I f I ~ I ; l I I I I t

-

0 0 290 4w 600 M O 1WQ mm 1400 isMl

(13)

F I G U R E 9

8:

8-

P

X--

m Om- W z

= -

-

1 n

-

9--

0 VI

-

--I 0

8'-

0

-

Z 0 ' 0 0

FREDERICTON:

A D D - O M HEAT PUMP, a1 W l T H NO O P E R A T I O N A N D

b ) W l T H O P E R A T I O N , B E L O W B A L A N C E

POINT

-

3 - - _-

-

--

-

_-

--

-

- d -

_-

-

_-

-

- 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 4 ~ ~ l l ~ ] ~ ~ ~ ~ , ~ , - I t I 1 1 1 t

-

8 c

8 ₀

s

8

u w

E

*

--g

z

W z

-

2 --E5 n - , o ₁ V) a 0

-

0 Z

s-

s @ - I-

-

5

g

o

e

-

+ a E

2 3--

Z 0 U 0

-

u-- 0 ' O -

8-1

8--

N b CI

HISTORIC

FUEL OIL CONSUMPTION, GAL.

-

LEGEND

-

x=1.5 TON 0=2.0 TON - n = 7 TT6N

-

_{= X O}

TON

-

_-

-

1-

-

_-

-

_-

1 TON = 3.5 ItW

--

- 1 G A L . = 4 - 5 4 L 1

-

_-

l l . l l l 1 l l l l l f l ~ 1 l [ 1 ~ t ~ I ~ I 1 I I I 1 1 1 I I I I I 1 1

2 M 4w 8MI 800 IWW 1200 WOQ 1BM)

0

- g

e

c

n n e

1-g

r

- 2 3 f 0 3

1-6

At 0

f

a

--3

2

N C3