# Thread: Estimating Cost to run heat pump vs. nat.

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## Estimating Cost to run heat pump vs. nat.

About how much would it cost to run a 10 seer hotel style heat pump instead of an 80% AFU natural gas F.A.U. with an electric blower?

California Electricity….. ~ \$0.30 x Kwh
California Gas………….... ~ \$1.63 x Therm or CCF

400 sq’ room w/ 2 un-insulated walls and 2 single pane windows.
Mild climate in Southern California near Disney Land. Almost never below 32*F
aprox 4 heating months

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Originally Posted by heater99
About how much would it cost to run a 10 seer hotel style heat pump instead of an 80% AFU natural gas F.A.U. with an electric blower?

California Electricity….. ~ \$0.30 x Kwh
California Gas………….... ~ \$1.63 x Therm or CCF

400 sq’ room w/ 2 un-insulated walls and 2 single pane windows.
Mild climate in Southern California near Disney Land. Almost never below 32*F
aprox 4 heating months

Not sure about the C.O.P. (Coefficient of Performance) range for a 10 SEER hotel style heat pump, but here's the math (plug in the right C.O.P. when you find it).

Compare the cost of 1 million btu's of heat.

Gas furnace with gas at \$1.63 per therm, 80% efficient furnace:
(1,000,000 / 103,000 btu per therm) x 1.63 / .8
= \$19.78

Heat pump with electricity at 30 cents per kw-hr (ouch!!), C.O.P. = 3? at 40F:
(1,000,000 / 3414 btu per kw-hr) x .3 / 3
= \$29.29

In the above example, gas is 68% cheaper than the heat pump (if C.O.P. = 3 at 40F) for the same 1,000,000 btu's of heat.

Good luck.

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Originally Posted by gary_g
In the above example, gas is 68&#37; cheaper than the heat pump (if C.O.P. = 3 at 40F) for the same 1,000,000 btu's of heat.
If Gas = \$19.78 and Heat pump = \$29.29 did you mean to say Gas is about 30% cheaper. Or am I missing something?

PS. Also I was wandering if you included the cost of the electric used by the F.A.U.

Thanks for the info.
Last edited by heater99; 11-06-2008 at 03:44 PM. Reason: more questions

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Originally Posted by heater99
If Gas = \$19.78 and Heat pump = \$29.29 did you mean to say Gas is about 30% cheaper. Or am I missing something?

PS. Also I was wandering if you included the cost of the electric used by the F.A.U.

Thanks for the info.
My bust.

Gas would be 32% cheaper.

(29.29 - 19.78) / 29.29 = 32%

Blower motor power costs not included, only the cost to produce the heat.

Take care.

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Would you assume that that 10,000,000 BTU,s would cover a winter season?

Annual cost for gas ………….....= \$197.80
Annual cost for Heat pump…..= \$292.90
Difference…………….................= \$105.00 per year.

Cost of installing through wall Heat pump ………...= ~\$Removed
Cost of installing Gas F.A.U. + duct + gas line ….= ~\$Removed
Difference………………..………………………...................= ~\$Removed

Extra cost of Gas FAU …= \$700
Energy savings …………..= \$105

The heater will be financed.
Diff of \$700 x 6&#37; = about \$40 a year
Add at least \$15 a year to run the blower.
Assuming no change in utility rates they would break even in about 14 years.

Q1. Dose 10,000,000 BTU,s sound reasonable for a season?
Q2. Dose this look right?

No equipment pricing in posts please
Last edited by HeyBob; 11-06-2008 at 06:37 PM.

6. Gas furnace at 80&#37; efficiency=\$20.38 for gas to deliver 1,000,000 BTUs.
If you include the heat from the blower motor, and the cost of electric for it.
It comes out to \$29.53 for 1,000,000 BTUs of deliver heat from an 80% gas furnace.

A heat pump (at a COP of 3 ) with 3.5KW strip heat kit to temper the air during defrost, comes out to \$29.29 to deliver 1,000,000 BTUs of heat, at temps requiring a defrost.

The question is, will the HP PTAC your looking at have a COP of 3?

7. Originally Posted by heater99
Would you assume that that 10,000,000 BTU,s would cover a winter season?

Cost of installing through wall Heat pump ………...= ~\$xxxx.xx
Cost of installing Gas F.A.U. + duct + gas line ….= ~\$xxxx.xx
Difference………………..………………………...................= ~\$xxxx.xx

Extra cost of Gas FAU …= \$xxxx.xx
Energy savings …………..= \$xxxx.xx

Q1. Dose 10,000,000 BTU,s sound reasonable for a season?
Q2. Dose this look right?
Edit the equipment and install prices out of your post, prices, and those kind of pricing questions are not allowed in this forum.
Its in the rules, Thank you.

8. Originally Posted by gary_g
Not sure about the C.O.P. (Coefficient of Performance) range for a 10 SEER hotel style heat pump, but here's the math (plug in the right C.O.P. when you find it).

Compare the cost of 1 million btu's of heat.

Gas furnace with gas at \$1.63 per therm, 80% efficient furnace:
(1,000,000 / 103,000 btu per therm) x 1.63 / .8
= \$19.78

A Therm is 100,000BTUs.

Good luck.
Or it wouldn't be a Therm.

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Hotel Rooms have sporadic occupancy. If the room is actually often vacant with an aggressive set-back, the payback for gas would be sloooow. Different story if it's rented all teh time.

ALso, this has everything to do with climate - does it get cold enough to need back up resistance? That changes everything...

10. Originally Posted by heater99
Would you assume that that 10,000,000 BTU,s would cover a winter season?

Annual cost for gas ………….....= \$197.80
Annual cost for Heat pump…..= \$292.90
Difference…………….................= \$105.00 per year.

Cost of installing through wall Heat pump ………...= ~\$Removed
Cost of installing Gas F.A.U. + duct + gas line ….= ~\$Removed
Difference………………..………………………...................= ~\$Removed

Extra cost of Gas FAU …= \$700
Energy savings …………..= \$105

The heater will be financed.
Diff of \$700 x 6&#37; = about \$40 a year
Add at least \$15 a year to run the blower.
Assuming no change in utility rates they would break even in about 14 years.

Q1. Dose 10,000,000 BTU,s sound reasonable for a season?
Q2. Dose this look right?

No equipment pricing in posts please

Please read rules re' pricing of equipment, I have no issue with the discussion of energy savings etc. Equipment pricing varies in different areas of the country.

Thanks!

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Originally Posted by larobj63
The room will be climate controlled year round.

Originally Posted by larobj63
ALso, this has everything to do with climate - does it get cold enough to need back up resistance?
The unit would not have backup strips
The project is in Southern California near Disny Land.

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Considering a Friedrich Twin Temp heat pump YS13L33
http://www.friedrich.com/products/Mo...?model=YS13L33

It is 11 EER.
A COP rating is not available according to Friedrich’s tec. Support

I don’t think more efficient PTAC’s are commercially available with a heat pump.

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Originally Posted by heater99
Considering a Friedrich Twin Temp heat pump YS13L33 , 11 EER
http://www.friedrich.com/products/Mo...?model=YS13L33
Do you think this unit would have a COP of 3 or better?

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