AC heater VS Propane Furnace

[Superpro14]

When parked and hooked to Landline for power and paying for power usage, is it cheaper to heat the MH for a month by the AC heater or by the Propane Furnace. Have always used the Furnace in the past.
Thanks Bluenose

[jacwjames]

How cold is it, how often does the furnace cycle? How much do you pay for propane, do you have to drive and go get it. How much are you paying for power $/KW. Do you have a AC with heat pump or would your run small cube heaters.



If it is really cold your basement probably is heated by the furnace, so you would have to run a heater in the basement to prevent pipes from freezing.



A 30,000 BTU furnace will use about 1/3 gallon of LP an hour if it runs continuously. In mild weather it will cycle.



A small cube heater may use 1.5KW and hour. So in 24 hours it would use ~36 KW. At home my electric cost $0.13/Kw. So it would cost ~$4 to run a heater a day, ~$120/month. Less if it cycles on/off.



Lots of variables.

[Old-Biscuit]

What do you mean by 'AC Heat'?
Portable space heaters or A/C Heat Pump?

How cold is it?

[DerekF]

Originally Posted by Superpro14

When parked and hooked to Landline for power and paying for power usage, is it cheaper to heat the MH for a month by the AC heater or by the Propane Furnace. Have always used the Furnace in the past.
Thanks Bluenose

Here’s a recent article about it. Might help.
https://letsrv.com/rv-propane-heater...ectric-heater/

Happy holidays

[Superpro14]

Sorry should have supplied more info, Tampa area Fl, sometimes very seldome we may have to scrape the window on the car so not worrying about the Basement and I was referring to the strip heaters in the AC units 1999 Monaco Windsor I usually burn a tank of Propane Jan, Through end of March and refill for the trip home to Nova Scotia usually cold enough that I drain the water on way home.
Thanks

[jacwjames]

Do you know what the power cost is $/KW.

Do you know what you pay for propane?


Considering where you are staying, fairly mild temperatures, I think it might be more of a matter of preference.

When plugged in I will use a small cube heater, the furnace cycles quite often and is annoying. But I've never done the math as to how much propane vs AC power.

[Jim n Wilma]

Some time ago I put together an Excel spreadsheet with embedded formulas to compare the cost of fuel for different heaters to produce a million BTUs. At a glance it's pretty easy to see the cost differences. Still remaining in your decision process is what source of heat do you prefer and is the cost difference worth it.

Attached is a screen shot using variables that apply to our area and systems.

Also attached, hopefully, is a link to the Excel spreadsheet you can pull up and change the variables like fuel cost and system efficiency to better reflect your system.

https://u.pcloud.link/publink/show?c...1KkTcnlj59rj07

[CP Traveler]

Thank you for the spreadsheet, nicely done!

[Jim n Wilma]

After I sent the reply, I wondered how our new to us Aqua Hot would compare. So I added diesel to the fuel sources, though it’s arguably a bit more difficult to figure Aqua Hot efficiency. The spreadsheet link has been updated.

Since the AH is also the water heater, it may operate continuously with greater heat losses, but should that “penalize” comfort heating efficiency. I’m thinking not. I’m guessing AH efficiency is on the order of an RV propane furnace, though I’d sure like hear any discussion arguing a different efficiency.

[jacwjames]

I like spread sheets as long as the data is accurate.


Question, how did you come up with 240% efficiency for the heat pump? I'd never seen that number before. I know it would also depend on outside temperatures. If it is correct looks like the heat pump is the winner!!

[Jim n Wilma]

Originally Posted by jacwjames

I like spread sheets as long as the data is accurate.


Question, how did you come up with 240% efficiency for the heat pump? I'd never seen that number before. I know it would also depend on outside temperatures. If it is correct looks like the heat pump is the winner!!

Jim, for the heat pump, it’s really called Coefficient of Performance (COP) which is commonly about 2.4. Remember, heat pumps just move heat and don’t produce heat like the other appliances. Heat pump COP varies with outside ambient conditions and not all units operated over the same range. Our old Brisk operates at 32F outside, though I suspect the COP starts approaching unity, especially when it enters a deicing temp range.

I tried to explain some of this in the spreadsheet link in my first post. Of course there are lots of other factors that may drive your heating decision.

[Camp CA]

We always use the heat pump to heat our fifth wheel trailer unless the outside temperature is too low to effectively use it.

[96 Wideglide]

Originally Posted by Jim n Wilma

Jim, for the heat pump, it’s really called Coefficient of Performance (COP) which is commonly about 2.4. Remember, heat pumps just move heat and don’t produce heat like the other appliances. Heat pump COP varies with outside ambient conditions and not all units operated over the same range. Our old Brisk operates at 32F outside, though I suspect the COP starts approaching unity, especially when it enters a deicing temp range.

I tried to explain some of this in the spreadsheet link in my first post. Of course there are lots of other factors that may drive your heating decision.

I don't think your going to see anywhere near 240% efficiency from any of the RV rooftop heatpumps!

A newish residential unit.... maybe.

[jacwjames]

I looked at the manuals for the Penguin II high capacity units I installed last year and also did a search on line. Could not find COP listed anywhere




But when we built the new house I had Daikin 19 seer unit installed and at 40F it shows a COP of 3.5 on the high stage and 4.3 on low stage. It actually shows they will work down below zero.