Fuel Consumption of Propane Furnace

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Metalman RVer

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Dec 3, 2016
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On our used Glendale we have a Hydro Flame 8900-111 model 2540 furnace according to the literature that came with the unit. Not sure how many BTU's that would be but it does a good job.

It is getting quite a bit colder here in the north & last night when sleeping in the Glendale around 2pm we awoke to a temp of 52f inside..........out of fuel.  I had been keeping an eye on the two way valve & it has been showing green, but somehow I did not spot the that they were both low.  It was the first time that they went empty on us since owning it.

I am curious to know if anyone knows approx how much propane is consumed per hr in a furnace like that while running?  Would it consume a pound or more per hr when on?  Just curious.

 
It will totally depend on the furnace size and what you set the thermostat at and for how long. I have two,, a 20 K and a 35K,, when both are running it can get Hungary.>>>Dan
 
Furnaces use a lot of fuel.  How much propane it uses really depends on how long it runs each hour.  I would not expect it to use 8 pounds overnight unless it was 10 degrees outside and you were trying to keep it at 65* or higher.
 
Don C said:
LP-gas (liquefied petroleum gas) weighs 4.24 pounds per gallon and there are 91,502 BTUs per gallon, or 21,548 BTUs per pound.

And I believe RV furnaces are about 50% efficient at best.

We have a 42,000 BTU furnace so your rig must be a similar size. We found ourselves in 16F overnight temps and 25F daytime temps a couple years ago. We have a 32 gallon LP tank, so about 26 gallons usable. I think we were there 2 full days and 3 nights, and used about 2/3 of a tank if I recall. We're lightweights and kept the temp about 60-62 at night. Furnace ran about 3/4 of the time.
 
Sun2Retire said:
And I believe RV furnaces are about 50% efficient at best.

Doesn't matter ... the nameplate on gas appliances gives their BTU input, not heat output.  It's done this way so you can figure out it's consumption across variety of fuels.  A 30,000 BTU rated furnace will use about 1/3 gallon of propane per operating hour.

A 40,000 BTU burner will use a little more, a 25,000 BTU burner a little less.
 
We use a cheap electric heater from Walmart.  In the mornings we will turn on the furnace for about 10 minutes and then keep the chill off with the electric heater.

We dress warm.
 
Lou Schneider said:
Doesn't matter ... the nameplate on gas appliances gives their BTU input, not heat output.


Good point, I was mixing apples and oranges. Since the topic is fuel consumption per runtime only input matters.
 
FYI my personal opinion is it probably matters more how the rig is insulated, how many times you open the door, how it is ducted, etc. than the BTU ratings, because what you're looking at is energy in vs. energy out. A 40k btu unit will run less often than a 20k btu unit, but they will use the same amount of propane approximately to heat the same space, just trading off run time.

For my 26 ft travel trailer, with the thermostat set to 70 and outside temps around 40, it seems to go three or four days on one 30 lb tank.
 
We were in South Dakota this year in early spring, first time we ever used the furnace. Temps were in the 20?s at night and we kept the thermostat on 70. A 30 pound tank lasted about 4 days, but we did turn the thermostat down to 60 when we were gone fishing during the day. One surprise we got, we pay $2.31/pound in Kentucky (home is heated with wood primarily but propane backup). In Pierre SD it was .61 cents a pound. I wish I had my home propane tank out there on wheels. I would have totally filled it up. ?
 
None of the answers above matter unless you know the outside temp the size of the trailer how well its insulated etc etc etc its all subjective reason i say that is because at 0F my 38 ft 5er with dual pane windows artic package etcetc will blow through a 30 lb tank in 3 days - my 28ft el cheapo tt with little insulation single windows etc etc will blow through a 20 lb tank in 2 days
To many variables here sorry
 
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