Propane Question

OK to bring an extra cylinder in extreme conditions. Can be hard to fill if the regulator shows red into the evening. Verify the hours of the filling station or store for exchange.

I boondock in early spring in northern MI, with night time temps often in the low 20s, in a popup. The furnace runs a bit less than 50% of the time, which is still too much for the single Group 31 12v battery to last all night, so I supplement it with a Buddy heater. I can make three nights like that on two, 20 lb bottles with some to spare.

In a hard side trailer you should be fine.

badsix wrote:
I would think your heater is not going to run continually. it should heat up then shut down then when temps drop inside it will come back on. like on for 5 min. then off for 5min. depends on how well your insulated.
Jay D.

I think he was trying to figure out "worst case". Agree if it runs all the time, that means its never warm enough to satisfy the thermostat. Assuming that the thermostat is set to anything below about 90, and temperatures are anywhere in the 0+ range and the doors and windows are shut it shouldn't run all the time.

There are a lot of things you can do to help. Insulated plugs for the ceiling vents, insulated covers for the windows, etc... Also, if you have 30 or 50A service, ceramic or oil filled electric space heaters can help stretch the propane. We don't typically camp in weather that cold, but we do use ceramic heaters along with the faux fire place electric heater even in 25-35 degree weather. We're already paying for the electric and filling propane bottles is a hassle.

Another thing to think about is liquids in all forms. Obviously water freezing is a concern. If you don't have an insulated and heated basement, you can easily get frozen water lines even with the RV being heated. Any water lines that run near outside walls can suffer the same fate. Our TT has an insulated basement. We disconnect all external hoses and store during sub freezing temps and haven't had a problem with internal plumbing. Other liquids to think about are batteries. Charged batteries shouldn't freeze, but if you run them down they will. Other liquids would be anything stored in outside unheated storage compartments...

I would think your heater is not going to run continually. it should heat up then shut down then when temps drop inside it will come back on. like on for 5 min. then off for 5min. depends on how well your insulated.
Jay D.

Thanks all for the responses!

I plan to take our trailer up the mountain to our local ski area, they have power hookups but want to prepare for worse case scenario and have enough propane to make it through a cold night.


Thanks!
Brian

rhagfo wrote:

Every time I had my empty 20# tank filled, it took 5 gallons to fill, our 30# tanks will take 7 to 7.2 gallons to fill when empty.

It shouldn't take 5 gallons to fill a 20#. Propane should weigh 4.22 pounds per gallon which equates to 4.73 gallons for 20#, so I was low when I said 4.5 gallons. That's assuming it's filled to capacity which can vary by who is doing the filling. Assumption is OPD should kick in at 20# but I don't know how precise those are. 7.1-7.2 gallons should be spot on for a completely empty 30# tank.

Also, to be fair, I did round the usage saying approximately 1/4 gallon per hour. So, assuming 91500 BTU/HR capacity 20000/91500=.2185745 gallons per hour or 21.64 hours for 4.73 gallons. All these calculations are very precise, but reality isn't so precise. I seriously doubt the 20K BTU is 100% efficient and exactly 20K BTU. I also seriously doubt that if you take 10 random 20# propane tanks any of them will hold exactly 4.73 gallons of usable propane. So, I would say approximately 20 hours of continuous run time from a full 20# tank. Again noting if you use exchange tanks they will almost certainly never be full when exchanged.

91,000 BTU per gallon of propane X 4.2 GA = 382,200 BTU / 20,000 BTU per hour=
19.11 hours

happy2rv wrote:
A 20K BTU furnace should use approximately 1/4 gallon of propane per continuous use hour. A 20# propane tank is 4.5 gallons, if filled to capacity. So, that should be 18 hours if my math is correct.

However, it is worth noting that 20# tanks, i.e. common grill tanks are not always filled to 20#. This is especially true if you use exchange tanks. Exchange tanks are almost always filled to somewhere around 15#.

Every time I had my empty 20# tank filled, it took 5 gallons to fill, our 30# tanks will take 7 to 7.2 gallons to fill when empty.

A 20K BTU furnace should use approximately 1/4 gallon of propane per continuous use hour. A 20# propane tank is 4.5 gallons, if filled to capacity. So, that should be 18 hours if my math is correct.

However, it is worth noting that 20# tanks, i.e. common grill tanks are not always filled to 20#. This is especially true if you use exchange tanks. Exchange tanks are almost always filled to somewhere around 15#.

You can figure from this. My 9000 BTU heater will run 2 1/2 hours on 1 pound.
Let me know if you need help with the math and I can figure it for you.