Propane usage

[crh3002]

Does anyone have an estimate on how long a 100 gallon of propane will last at 25 degrees.

[Iceclimber]

That is a tough one to answer with many variables, like for example what is the propane running besides heat and what kind of heat. I lean on my own experience due to these variables.

[rarebear.nm]

Very difficult to estimate. Nor knowing size, insulation quality, how warm you want to keep it, wind speed, window covering, etc. All of these play into propane usage. Not to mention furnace efficiency.


That said, in our 27 ft MH we get about two weeks of run time on the 17 gallon tank. In our 32 ft 5th wheeler we get perhaps 5 days on one 30 lb cylinder. But that's comparing apples and oranges. They are very different RVs and use them differently.

[johnpsat]

Do you mean 100lbs? A 100 gallon tank is large and not portable. There are 91600 btu's in a gallon of propane. If you know the btu rating of your furnace just divide to get gallons per hour. I.E a 30000 btu furnace will burn about 1/3 gallon per hour. 30000/91600=.32. This is using 100% efficiency. Using a 30000 btu 90% furnace running off a 100 lb tank (about 25 gallons of propane) you should get about 72hrs of furnace runtime, less if you are using other gas appliances. At 25* outside I would think your furnace would run at least 1/2 hour out of every hour depending on thermostat setting.

[crh3002]

Sorry, that would be 100 lbs. not gallons. My motor home is a 34 ft. Tiffin with two slides. I have never used it in weather this cold, just trying to get idea of when I might have to unhook and drive to fill station. Thanks.

[twinboat]

It must be around a 25 gallon tank.

People call them 100 lbs tanks but nobody puts RVs on scales to fill the tanks, its dispensed by the gallon.

[Shadow5501]

Tiffin uses a 24 gallon gross capacity tank. Filled to the 80ish percent maximum it has about 20 usable gallons of propane.

There are really too many variables to predict how long that might last. Probably at least a week. You can forecast by noting how many percent the propane level drops per day (assuming you have the Spyder controller in your coach), recognizing that reading is not especially precise.

If you have access to 50 or even 30 amp electrical service you can reduce propane usage by running the electric fireplace, heated floors, or just a small space heater or two. Regardless, be sure the wet bay receives adequate heat either via furnace run time, an incandescent light, or some other source.

[Camp CA]

Originally Posted by crh3002

.............how long a 100 gallon of propane will last at 25 degrees.

Long time..........if you primarily use electric heaters and occassionally use the propane furnace.............that is what we do.

[Gary RVRoamer]

Originally Posted by crh3002

Does anyone have an estimate on how long a 100 gallon of propane will last at 25 degrees.

Indefinitely, as long as you don't turn on furnace or propane water heater or propane fridge. But once you start to use propane appliances, all bets are off and its up to you how much those appliances operate and use fuel. And how well your RV is insulated, and how often doors or windows get opened.


You said a 100 gallon tank, but I suspect you mean 100 lbs, which is one of the standard sizes. 100 lbs of propane is about 20 gallons. That's equivalent to about 5 of the home BBQ tanks or a little over 3 of the larger RV trailer tanks (30 lb each).

[NXR]

How many BTUs is your furnace(s)? Our propane tank is 104 lbs or almost 20 gallons.

We ran the water heater on propane for a week and the gauge never budged.

We cooked pretty much every day in Florida in the winter and after three months the gauge still showed 75% full.

But then there was the trip three years ago where it was in the mid-30's at night. Our Suburban SF-35Q 35,000 BTU furnace burned about 1/8th of the tank every night...

We didn't have to run it during the day because it warmed up.

In a few days we'll be needing to use the furnace again and it's supposed to get down to 18 a few nights and stay below freezing during the day. T'will be interesting....

We will need to run the propane furnace at those temps because it's supposed to dump heat into the water-containing basement compartments although I cannot figure out how it does that. I'll find out, I guess...

Ray

[NXR]

Originally Posted by Shadow5501

If you have access to 50 or even 30 amp electrical service you can reduce propane usage by running the electric fireplace, heated floors, or just a small space heater or two. Regardless, be sure the wet bay receives adequate heat either via furnace run time, an incandescent light, or some other source.

That's what I do. I have a small 250 watt electric heater in the wet bay and it's plugged into a Thermo Cube. The Thermo Cube turns the heater on when the temp in the wet bay drops to 35 degrees F and turns off when the temperature rises to about 45 degrees F. The heater is set to High because it cycles on and off.

The heater I use: https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

The Thermo Cube I use: https://www.amazon.com/Farm-Innovato...HD2/ref=sr_1_2

Both usually can be bought at a big box store. The Thermo Cubes are used in homes to turn on gutter heating elements so that may be the department where can you find one.

That heater has a "safety switch" on the bottom so I need to set the heater on a small board to keep the switch pushed.

I put the outside weather station sensor in the wet bay so I can keep an eye on whether the heater is working.

HTH,

Ray

[Superpro14]

My 2 cents , ha. My MH ( 99 Monaco Windsor) has a 40 gallon tank which works out to 189 LB of Propane, in Fordia Jan first to April 1st I use a tank couple nights it will ice up the car windshield but we have the furnace on most nights, fridge on electric hot water on electric and in March the AC on electric power bills were 60 a month and the propane cost 166 for 3 months, hope this helps, MH is 38 ft. So first 5 days heading to FL furance is on 24 -7 as it is usually below freezing , on trip -28 in NH , there is now way to heat a MH at these temps if you drive over 55, its the same as having a door open, if you drive 70-75
Bluenose

[Mark_K5LXP]

Last year I did an extended fall trip and watched usage. 30' Class A, running furnace, water heater, oven/stove. Low temps mid 20's, daytime high ~45. No effort to economize, uses just under 5 pounds a day. One freshly filled grill tank carries me 4 days. Swapping grill tanks was simpler than pulling up stakes and getting the main tank filled so have done that a few times now.

Mark B.
Albuquerque, NM

[crh3002]

Thanks for all the replies. The trip is over. I ran my fire place and two small electric heaters. Hooked up my extend stay tank and after two weeks we use half of the 20 lb tank. It was very comfortable in the motor home. Temps were below freezing every night. The propane heater only kicked on at nighttime. I was worried about my Conure and dog but all turned out well. Thanks to everyone.