Community Forums

Vette4ba · 11-09-2013, 01:51 PM

If I am just running the fridge and furnace on propane, how long will my 39 gallon LPG last? 1 week, 2 weeks, or more? We are doing very little cooking with the propane. I know this question is vague and is dependent on many factors, but a general answer will do.

Thanks.

KJD · 11-09-2013, 01:55 PM

Short answer 3 to 4 days

palehorse89 · 11-09-2013, 01:58 PM

I see you are from Buffalo, so if you are using there in the winter , 3-6 days maybe , down south a lot longer. With what you posted and are asking it is really hard to answer. 1 gallon of propane produces app. 92,000 BTU'S of heat , so if you add up the btu's of your furnace and estimate how much it will run in a hour (depends on outdoor temp.) you can figure it close. I hope this helps with your question.

BFlinn181 · 11-09-2013, 02:06 PM

Mileage may vary. I think 3-4 days is short. It should last quite a while unless you have the thermostat set on 80º. You might think about one of these:
Removable Accu-Level Propane Tank Gauge with Magnetic back : Amazon.com : Kitchen & Dining
This and a cup of hot water will tell you the level of LP in the tank.

Ray,IN · 11-09-2013, 02:23 PM

3-6 Days??? on a 39 gallon tank??? Come on, my 5er would run longer than that on a 30 pound(7 gallons) cylinder for those two appliances. Palehorse gave you the correct formula to calculate how long your 39 gallon tank should last.

palehorse89 · 11-09-2013, 02:28 PM

Maybe re-read my post again Ray,39 gallons of propane, Buffalo winter, 15-30 deg. = not long. The furnace would be running about non-stop in those temps.

jesilvas · 11-09-2013, 02:44 PM

I've had a not well insulated fifth wheel w/a 30K BTU furnace in 30*F or so. It didn't run anywhere near non stop.
So let's say this: 92k BTU per gallon. 39gal ASME tank. Even filled at 80%, that's 31.2gal. That's 2,870,400 BTU.
I'm gonna assume you have a 40K BTU furnace and a big refr that uses 3K BTU. That is roughly 66.75hrs of use. Roughly 2.78 days of running time.

Vette4ba · 11-09-2013, 03:03 PM

Thank you everyone. I am leaving for Florida on Monday and am wondering if I need to "top it off" before I go. I am plugged into 30 amp shore power, so that is running the fridge until I hit the road on Monday southbound. I am keeping the furnace down around 55 just so the pipes don't freeze, so the furnace isn't running constantly.

jesilvas · 11-09-2013, 03:11 PM

Never hurts to top it off.

87Rockwood · 11-09-2013, 03:26 PM

Our 28 gallon tank will last us (full timers) at least 10 days during the worst of winter here in New Hampshire and we are not plugged into any ac power

CampDaven · 11-09-2013, 03:54 PM

39 gallons of total capacity is about 30 gallons of actual LPG. It cuts off at 75-80%.

I actually go a very long time on my 20 gal.
Filled it last August, still at 3/4. Propane only used for stovetop, and occasional furnace. We use ceramic heaters, elect hot water.

NeilV · 11-10-2013, 03:40 AM

In Manchester NH my 28 gal tank would last about 10 days this time of year however at the North End of Lake Winnipesaukee I would drop that to about 6 days in an occupied 35 foot fiberglass coach with 6.8 foot ceilings and thermopane windows originally driven in Alaska. In an 40+ foot aluminum clad coach with higher ceilings and single pane windows you could use substantially more.

In Buffalo where you currently have sustained winds around 15 to 20 mph and can have night time temps well below freezing possibly down to the teens with 25+ mph winds factoring in the larger tank you might get a full week occupied and two or three weeks unoccupied.

Keep an eye on it and top off when you start your trip. Be mindfull that if the last time you filled the tank it was mid summer then you more than likely have a summer blend of propane which may not develope enough pressure to run the furnace if it gets below freezing and there is a windchill factor to deal with. Tonight you will have windchill temps in the mid to low 20's to deal with while Monday night going into Tuesday the windchill is forcast to drop to 15 degrees. So it is probably a good thing that you will be gone by then.

You can top off the propane at many truck stops along the way along with most major camp grounds.

J Birder · 11-10-2013, 05:51 AM

Quote:

Originally Posted by palehorse89

I see you are from Buffalo, so if you are using there in the winter , 3-6 days maybe , down south a lot longer. With what you posted and are asking it is really hard to answer. 1 gallon of propane produces app. 92,000 BTU'S of heat , so if you add up the btu's of your furnace and estimate how much it will run in a hour (depends on outdoor temp.) you can figure it close. I hope this helps with your question.

Don't forget that the furnace looses part (perhaps 10% ?)of the heat out of the vent.

Joel