Propane consumption

[martybmw]

I have a Alpine 3700FL and it appears to really suck up the propane. It has the Norcold 18 cubic feet refrigerator and I forget the manufacturer of the furnace and the on demand propane water heater. We don't tow it, basically it sits out our property where we do our off roading. Trying to figure out the consumption as have been amazed how quick the two 8 gallon tanks go dry. have looked but really haven't found any good guides to figuring out these consumption issues. Had my share of issues with both the refrigerator and furnace but know both working good. Initially I probably had the temperature set to low so the refrigerator was always running. Now it set at #2 most of the time and at bedtime turn it back to #1. We are totally off the grid have 6 AGM batteries 3,000 watt inverter and 1000 watt solar cells. So far power has been sufficient and have the Onan 5500 LP for back up (that really sucks up the propane.
thanks

[travelin texans]

The fridge & water heater use minimal LP compared to the furnace, it's a huge LP hog.
Or last 5er in extreme cold spells would go through a 30lb/7gallon bottle in 2-3 days, we were plugged into shore power & using portable electric heaters as well.
I went to the local LP distributor & rented a 100lb bottle w/ a contract to keep it filled & it would last about a month, more liquid equals more vapors.

[JRTJH]

^^^ What Danny said, the 7 gallon (30 pound) propane tanks won't last long in cold weather, especially in a larger RV. ...

Just to add to Danny's comment, there are 91,502 BTUs in a gallon of propane. Doing the math, a 7 gallon tank has 640,514 BTU's. Going "one step further, a 35,000 BTU furnace would consume those 640,514 BTU's in 18.3 hours of "furnace run time"... So, with the furnace running, say 7 hours a day, that same 7 gallon tank would only last about 2.6 days, assuming that NOTHING else was using propane.... When you add in the "on demand" (gas only) water heater, it's easy to see why with that kind of "cold weather operation" a couple of 30 pounders won't last much over 4 or 5 days....

Since your trailer is, for the most part, immobilized, have you considered a larger propane tank? You could get a local propane distributor to install a 100 gallon or even a 250 gallon tank, tie it into your trailer and take advantage of the "regular refills onsite" as well as, in most places, a significant discount on the per gallon price of "home heating propane delivery"....

[dutchmensport]

I have a Montana High Country (41 foot, 4 slides) and it sucks up the propane also. In 15 - 20 degree weather, I can expect a 30 pound tanks to go empty in about 36 hours. At zero degrees the furnace never shuts off.

One thing you have to remember about these Keystone Fifth Wheels (Alpine and Montana and MHC), is the fact, the furnace ducts are designed to blow under the floor of the trailer to keep pipes and tanks from freezing.

I am not exaggerating when I state that about 50% of your propane usage for the furnace blows under the floor and the other 50% blows in the coach living area. And that is a LOT of space to heat. And the colder it gets the more the furnace runs, until outside temps reach a point and the furnace never shuts off. That uses a LOT of propane.

On the plus side, your pipes and tanks will not freeze up until about zero degrees or lower (if you've taken no special precautions).

One thing you can do to help the propane usage is to take the time to seal up every hole, crack, seam, screw hole, joint, and anywhere that is not air tight UNDER the trailer.

You've got to know, the "return" for the furnace is under the floor of the trailer, and the "return" is pulling from inside the coach area AND from under the floor. All those little holes allows the furnace to suck in cold air, which is even harder to heat. Completely sealing the underbelly from the bottom side with Liquid Nails, Foam "Stuff" insulation, calking, sealers, more screws, and anything else necessary to plug every tiny pin-hole you find will make a 100% difference in the amount of propane you use. I did this the results were amazing. Plus, in the Summer months when the air conditioner is running, you don't get hot air being sucked in from the air conditioner, via the furnace return vent area (usually located in the steps going upstairs to the upper level).

If you pull the wall in your basement area and look behind that panel, you'll be shocked at all the light coming in. Every one of those sources of light is an open window for cold air to get sucked in .... THAT is one reason why your propane usage is so high.

One other thing too. Once you have all those holes sealed up, you won't have that draft on the bottom level floor any more. It will disappear.

The other reason for the usage is the shear size of the camper! It's just huge and a lot of space to heat. It's just that simple.