I have a home-built trailer that has a 6'x10' interior, with two fold-out bed platforms on either side that are 5x7 on one side and 4x7 on the other, for a total interior square footage of 123 sq ft. The two bed platforms have canvas/fabric walls and roof, but the main 6x10 area is insulated (aside from the great big holes in the wall where the bed platforms fold out). I'm about to replace the bed platforms with a better iteration that has rigid roof and walls, and some light insulation and better rain protection, which should hold warmth in better.
I'd like to have some sort of heating solution that works well in this rig. I've got a Mr. Heater Buddy radiant propane heater, but even on low output that thing only lasts about 5-6 hours on a 1lb canister. I want something that can run for 8-10 hours without having to crawl out of bed and change canisters in the cold. I wish the Mr. Heater had an adjustable output rather than only 2 settings... I could throttle it to a point where one can might last all night.
I know about the hose that is available to hook a Mr. Buddy to a big propane tank, but that doesn't really appeal to me. A big 20lb tank is a large object in this tiny trailer, and I don't want the tank inside nor do I want to build an access port to run a hose between inside and outside. I can get a 5lb tank, but anything smaller than 20lb carries a hefty price premium when buying a tank.
Anyone have recommendations for a heater that puts out 3000-10,000 BTUs and can run for at least 8 hours (ideally 12) without refueling, and doesn't use disposable non-refillable containers? I'm not looking to maintain 70 degrees, just keep the inside between 40-50 degrees when it's about 20 degrees outside. I'd like to be able to carry enough fuel to run a heater for a week of nightly use.
Some things I've considered but not sold on:
1. UCO Candlelier. I have a single-candle UCO candle lantern that I've used in a tent to keep warm on cold weather camping trips. It puts out about 1500-ish BTUs and can warm a small tent 5-10 degrees from a harsh cold outside temp. The candle will last anywhere from 8 to 12 hours. But, the candles are kind of expensive for 1 night of warmth. Supposedly the 3-candle version will put out about 5000 BTUs... but my fuel costs for 3 candles each night starts to get spendy. I've seen conversions where people use little kerosene lamps inside it made from little 50ml whiskey bottles and I've tried that conversion on my single-candle setup, but I find it to be sooty and unreliable with thermal expansion. I don't trust it to be safe. The caps expand and vapor starts to burn from under the cap as well as from the wick hole.
2. Kerosene heater. Up to 10k BTUs, yay. ~1 gallon capacity is typical, with a runtime of 14 hours. Kero is $8-$12 a gallon though, at stores. Not sure where I can find kero in a pump. With pump kero a scarcity, it's not a direction I'd prefer to go.
