I've only been running it for about 4-5 hours inside with the exhaust temporarily going out the wood stove flue just to test it out and I did run it @ several different settings out side for about 2 hours as well just to burn off any new smells and in all that time the fuel level only dropped about 3/4 "-1 " on a #5-6 setting with a few15-20 minute bursts @ the #10 setting ,,Very Efficient Indeed. It's 31 F ,damp and windy outside and it's maintained my 2000 sq ft house @ 69 F . My house is well insulated so that helps, but that's still Amazing IMHO !I mounted mine on a small 31 dollar (on sale) Harbor Fright welding cart so I'll be able to use it for different purposes and can Tee into any duct work I want to, ie; the house, off road camper, my workshop, the garage and I guess it could be used to heat my big tent as well for campground use ? That way the unit is not only portable, but pretty safe being outside.I just hope it has good longevity but in just the few short hours I've used it ,,I'M VERY VERY IMPRESSED !The control panel had come loose in shipping as it is only attached by 2 sided tape and there were a few small dents , dings and a small bend in the case and a few surface scratch's but being a body man I was able to straighten it all out OK and compound out the scratch's without it even being noticeable. None of this was very serious but It could use a bit better packaging for shipping than the original box IMO . It still has a bit of plastic/electronics/ smell and hot smell from the stainless exhaust pipe curing still, but not horrible & I think that will go away eventually? BTW,,,Defiantly get a couple better hose clamps for the exhaust pipe, the ones that come with this unit just WILL NOT squeeze down the exhaust pipe down tight enough so it won't leak exhaust gasses.It shipped very fast as well,,,one happy buyer so far. Other than the somewhat sparse packaging protecting the heater.
Jason 
