? about boondocking with furnace

The furnace fan sucks 7-10 amps from your batteries. However, it is, by far, the safest way to heat your rig, on par with the Platinum Cat, which has less of an amp draw... but it throws all the combustion exhaust outside.

I have not read much about the Olympian Wave heater... I wonder how it compares to a Buddy heater, especially for long boondocking runs.