I know a wilderness lodge 30 air miles from Juneau that uses a propane gas-fired coil heater. I don't know how economical it is but it works very well indeed.Here in town a friend installed an electric-fired heater and he and his wife love it. (He installed it himself.) He says it paid for itself very quickly and saves them thousands of dollars a year. Their house isn't small- it has three levels- a small apartment on the ground level and a two-story house above it and it easily handles their needs.
Ebbie