Here is a statement from that independent review posted earlier.
"The heater only requires between 150-450 watts of power, the variable power tuned by an easy-to-use dial at the top of the unit, so we'd leave it on a few hours before we needed to be in the room, close a door, then return to find the room comfortably warm instead of unnaturally hot or ineffectively cold (about 10-15 degrees)."
Run it a few hours to get it warm, i think not. I can warm up my camper in about 10-15 min with my 1500w ceramic heater, or in less with my furnace.