We put a ventless gas wall-mounted heater (propane) in our living room after being without power for 11 days in "07 due to our horrible ice storm. Our living room is the coldest room in the house anyway, so this can be turned on when the room is a little cool. It would keep that room and the dining/kitchen warm during a power outage if turned on "high"
The gas company came out and installed it.
HTH - hope this helps.