[gkainz]

And I used 1 30# bottle in 5 days with lows of 0 and highs of 20 with wind and snow at 8000' elevation last hunting season. However, I winterized, and run the furnace at 55* at night and off during the day, and ran an electric heater when I had the genny running to augment, so as they say "your mileage may vary". All you can do is test it out.