In mine with the factory electric heater and a electric cube heater down to 5 above. I also have a matrices pad heater for when it gets colder. I do leave the roof vent open just a crack to help with condensation If need be I also have a propane furnace
. (That Ron installed) I'm going to attempt to add extra insulation in the roof in places that Jim Palmer didn't put any. One more thing I take the foam mats that lock together like Legos to help insulate the floor.
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