Trails And Tails wrote:
Then there's the fact that I'll be paying for 110 so why not use it instead of my LP. I do understand that we'll have to allow for the 12amp draw. We're planning a mountain trip next spring/summer and I'm not sure how cold it will get, but I do know it WILL be cold at times.
I think your biggest problem will be logistics.
A 1,500 watt heater makes ~5.100 BTU and draws ~12.5 amps.
Your furnace will be 30,000 BTU and about 75% efficient, so about 22,500 BTU.
So then in order to get close to the heat output of your furnace you would need more than 4 electric heaters. Now obviously the furnace doesn't run constantly but even if I you can get by with just 2 heaters running you will be pulling 25 amps out of a possible 30'ish maximum.
Also, in a lot of Class C rigs there is only one 15 amp breaker for all of the outlets. If yours is like this, you will have to get creative in order to run more than one heater.
In my experience one heater, even with a portable fan running to circulate the heat it really only takes the chill off a cool damp day.