Greenhouse Growing

I live in coastal SC approximately 25-30 miles inland and wish to complete my GH by adding a heating system. I have a 10x14 double polycarbonate. Has anyone had experience with a 120v heating system? I am hoping to avoid running a 120 and 240v lines. Any info is appreciated. Idea

I have 3 hobby greenhouses currently operating here in cold snowy Idaho and now heat my greenhouses primarily with natural gas but when electricity was less expensive, I always used electric heaters in the typical household outlets (120v). Since electrical greenhouse heaters don't require venting to the outside, low oxygen levels aren't usually a concern which isn't true with my natural gas heaters now.

:)

I use a 45000 btu forced air RV furnace it runs on 12-24-120 volts have an automotive 12 volt battery in case of power failure. They run about a month and a half on a 40 lb bottle of propane. We average 30-35 in Jan-Feb.lowest this winter was -22 I needed to vent the exahust outdoors since I grow Orchids My house is 10x24 12'tall You can get them on line at e-bay for 200. up