Best way to heat a small greenhouse?

[curtisconners]

Here I am, starting threads like crazy again, but that's irrelevant.

My dad told me that he was planning to build me a small greenhouse this summer (not sure how big yet) and I was hoping to heat it to 50-60 degrees in winter so that my neps could stay somewhere more humid and sunny in winter than my house. What's the most efficient means of heating a greenhouse in winter? I'm in Ohio.

 

[bijillon]

Small a/c idk if they with heat but some are pretty good or a small space heater.


Happy Growing, from Dillon!