Carolina Gardening: Greenhouse heat advice, please, 1 by donnacreation

donnacreation wrote:
I recently bought 4 GH's from Lowes, and each measures 6'x8'x7'tall. I combined 3 and placed a Delonghi oil filled radiator space heater in the center, but it's only raising the overnight temp by about 6 degrees. On my back porch, which measures 16'x18', and the ceiling slopes from 12' to 8', one of these heaters raises the temp 15-20 degrees. I won't have a 240v connection for the GH's until next year, and I'm wondering if there's a 120v heater that would do a better job than the Delonghi. Please advise.