What type of temp differences do you notice in your greenhouse when using the intensive method of composting? Where is the best location to heat the greenhouse? Should the compost be in the center and radiate heat out? Or should it be along the coldest/northern wall of the greenhouse to complement any southern passive solar gain?
Sorry Gail, I hadn't seen your post till just now. I've tried the hot compost but it's slower (wood chip based) and in a metal bunker and it doesn't work that well. If I were to try an open hot 21 day pile I'd put it somewhat central and ideally a bit more to the north or out of the way.
One thing to worry about is the ammonia and other stink that is coming off the pile gassing you out of the greenhouse.