Shadegardener said:I know the old English glass houses were heated with piles of horse manure composting away. Before modern heating and plumbing of course.
I think that's the difference between a "cold frame" and a "hot frame".
The hot frame has a foot or two of fresh compost buried under (?) 6-12 inches of soil.
I always wondered: doesn't that go anaerobic and STINK??
Since it can only produce a small amount of heat, it will be key to prevent drafts and other heat leaks if you want to raise the inside temp more than a few degrees.
