First, a couple of videos (very large scale for a large production greenhouse) another large set up smaller scale smaller set up (northern tier) 'hot' compost - like chicken droppings more to follow
I'd been looking at those as well, thinking I might try the thermal exchange with the compost pile and airflow pipe running under it and back into the greenhouse. It was the only passive heat exchange I'd seen that worked even when the sun wasn't out and didn't take up a ton of space inside.
Depending on the size of the pile, they can take up quite some space, assuming you don't go vertical. Some of my neighbors would have a fit - these piles are not exactly Art, eh? You can use the compost heap to hold your planting frames for a hoop-house that would be more acceptable for most Urban settings. Again, this could hold a large compost pile with added benefit of standup gardening.
there is a guy in micn that has a whole commercial operation using heat exchange from manure and compost... i think its under the greenhouse thread somewhere
Yabbut it's outside the greenhouse where I have plenty of room, as opposed to inside like using water barrels for thermal mass. I was thinking to dig into the ground about 2 ft to take advantage of the ground insulating the sides of the pile. There's a video out there somewhere where the guy runs the numbers on heat for a 100% above ground pile vs one that extends a few feet below surface and it's a pretty big difference. Lemme see if I can find it... Ahh here it is..
