subterranean heating and cooling system
I have meaning meaning to reply about it but thanks hex for the images of how you built the subterranean heating and cooling system in the other thread. In one of the images was the term "subterranean heating and cooling system," so I did a search for that phrase and came up with some good links and info about how it works. I have a question for you though, have you tested it at different humidity levels? From what I have read, the warm air/humidity is cycled underground where it condenses there, and comes up as cool dryer air. So it seems to reason that the efficiency would be related to relative humidity. More humidity, more condensing, more cooling. I live in a dry climate, so I assume I would probably need to introduce a swamp cooler or humidifier in the greenhouse for better efficiency.