I am planning a greenhouse and was trying to come up with an economical way of heating and cooling it. I was thinking of laying a vapor barrier then foam insulation then a pex heating loop covered by 6 to 8 inches of sand covered by a few inches of pee gravel. Heat source would be solar with gas back up. Do you think this would work or would it be so inefficient as to be a waste of time. Also thinking about a simple cooling system that would be a fan with cooling pads that I will pump pond water over with a gravity return to the pond. Not sure how much I will increase my evaporation losses to the pond, Iâm concerned it may be considerable. May have to go to an inclosed exchanger. Does anyone know of a formula to figure how much surface area per volume of air, water temp or do I just guess?
Yes that will work. A gas water heater is a good source for the gas portion. Perimeter insulation (foam type vertically in a trench) is also suggested.
Come on people we need some advise here. Zack, you didn't say what your intended use for the green house would be, but that sure sounds like a lot of expense and trouble for a green house in Texas. If you are going to use it like me (starting seeds early, and maybe a little season extending in the fall/winter), just build it under a non-evergreen shade tree with a southern exposure, put a door in the top part of one of the end walls that you can mount a box fan in, plug the box fan into a temp. controlled plug-in, this will help keep it from getting too hot, close the door at night this will help retain the heat stored during the day. I don't have a temp. controlled plug-in and just plug the fan in if the plants look too hot, but wish I had one. I don't know a lot about them so I hope someone that does will help us out. Good luck, Herb.
Herb, The greenhouse will be used for an aquaponics system. Heating and cooling are primarily for the fish. Cold will be the most harmful to the fish and plants. The goal is year round production. With the mild climate of S Mississippi I may not need the hydronic system. I have not done a cost break down yet of the heating system. It may be cheaper to use standard LPG greenhouse heating. I like to look at all of my options
Zack, Aquaculture is something I do not have any experience with, only some research as I had/still do find it interesting and intriquing. I remember an article about attaching the setup to the back of a chicken coop and also including plants in with the fish, I like that idea. I would very much like to give this concept a try once we get settled into a permanent location. Check out the water temp. required for the fish you choose. Your area may be fine year round with only some oxygen and filtration required. Hope you/we get some input from people that either have or are still doing this. Herb.
