Author Topic: Lowering the greenhouse floor below ground level?  (Read 3965 times)

CeeJey

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Re: Lowering the greenhouse floor below ground level?
« Reply #25 on: March 07, 2023, 06:02:43 AM »
I've been wondering the same thing ever since I started going for walks in those sunken parks out here during the summer and fall time; they're substantially cooler at the bottom (to the point of having to wear a hoodie at night when the surface temp is 80+) although that's more like eight feet of depth. I've known a few people out here who have used open partially-shaded pits about 3-4' deep to extend mid-season vegetable growing a little more into the warm season and swear by them. Too much work for me for lettuce in May, although if grocery prices keep going up...

Even if it worked though, it seems like for a greenhouse it would be a major flood risk during monsoon season for a large investment.

Tropicaltoba

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Re: Lowering the greenhouse floor below ground level?
« Reply #26 on: March 07, 2023, 07:24:48 AM »
I realize I have no where near the heat and sun of Phoenix but the low pressure misters work great along with air exchange. I live in the northern prairies, last summer it went up to 38c, but with low pressure misters (only 5 heads) and 1.5 air exchanges per minute I kept the greenhouse temp under 32c. With the air exchange alone it would have been about 45c (university of florida has greenhouse temperature modelling papers on their website).

brian

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Re: Lowering the greenhouse floor below ground level?
« Reply #27 on: March 07, 2023, 10:09:50 AM »
Yeah the guidelines on the effectiveness of evaporative cooling (swamp coolers) is based on day+night residential usage, but a greenhouse is only cooled during the hotter part of the day when relative humidity should be less simply because it is hot.