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Any Geothermal experts here?

Baconator

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Im in the process of putting up a 50x80 shop, I am planning in floor heat for it.
The current plan is to heat half of it, and the other side will be used for storage. I am planning on piping PEX through the unheated half in case I ever find a need to heat it.
Geothermal has always interested me, but never really had an opportunity to do anything with it.
I feel like this is the perfect opportunity to try it out, I have plenty of room to make some loops.
Everything I have read says the earth stays around a constant 50F about 6' down, I like my shop around 50F in the winter time to work in. If I need it warmer I may set up a furnace or something to just bump up the air temp for a few hours. My question is how to setup the geothermal loops, and how much length will I need?
Everything Ive read about it uses a heat pump, I havent found much info on just circulating to maintain a lower temp.

I would place my loops in front of the shop where the machines are parked, there is plenty of room up there, however there will be a bit of traffic over the top of it. 6' down shouldnt care about that though.
Is Black poly the standard for this type of thing, or should it be PEX?

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It will not work without heat pump. We have dug a few holes for a few systems. They were 8’ deep 300’ long 10 loops or so to do a 2500 house. My number may be a bit off this is just off memory. A heat pump will cause the frost to go down 6-8’ in the area of the coils.
 
Expert? No. We built our house in '09 so there's probable some new stuff out there. We have a forced air system that is like a heat pump without the outside coil. For a 2,400 square foot rancher I dug 3 trenches 8' deep and 250' long each. Trenches were 8' deep, 2 pipes in each. Pipes laid on the bottom rolled out to the end, put 4' off fill in and roll them back to the start. The loops all terminated at a manifold in the ground so just a supply/return into the house. About 3000' of 1" or 1 1/2" , can't recall. More expensive going in but I would do it again.
Screwzer rant off.
 
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Not an expert, but I have two facilities that we maintain that have geothermal condensing water to several hundred water source heat pumps and chillers.

Most lines are fused HDPE. There are hundreds of wells of varying depths none shallower than 125'.

Not sure how the horizontal loops work. I have recieved a call from a peer who had a facility on a hill designed by the same firm who designed ours because in the middle of a long heat wave they were getting 80* water back from the return. Turns out they had heat soaked the hillside:eek: Granted it is a 500k sq/ft medical with a massive heat load from all the equipment.
 
Everything Ive read about it uses a heat pump, I havent found much info on just circulating to maintain a lower temp.

where are you building
if you're just trying to keep it a couple degrees cooler in the summer (mainly just condensing the humidity out of the air) you'll probably do okay, heating in any sort of winter, you'll need something to make the temperature difference significantly greater (a heat pump)
 
[486 said:
;n139655]

where are you building
if you're just trying to keep it a couple degrees cooler in the summer (mainly just condensing the humidity out of the air) you'll probably do okay, heating in any sort of winter, you'll need something to make the temperature difference significantly greater (a heat pump)

I would shut it off in the summer, no need to cool it.
It would only be run in the winter, Im in CO just south of Denver. We have mild winters compared to the midwest. Frost line here is 36".
 
This thread reminds me of Screwy and his geothermal discussions.

Wish that dude was still around.
 
I would shut it off in the summer, no need to cool it.
It would only be run in the winter, Im in CO just south of Denver. We have mild winters compared to the midwest. Frost line here is 36".

problem is that your concrete pad is a giant radiator that has to be warmed up before it can push heat to you. that's why min supply temp is near 120 in my house. my boiler is set at 175° off 165° on. if water is only coming in at 50°, it will be too cold by the middle of the run to heat the pad up let alone how cold the return line would be. you wouldn't get enough heat in the pad to do any heat rise at all.
 
I worked a couple months in a shop that had geothermal/radiant floor heating system, don't remember much about it, except the heat exchanger was inside the shop and it kept the concrete floor a nice mellow temp. If it was really cold outside, the owner would kick it up a degree or two. That warm giant concrete heat sink made the place feel so much warmer.
 
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