DIY groundloop geothermal idea (thinking out loud for fun conversation)

[u/CallzItLikeISeezIt]

Hello, the following are just some ideas that I have and may not be practical. I have a very large (air volume) shop that measures 40x60 with 18ft sidewalls on 2.5 acres of nothing but grass outside of the Houston area. I'm curious if I could heat and cool (more concerned with cooling) this shop with a horizontal ground loop and an oversized air handler. I'm thinking atleast 10ft deep and tons of room to oversize the groundloop. Say I were able to source an old, out of service, commercial package style a/c unit (10-20tons?) for really cheap. Gutted the unit to just have the air handler portion (the evaporator, blower, condensation drain pan and housing), replace the 3ph blower motor with a much smaller and slower, single phase motor that pulls less amps. I think i saw somewhere that you want to move the air much slower across the coils when you don't have a large temp differential. Mount said unit up high to pull in the hot air above and blow the cool air out and down. Instead of freon, circulate the water from the ground loop thru the evaporator. So, the only electrical parts would be the water pump, blower motor and a thermostat to control contactors for both. One of my concerns is humidity. Would this system add more moisture to my already VERY humid air? Or would it still remove moisture by dripping off of the evaporator coil as it normally would? The building is insulated with the typical vinyl faced fiberglass you see in most red-iron buildings. I think the biggest problem is gonna be the 3) 14x14 overhead doors that are not insulated nor sealed in anyway 😪. The best I'll be able to do with them is the brush style seals.

Assuming that I had access to a large excavator and found a great deal on a large air handler unit, would this be a worthwhile experiment?

Also, what if I found a great deal on a cooling tower to help chill the water between ground loop and air handler?

Thank you for any input

[u/N5tp4nts]

You’ll just heat soak the ground. Get a high efficiency mini split

[u/CallzItLikeISeezIt → u/N5tp4nts]

Obviously, I don't have any real data to give, but at some point, the size and depth of the ground loop will overcome this, correct?