Using a geothermal system for house with 275' mine attached?

nutsbolts

Hi there, my house is attached (via the laundry room) to a 275' tunnel with a constant 55 degrees year round. I currently have a hot water boiler system installed (boiler is 8 yrs old, system/house is 58 yrs old), but my gas bills are very high during the winter ($150/mo ave plus electric). I'm intrigued by the idea of heating the 55 degree air that is available by opening the laundry room door (the house is literally attached to the mine portal, so no outside air) but don't know what the options are - geothermal, heat exchanger, or something else? Anyway, just exploring options. Thanks!

SWEI

Several options, but we need more information in order to point you in the best direction.

What temperature water is required to heat the house on the coldest day of the year?

What are your fully loaded prices for gas and electric? Divide the amount at the b0ottom of the bill for last month by the number of therms, kWH, or gallons used.

JUGHNE

Here is a crazy idea; assuming the tunnel is at least 6' in diameter could you put in an air to water heat pump. Go down the tunnel 30-50' (some friendly length of line set) with a standard outside heat pump. Some design with horizontal air flow as a lot of old units had. You would just be moving the same air around milking heat out of the earth.
Probably don't want to bring tunnel air into the house, too cold anyway, and maybe nasty.

Eastman

What kind of mine is it?

JUGHNE

Have you tested your house for Radon Gas?

Eastman

Please post a video tour of the mine.

hot_rod

Any water in the mine. There is a mine up in MI that they use the 55 degree water to supply a water to water hp

There was an article about it in a recent trade journal.

Eastman

@hot rod Any suggestions for a river?

hot_rod

We had a job in Wisconsin where they got permission to put a geo loop in the river near an old mill diversion. It was a winner in one of the Caleffi Excellence contests

I also met an engineer that used the city water mains in a town in Nevada as the loop. But they ended up freezing a 4" main and had to spread the connections apart around the block to get more surface area involved. A plate HX isolated potable water from the hydronic loop