In the nordics it is common to have ground source heat pumps (brine in closed circuit pipe or bore hole) that are run backwards in summer to cool the house while actually assisting in storing heat back in the ground to extract in the winter. It’s a bit like regenerative breaking on electric cars.

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jjtheblunt 4 hours ago | parent [-]

There was a new in 1988 house in Champaign, Illinois, USA that used the same system, and i mention that because it was a normal modern house, and it's the only one i've heard of with that system.

It seems so smart.

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zdragnar 28 minutes ago | parent | next [-]

There's a pretty significant upfront cost in getting them drilled, and many homes need the vertical drilling if they don't have sufficient yard space for a horizontal system. It gets harder if you have your own septic drain field too, as that will complete for yard space.

The cost difference is pretty massive- 3-10x for a vertical system. If you live in a city or a suburb with tiny lots, that's your only option though.

Nat gas and central AC are way cheaper.

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maxerickson 2 hours ago | parent | prev [-]

It's expensive. A relative has one in the northern Great Lakes, they wouldn't have installed it if their house had access to natural gas.

	▲	zrail an hour ago \| parent [-]
		Our house came with one and we upgraded the unit a few years ago. It's very efficient in terms of units of energy consumed, but in my area of the world gas is significantly cheaper than electricity so it ends up being expensive to run. That said, we will install solar at some point and then it'll be "free" HVAC.