Anybody Have A Geothermal Heat Pump?

[DanS]

Anybody here have a geothermal heat pump supplying heat or air conditioning to their house? If so, has it worked as advertised? How much did yours cost? Any maintenance problems? I'm interested in this from a conceptual standpoint.

For those who have no idea what I'm talking about, in short it uses coils in the ground as a heat sink in the summer and heat source in the winter. Supposed to lower your monthly heating/cooling costs at the expense of some capital costs for excavation and installation. Here's some info...

http://www.eere.energy.gov/erec/factsheets/geo_heatpumps.html

[Dinner]

They'd work but I'm willing to bet they cost much more to build then they are worth. I.E. the payback on intial costs will likely never occur much less a profit.

[DanS]

I have heard that the coils cost between $10,000 and $15,000 for excavation and installation. On the lower end of that range, if you sink the coil in your pond. Some houses would have a reasonably quick pay-back period, using these assumptions.

If they use plastic pipe, it should be pretty inexpensive.

[chequita guevara]

I've always heard they were expensive initial investments, but they do pay themselves off, eventually. I learned about in 8th grade, which would be 1980-81.

It was $5 grand back then, or so I seem to remember.

[DanS]

Supposedly, plastic pipe has become a lot more durable since then (and cheaper, IIRC). The stuff we used in the oil field is better, for instance. PVC pipe seems to be used more and more nowadays for plumbing.

[chequita guevara]

But plastic pipe probably doesn't transfer heat very efficiently.

[Dinner]

It it breaks when water freezes. In cold weather locations soil can freeze several feet below the surface of the ground.

[aaglo]

With proper pre-design it is all the money's worth. Easily.

Many of my friends (all of them are construction engineers who have built their own house) has the pump, and they are satisfied with it.

[Peter Triggs]

aaglo,

How cold are we talking about here? I was thinking of putting one of these things in on some property I own in Canada, but, like DanS, wondered if they work as advertised.

[Buck Birdseed]

My parents have one and it's worked fairly well, but it has broken down a couple of times during cold spells. The repairman rechkoned that wasn't the pump's fault though.

[Az]

How about government regulation to make all new buildings have those? It seems like a pretty good idea.

[DanS]

Don't think that would be too popular in Peoria, Azazel. However, some electric cos. in the US give small subsidies for this type of thing, since it reduces peak demand.

[VetLegion]

I think that in Germany government supports heat efficient housing and that includes these.

There should be few problems with cold as the coils need to be pretty deep, where the soil doesn't freeze. At least a meter, depends on the climate. The costs of excavating a big area of soil can be high which is why nobody I know has it while many know about it.