[conradpdx]

Depending on your location but many people actually put their exchangers into ponds and lakes. In fact, I believe these are typically the most effecient heat pump systems. Since, I don't live so close to a body of water I never researched this type of heat pump but if you have rights to that lake and it never completely freezes you could probably save a ton of money with a heat pump.

I did look into burying my coils when I replaced my 60 year old oil furnace with an electric heat pump this last spring and the cost went from $12,000 (with complete electrical upgrade) to something like $25,000-$30,000 guess from the estimator (he said he wasn't sure cause it's so expensive he's never actually sold one). Most of that cost is in the massive amount of copper pipe needed.

But I'm happy to say that the new heat pump not only saved us in heating fuel costs, but the old heater used so much power for the fan and ignition and ditching the two window AC units that even our electric bill dropped by about $100.00 a month. Not bad, and it's all electric so it's the most adaptable of systems on the market when it comes to future energy. (Sorry gas and oil---you're all dinosaurs).




<edit> BTW...there's a lot of math involved with DIYing such a system. You need to know how many BTU's you need to keep your house X degree's and how much insulation your house has, how much heat loss etc etc.... Not to mention you gotta plan for drainage of water condensation in the coil systems in a buried line system. It's a ton of work and money and destroyed yard if you screw it up and it doesn't work right.

I'm usually all for DIY projects, (especially since I work in construction) and I'm afraid to say a buried exchanger heat pump I'd leave to the professionals. If for no other reason that if it doesn't work right they should offer a guarantee and they have insurance to dig it up and fix it should something go wrong with it or if it or they cause damage to your property.