Slashdot Mirror
Tapping the Earth For Home Heating and Cooling
suraj.sun recommends a CNet post giving details of a still little-known energy technology: the ground source heat pump or geo-exchange system. This is distinct from so-called geothermal energy, which taps the heat in the earth to provide energy. Geo-exchange is suitable in scale for small industry — the article describes one commercial re-development of an old mill into apartment and commercial space that put in a geo-exchange at about half the cost of traditional fossil fuel-based alternatives. Even some individual homeowners are opting for this green method of heating and cooling, at a premium in price of about 50 percent (but costs are very much per-project, largely because drilling is involved). "Rather than use underground heat, geothermal heat pumps attached to buildings capitalize on the steady temperature of the ground or deep water wells. In effect, they treat the Earth like a giant energy savings bank, depositing or withdrawing heat depending on the time of year. "
Ah yes, kdawson.
This technology is HARDLY little-known, but places where people need lots of heating and cooling (the Northeast) are also places where electricity is uber expensive (thank you Greenpeace), so heat pumps aren't worth the $$.
I want to delete my account but Slashdot doesn't allow it.
Slashdot, which is supposed to be run by nerds, still doesn't support UTF-8. Simply use HTML entities next time.
What is a grundel, and why would you want to save it?
A grundel is an Old English bipedal monster or dragon, descended from Cain. I would imagine you would want to save it for yourself in order to keep your neighbor's dog off your lawn.
The heat pump that you are talking about has the condensor in the air. That is a horrible choice because yes, parts of the east (and midwest) can hit -40F (or C). If you are heating to say 70F, then you are looking at 110F difference (or ~50C). That IS inefficient and you are better off just doing straight heat from electricity.
But a geo-thermal HVAC is different. The condensor is piping that is 5-10' down in the ground. The temps are around 55-60F. IOW, you are pulling with maybe 18F/5C range. That is EXTREMELY efficient. In fact, if American were on these, our cooling in the summer would use something like 25% less electricity and our heat bill for the majority of the US would be a fraction of what it is. Even here in Colorado, a front range home who spends 150 for gas heating (a cold month) would expect to only pay about 50-60 for the heating.
One of the nice things about this, is most of the east coast's fuel oil actually comes from Venezula. If the east coaster would switch to this, we would see our imports from Venezuela drop to about 1/4 to 1/3 of the current amount (Venezuela oil is apparently low grade with lots of sulfur in it; pretty much used for diesel and home heating oil). BTW, EU makes heavy use of Russian natural gas for heating (which is why these games come into being during these times). The best thing that the west can do is move homes to geo-thermal and for American insulate better.
I prefer the "u" in honour as it seems to be missing these days.
Like most things, it's not for everyone.
Our quote for installation here was about $25,000 for a system that would heat/cool a 3000sqft house.
The house cost us less than $100,000, and we probably won't be here more than 3 years or so. No way in hell the house's value will be increased by at least the difference between our savings and the remaining cost of installation when we sell. Conclusion: we would lose money putting in that system.
It's sad, but unless these kinds of improvements become more highly-valued by home buyers or people stop being so damn mobile, for many of us it's just not worth it to make long-term energy efficiency investments in our houses.
I don't live in that area anymore and didn't take pictures, but I think you can get it with this mental diagram. It's easy, Just a cheap plug in water pump and they use the existing coil and the squirrel cage blower. You'll need to use adapters to match the sizes on the coil. I guess you could use like a cheap/small used swimming pool pump, I didn't see what they were using, they just said a "water pump", sitting on a little shelf alongside the AC unit in a box. It was remarkably simple. I didn't even pick up on it until I visited their store a few times (normal cool inside like it had regular AC running, small little store) and noticed the water pipelines dropping down from the back of the unit (you could see it from the parking lot), so I went over and checked it out, then asked them about it. The guy who owned the store just took the old AC when it died and modded it. The creek is around 40 or so feet away, runs year round, little trout stream in north georgia mountains, so it is more or less pretty cold even in the summer months. They just drain it in the winter.
Thinking about it, you could build one with a car radiator and a box fan (measure window to get sizes where you need to put it), same deal, just add the pump, then maybe a little sheet metal shroud to tidy it up so it looked good. I've been meaning to build one myself, we don't use AC here, but I water the garden so much with cold well water that I keep thinking..hmmm..might as well. Just anther project, and I was going to put an underground tap out there anyway to eliminate hundreds of feet of garden hose out on the ground.
As I see it, the big problem is that cap and trade is spectacularly susceptable to rent seeking and regulatory capture. A carbon tax levied on non-renewable energy to offset negative externalities is much easier to both administer and understand while providing incentives through economics.