My wife and I are in the early phase of building a new house. I'm curious if anyone has any experience with geothermal ("geoexchange") systems for heating and cooling homes. I have checked out the www.geoexchange.org site and I am reading the different papers they have available, but I would really love to get in touch with someone who has some real-world experience!
My parents have had geothermal in their home for years. The first system was literally a prototype, and reliability was a concern after nearly 20 years of operation. They updated the hardware and now it performs brilliantly, and should keep doing so for decades. The initial cost of these systems is a little high, but the energy savings are well worth it. Electricity does nothing more than circulate the fluid through the ground loop, circulate the air through the house, and operate the heat exchangers. Alcohol-based refrigerants are now the preferred working fluid, and pose a very low risk to the environment. On top of that, you don't have to worry about the CO hazard posed by burning gas or oil.
Their house is in New England, btw, so it does have to put up with some extroardinarily cold temps in the winter. That house is always warm! I can't say specifically how much my parents pay to heat and cool the house, but they tell me it's much lower than their prior house, which was smaller and had electric baseboard heating with window air conditioners. Everything works great in the summer, too.
Thanks brick. We are looking at this as our "until retirement home" which means we will be there for a minimum of 25 years. Therefore I am looking more long term than if we thought we might move again in 5-6 years.
We thoroughly researched geothermal systems about 20 years ago, and ultimately settled on simply putting solar hot water. The payback period wasn't less than 7 years (my guideline at the time). The solar hot water paid for itself in about 2 years, and lasted 7 years, no complaints (the tank suffered from electrolysis and ultimately leaked). Given the cost of fossil fuels today, I would revisit geothermal, especially in the mid atlantic region. The only caveat would be a realistic ROI analysis.
My uncle has a direct-exchange system- refrigerant in copper pipes directly to the ground, no intermediary water loop. It's about 6 yars old, working like a charm in CT. Along with hydronic radiant on the 2nd floor, he keeps the (3000sqft) house at 75 and hasn't kvetched about electric bills ever! (And he is CHEAP)
There is something too elegant about working WITH the temperature gradient in the summer (and sort of in teh winter too) to pass up! Hopefully next year I'll be adding on to the house, to include a geo system.
With a smaller compressor that is indoors and not even compressing much in the summer and no exposed parts, failure rates should be far lower than with air-source heat pumps. Some get wiggy about hundreds of feet of piping in the ground, but look at everything else that is underground and works fine for decades! IIRC the industry can point to very good track records for 20-25 year lifetimes.
sidebar: To get the $300 federal tax credit (you probably already saw this on the geo site) you need to have a desuperheater, normally used to heat your domestic hot water. Free hot H20, at least in the summer. Makes it a possible tossup with solar hot water- though the solar will still heat the water in winter too, where the heat pump normally won't (or will preheat at best, using extra energy instead of waste energy). So you can make up that $300 in a year or so with soalr H20.
Last I heard the complet greenlight to include geo for the $3K (yes- thousand) federal renewable energy credit was not completed yet. It is implied, and authorized, but not foramlly funded yet. Is this still correct?
I haven't read about the $3k in energy credit yet. I just started researching this last week and was focused more on long term reliability and savings than tax implications. I'll let you know if I see anything regarding the credit.
As you should be more focused on those. Tax bennys are just that. Nice to get and may tip the balance for some, but should never be the prime motivation.
My uncle has a direct-exchange system- refrigerant in copper pipes directly to the ground, no intermediary water loop. It's about 6 yars old, working like a charm in CT. Along with hydronic radiant on the 2nd floor, he keeps the (3000sqft) house at 75 and hasn't kvetched about electric bills ever! (And he is CHEAP)
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For the home - geothermal systems
