Geothermal heat

tis · 11-16-2010, 08:16 AM

I wish we could find out the true story about geothermal. We recently checked it out and NOBODY encouraged us to put it in. It seems it is expensive to put in and VERY expensive to maintain. We were told that it doesn't work that well. We were also told about people that took it out. So we just gave up. Maybe someday it will be perfected as will solar but until then we just have to stick with oil.

DickR · 11-16-2010, 09:26 AM

It's hard to believe all the disinformation in some of the posts so far in this thread.

"Worst case is forced air. You lose 50% of your heat in the duct work and intitial heating." This statement makes no sense unless you run ductwork in an unheated crawl space or unconditioned attic, without insulation around the ductwork, and without the duct joints completely sealed. All of that represents a poorly designed and installed forced warm air system, something totally unacceptable for a new home. If all your ductwork is within the conditioned envelope of the house, none is "lost".

"You still need backup." A GSHP (ground source heat pump, aka "geothermal") doesn't need a backup system anymore than any other type of heating system. Can it break and need service? Of course, as can any other type of system.

"It seems it is expensive to put in and VERY expensive to maintain. We were told that it doesn't work that well." Installation costs vary widely. There is no "typical," just as there is no "typical" location (part of country, terrain, rural vs. suburban, etc). For a new rural house in the northeast, properly designed to be very thermally efficient, if a well must be drilled for water anyway, then installation cost may not cost much more than a fuel-fired heating system. Maintenance of a GSHP typically is less than for a fuel-fired system. Like a refrigerator, it just sits there and runs for years. If distribution is by warm air, then filters need changing periodically.

Kimdaved, the first part of your house design should focus on making it very, very thermally efficient, possibly in the superinsulated class. That costs perhaps 5% more than conventional construction. We're only talking about the outer shell, mind you. Once you have a good shell designed, then think about how to heat the place. Having a very low heat demand makes GSHP that much more attractive, as the system is that much smaller.

Warm air for distribution of the heat is convenient, efficient, and lets you reverse the heat flow to give you A/C in the hot, humid parts of the summer. There are a number of good websites out there on GSHP. Do your research well, and don't rely on heresay.

Our situation is like yours, although we are further along. Old cottage, new house design. But ours is nearing completion. Yes, it is a superinsulated design, and the heat source will be GSHP. The well had to be drilled much deeper than the heat pump needs for the expected load, so the drilling part was essentially "free."

BroadHopper · 11-16-2010, 04:35 PM

PSNH will give you unbiased consultation in HVAC matters. Free of charge. Give them a call. A PSNH consultant went over the house to determine the best way to insulate the home for energy star rating. He will even recomend insulation contractors and inspect their work.

He will also give you guidelines as the best method to heat and or cool your home for this climate. Its a great service that I would recomend for anyone who wants local experience and opinion.

No. I do not work for PSNH. I am a very satified client.

ACutAbove · 11-17-2010, 06:02 PM

I installed a well system last yr for a client of mine at his waterfront home almost 7000 sq ft. It was a retrofit from his original oil burning system ( which we left in place for the hot water and as a back up system) Also in order to get the rebate from the CO OP you are required at that time to have a back up system. I will not go into numbers on the forum as to cost or actual savings with the system, but the pay back worked out to be about 7-8 yrs if I remember right. We also heat the indoor pool off the same system and the hot tub. The system works awesome weather it is heating in the winter or cooling in the summer. We used all quality components a have not had a problem with any of them as of now.
We also did a loop system at another house where we dug big pits and buried about 400 ft of 1 inch coils in the ground and do the heat transfer useing that method. You need to have a good amount of land to be able to do that type of system and on the water front there usually isnt enough.
If you would like to message me I would be happy to give you some info andpossiably answer some questions for you.

11-16-2010, 04:35 PM	#3
BroadHopper Senior Member Join Date: Oct 2004 Location: Laconia NH Posts: 5,570 Thanks: 3,206 Thanked 1,101 Times in 793 Posts	PSNH Consultation PSNH will give you unbiased consultation in HVAC matters. Free of charge. Give them a call. A PSNH consultant went over the house to determine the best way to insulate the home for energy star rating. He will even recomend insulation contractors and inspect their work. He will also give you guidelines as the best method to heat and or cool your home for this climate. Its a great service that I would recomend for anyone who wants local experience and opinion. No. I do not work for PSNH. I am a very satified client. __________________ Someday may never be an actual day.

11-16-2010, 08:16 AM	#1
tis Senior Member Join Date: Jan 2006 Posts: 6,709 Thanks: 751 Thanked 1,455 Times in 1,012 Posts	I wish we could find out the true story about geothermal. We recently checked it out and NOBODY encouraged us to put it in. It seems it is expensive to put in and VERY expensive to maintain. We were told that it doesn't work that well. We were also told about people that took it out. So we just gave up. Maybe someday it will be perfected as will solar but until then we just have to stick with oil.

11-16-2010, 09:26 AM	#2
DickR Senior Member Join Date: Apr 2008 Location: Moultonborough Posts: 750 Thanks: 4 Thanked 259 Times in 171 Posts	It's hard to believe all the disinformation in some of the posts so far in this thread. "Worst case is forced air. You lose 50% of your heat in the duct work and intitial heating." This statement makes no sense unless you run ductwork in an unheated crawl space or unconditioned attic, without insulation around the ductwork, and without the duct joints completely sealed. All of that represents a poorly designed and installed forced warm air system, something totally unacceptable for a new home. If all your ductwork is within the conditioned envelope of the house, none is "lost". "You still need backup." A GSHP (ground source heat pump, aka "geothermal") doesn't need a backup system anymore than any other type of heating system. Can it break and need service? Of course, as can any other type of system. "It seems it is expensive to put in and VERY expensive to maintain. We were told that it doesn't work that well." Installation costs vary widely. There is no "typical," just as there is no "typical" location (part of country, terrain, rural vs. suburban, etc). For a new rural house in the northeast, properly designed to be very thermally efficient, if a well must be drilled for water anyway, then installation cost may not cost much more than a fuel-fired heating system. Maintenance of a GSHP typically is less than for a fuel-fired system. Like a refrigerator, it just sits there and runs for years. If distribution is by warm air, then filters need changing periodically. Kimdaved, the first part of your house design should focus on making it very, very thermally efficient, possibly in the superinsulated class. That costs perhaps 5% more than conventional construction. We're only talking about the outer shell, mind you. Once you have a good shell designed, then think about how to heat the place. Having a very low heat demand makes GSHP that much more attractive, as the system is that much smaller. Warm air for distribution of the heat is convenient, efficient, and lets you reverse the heat flow to give you A/C in the hot, humid parts of the summer. There are a number of good websites out there on GSHP. Do your research well, and don't rely on heresay. Our situation is like yours, although we are further along. Old cottage, new house design. But ours is nearing completion. Yes, it is a superinsulated design, and the heat source will be GSHP. The well had to be drilled much deeper than the heat pump needs for the expected load, so the drilling part was essentially "free."

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11-17-2010, 06:02 PM	#4
ACutAbove Senior Member Join Date: Jun 2005 Location: Holderness Posts: 219 Thanks: 7 Thanked 9 Times in 8 Posts	I installed a well system last yr for a client of mine at his waterfront home almost 7000 sq ft. It was a retrofit from his original oil burning system ( which we left in place for the hot water and as a back up system) Also in order to get the rebate from the CO OP you are required at that time to have a back up system. I will not go into numbers on the forum as to cost or actual savings with the system, but the pay back worked out to be about 7-8 yrs if I remember right. We also heat the indoor pool off the same system and the hot tub. The system works awesome weather it is heating in the winter or cooling in the summer. We used all quality components a have not had a problem with any of them as of now. We also did a loop system at another house where we dug big pits and buried about 400 ft of 1 inch coils in the ground and do the heat transfer useing that method. You need to have a good amount of land to be able to do that type of system and on the water front there usually isnt enough. If you would like to message me I would be happy to give you some info andpossiably answer some questions for you.