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Kevin Bourque
03-08-2013, 12:31 PM
I was just at my sisters house where they have recently installed a geothermal heating/cooling system. Does anyone have a system like this in their home? Pros/cons?

Stephen Cherry
03-08-2013, 12:47 PM
Geothermal heat pump? I don't have one, but a while back I was talking with an hvac guy who had installed a bunch of them. He said that they are great, but home builders do not install them because of the extra install price. I have a friend with one that heats the pool with the ac; he swears by it.

David Weaver
03-08-2013, 12:52 PM
BIL installed one two years ago (about $20k centra pa, house already has forced air). His only other choice was propane and his supplier was nailing him to the wall on the price.

I think his heating bill has been quartered or less. Last year, he added hot water on to that, too, though he said it doesn't heat water quickly, so he added a second holding tank into the loop for it.

George Bokros
03-08-2013, 12:53 PM
My brother and sister in law have it and like it. They also preheat their hot water with it. The thing that surprised me is that the hot water tank failed at ~ the five year mark, seems soon to me. It cost ~$2,500 to replace.

George

David Weaver
03-08-2013, 1:08 PM
I asked BIL about that, too, and he said that the main pump of the system has a fairly long warranty on it - like 10 years or something. But the water heater of his doesn't. It seems like with the water heater, it's a principles issue and not so much a cost savings. Maybe it's a cost savings vs. electricity, I don't know, but a plain unforced draft water heater with NG is *very* cheap to buy, run and replace.

Mel Fulks
03-08-2013, 1:35 PM
I think it's one of those things that should start with "I wonder if that would be a good idea for this property" not "I want one". We had a case in this town where a couple building extremely large house wanted geotherm and bought .They refused to let the contractor install it in the location he said was necessary . Didn't work and they sued contractor .Dont know who won. I know of one that works and uses a deep well. Some say that is a waste of ground water.

Brian Elfert
03-08-2013, 1:37 PM
I've looked into geothermal multiple times. I got a price quote of around $25,000 for a complete HVAC in a new house with geothermal. A good HVAC system with central air and natural gas furnace for same house would probably be around $12,000. If/when I build a new house I really want to have geothermal. I figure a 15 to 20 year payback on the extra cost. The loop field should not need to replaced for many years if ever. Replacement of the other parts should be no more often than a traditional furnace and air conditioner.

Some incentives for installation of geothermal require a water heater as part of the system. There is a federal tax credit through 2016 that pays 30% of the cost so the payback is even sooner,

Greg Portland
03-08-2013, 1:37 PM
Carefully do your own math. It is unlikely that you'll make back the additional cost of the installation unless there are large local subsidies.

Jim Stewart
03-08-2013, 1:39 PM
I have had geothermal heat for 25 years. I live in an 1830's house that I have redone. I have had to install one new compressor in that time. I am sure that I have gained by having this unit but I cloud the situation by using a wood stove as well. At the time I installed mine there were not too many options. We do have natural gas in the ground here but no access to the commercial lines. At the time it would have cost me as much to drill for gas as it cost to install my Geo-system. Newer heat pumps as much more efficient both in Geo and Air-to-air. A builder is not likely to install the most expensive system in either air-to-air or geo. The hot water deal is simply gleaning heat off of the compresser to heat your water. This is only practical if you hot water heater is very close to the heat pump unit.
Plus side Geo:
very cheap air conditioning, cheap heat by pumping heat out of 55 degree temps, no outside heat exchanger (I really like the quiet)
negative side:
high initial cost of ground loop, When outside air is above 55 and you are better off with air-to-air

Nat gas is still the cheapest if you have access I think. They do make a dual fuel that uses Nat gas below say 40 degrees and then uses the A-T-A heat pump for above 40 and for AC.
Don't know the payoff time for either type heat pump but you electricity supplier can likely help you with that.

David Weaver
03-08-2013, 2:13 PM
It is unlikely that you'll make back the additional cost of the installation unless.

Compared to what?

Matt Meiser
03-08-2013, 3:19 PM
Supposedly the highest efficience air-air heat pumps are approaching the efficiency of geo. When you could get a 30% credit on the full cost of geo, they were similar in price. If that's expired, its a different story.

A co-worker put in geo that's a a trenched system in the fall. Excavation contractor did a poor job backfilling and they've got major settling. His ground loop temperature differential is almost nothing because they estimate there's only a foot or so of cover in some spots. He's getting month after month of the highest bills they've ever had due to the system using emergency heat all winter and they can't fix it due to snow pack.

Brian Elfert
03-08-2013, 4:50 PM
Supposedly the highest efficience air-air heat pumps are approaching the efficiency of geo. When you could get a 30% credit on the full cost of geo, they were similar in price. If that's expired, its a different story.


Would air source heat pumps work in a climate where it can get down to -20 degrees at times? I know they can work at lower temps now, but it seems like they have to work harder the colder it gets. I would probably want to have a gas furnace as a backup.

Chris Padilla
03-08-2013, 5:12 PM
Slightly related to this but I need to replace my trusty old NG water heater soon. I'm going with an electric model that includes a heat pump. My local utility and the Fed are greasing the way via $800 in rebates/incentives so I'm going for it. Of course, this heat pump is air to air and I'm in a mild climate here in the Bay Area so it makes a lot of sense to me to use one. I also have PV solar on the roof along with passive solar heating for the pool water. I guess I don't have the water heater yet so I can't comment on the savings or pay back or but I expect to have my money back in 2-3 years easy...thanks to the rebates.

Lee Schierer
03-08-2013, 5:21 PM
I've heated my hose with a geothermal heat pump for over 30 years. We live in NW PA and we get a full cold winter. We heat/cool about 2200 sq ft our total utility bill is about $1300-1400 per year, which includes conventional electric stove and conventional electric hot water. The house stays at a constant temp no matter what the temp outside does. It is clean and quiet. We updated our system about 5 years ago to a heat/cooling unit. We turned on the A/C July 5 and kept the house at a constant 74 degrees all summer and used the same kilowatts that we had used the previous summer running ceiling fans and a dehumidifier in the basement. Our new unit (50,000 btu) cost about $6800 installed, but we already had the two wells for the heat source.

Our payback on the initial system was about 8-9 years and there were no subsidies. The 30% federal tax credit is a really good deal. It is supposed to be in effect until 2016. There are also rebates being offered by some electric utility companies.

Currently there is a 30% tax credit for geothermal systems which makes them competitive to conventional systems. Even the new high efficiency conventional heat pumps won't work at temps approaching and below 0. The way they work is to energize resistance heating strips outside and then use the heat pump to capture the heat.

Our house started with baseboard electric heat. We added about 50% more area to the house and installed the geothermal heat pump at the same time, but our electric bill stayed the same and the house was more comfortable.

With a constant 50-55 degree heat source from the earth geothermal systems are highly efficient. In our area there are only two contractors that install systems. Other contractors hire these two to install systems in new construction with a mark up of course. If you are considering a system shop around. Climate Master and Water Furnace are two manufacturers. Their units are also labeled and sold as Carrier, Bryant and others.

Matt Meiser
03-08-2013, 5:40 PM
Would air source heat pumps work in a climate where it can get down to -20 degrees at times? I know they can work at lower temps now, but it seems like they have to work harder the colder it gets. I would probably want to have a gas furnace as a backup.

We put one in a couple years ago and they installed it right on top of our existing (about 2 year old at the time) 90-something% furnace. The thermostat is smart enough to watch the outside temp and when it gets below the tipping point, which I forget where ours is set but I want to say upper 20's, it uses gas instead. Our climate is a lot different than MSP, but its not very much of the year that we don't spend a good part of the day at least above that point. When its too cold we are still using an efficient gas furnace. Because of our existing furnace we couldn't go as efficient as I would have liked without replacing the furnace again. The payback just wasn't there for that option. I'll never hire the company that sold us that furnace again as I think they really steered us down the wrong path. Coincidentally my parents did for their recent remodel and I doubt they'll ever use them again either. The company has been around something like 110 years but the refuse to move past their old ways.

I don't have a good feel for cost and savings with ours as we made numerous changes the same summer. In one summer we got rid of a hot tub, converted to natural gas from propane, went from an electric stove to gas, and installed a heat pump. For gas our usage generally ranges from summer baseline (hot water, stove, dryer) to about double to triple in a typical winter month and that includes whatever I use to heat the shop to 42 degrees 24-7, 62 degrees several days a month, and 70 degrees a few days here and there for finishing sessions. Our electric bills stayed about the same as before, but in addition to getting rid of the hot tub we started keeping the whole house 68 degrees all day instead of letting it fall back during the day and just using a space heater in my office. Before that we were using about $1500-2000 worth of propane every year.

Back when I was looking at them, there were a couple people in your region who had them.

phil harold
03-08-2013, 7:57 PM
disadvantage

When the power goes out your out of luck

passive solar is the real answer

David G Baker
03-08-2013, 8:10 PM
Something I have not heard mentioned is Geothermal system using ground water in an area that has very hard water. My neighbor had a system installed when he built his new house. The installer did not test the water for hardness. The unit worked fine for several months then started to fail. Evidently the system was getting clogged with iron and other minerals. I haven't talked to him since he had a water softener and filters installed but I guess that took care of the problem. If I had one installed I would want the closed loop type where a hole is drilled to about 300 feet deep, a well casing in installed and a plastic pipe is looped down into the well and looped back to the heating unit.

Jim Stewart
03-08-2013, 8:43 PM
An air source must use an electric resistance coil and pumps heat from that at lower temps. Somehow using a small resistance coil is still more efficient. Most systems have an electric back-up as well if they cannot produce enough heat from the exchanger. My units have that system but they have never come on. For colder climates I have to think the geo units would pay back fairly fast.
A comment was made that Air-to-Air are getting more effecient. I would say the same thing is true for Geo. I installed a second geo unit to an addition I built about 8 years ago. That unit uses a 2-stage system so it runs a lower pressure scroll compressor during easy heating and the cooling cycle. That unit is a 27 SEER unit.

Mel Fulks
03-08-2013, 8:52 PM
David ,I'm sure there's a way to do those wrong ,too. Once all the problems are worked out ,geo therm will be old hat. My house has solar water heating panels that were installed in 1983 . Work beautifully and obviously save us money.They were on when we bought the place. But if we were to try to sell real estate agents would want us to remove them. They would not like my reply. The fact that they are paid for and an asset to the house means nothing to a savvy agent. Things have to be NEW.

David Weaver
03-08-2013, 8:57 PM
IIRC, the mixture that's in BILs is not water, but something with antifreeze in it instead. I guess that would be partly water, but it's only hard once unless you have to replace it.

Matt Meiser
03-08-2013, 9:37 PM
Right, most are closed loop systems. The wells are just a way to get the loops deep. The one they did recently on This Old House they even pumped the wells full of grout after they installed the loops. The other options are digging a big pit or long trenches. If we'd done it, we'd have gone with one of the latter since we've got plenty of room and its significantly less expensive.

Our 3 ton heat pump starts on our 12KW generator no problem BUT...burning nat. gas to make electricity to run the HP to make heat can't be the most efficient way to go so when we recently had an outage I switched to emergency heat and just burned the gas for heat.

Lee Schierer
03-08-2013, 9:39 PM
disadvantage

When the power goes out your out of luck

passive solar is the real answer

Same is true for gas and oil heat systems.. and the sun doesn't shine in northern climes for days at a time nor at night.:rolleyes:

David Weaver
03-08-2013, 9:40 PM
Yeah, passive solar wouldn't work well here. Too many houses behind treelines or in the woods, or on the wrong side of the hill. Too many days of clouds, too.

It'd be a fine experiment somewhere that doesn't freeze often, though.

Lee Schierer
03-08-2013, 9:43 PM
I doubt that they are softening the water they run through the heat pump. Most systems use 6-10 gallons per minute which would require a huge softening system. Our water is hard and has some iron content and our heat exchanger never had a problem and it ran for over 25 years before we replaced it to get a heat and A/C unit. There were instruction for cleaning the heat exchanger annually that came with our original Tetco unit.

Mel Fulks
03-08-2013, 10:00 PM
Freezing doesn't bother it . We also have a built in fire place grate made of water circulating pipe .when there is a fire water can circulate thru a coil installed at air handler to heat whole house . Until temp goes below about 28 degrees I can heat whole house (1600 sq feet )without using heat pump. Even HVAC guy likes it .This is the only one he has ever seen. It's not high tech enough to get popular. I save all the electric bills ,when we decide to sell they will be piled on the kitchen table.

Mel Fulks
03-08-2013, 10:09 PM
I know of one geo system that just throws a stream of water into the air the whole time .

David Weaver
03-08-2013, 10:54 PM
Freezing doesn't bother it . We also have a built in fire place grate made of water circulating pipe .when there is a fire water can circulate thru a coil installed at air handler to heat whole house . Until temp goes below about 28 degrees I can heat whole house (1600 sq feet )without using heat pump. Even HVAC guy likes it .This is the only one he has ever seen. It's not high tech enough to get popular. I save all the electric bills ,when we decide to sell they will be piled on the kitchen table.

Actually, I meant if it gets to be zero degrees or less like it gets here a couple of times a year and something else in the house freezes, and not the solar system.

I can never tell what people mean by passive solar, if they mean something like the earthships, or if they mean something like the rooftop water heaters. We just don't have a very good quantity of sun in the appalachians and it's not uncommon to have a week of temperatures that don't get above freezing combined with a lot of cloud cover.

http://www.currentresults.com/Weather/US/average-annual-sunshine-by-city.php

This chart sort of tells the story. A little east of here around somerset/johnstown it's worse, and it's colder there. I guess buffalo is the worst on here, and johnstown/somerset is probably similar because it's worse than the city.

Plus we've got cheap natural gas coming out of our ears.

Mel Fulks
03-09-2013, 12:06 AM
It is possible for collectors to freeze up if not correctly set up. But it seems I misunderstood you.We get plenty of cloudy days but for winter ,the fireplace component works well. The only drawback is when you do lose current you need to break up the fire because the pumps stop running. Loss of current in summer doesn't seem to hurt the system. I'm not saying its the greatest thing in the world. I do say that once the newness wears off in this society efficiency doesn't count much.I measure efficiency by keeping accurate records. Not by an ad or someone telling me I will have to tear out something that works in order to sell my house. I've heard guys who installed solar in the 1980s call home repair radio shows and say they didn't know what they were doing and the systems were worthless. Says more about their carachture than it does about the systems. You do need a long lasting roof.

Ed Aumiller
03-09-2013, 8:25 AM
I installed a geo-thermal system in my house in 1994, it both heats & cools the house... used ground loops consisting of 4 loops connected in basement in parallel, each 700' long, total of 2800' of 1" black plastic pipe buried about 5' deep.. 3 loops are in one ditch, 1 loop is separate ditch... put RV type antifreeze in system so if there is ever a leak there will be no problem...

One item to remember is when you put in the loops if using black water pipe is to keep all connections INSIDE where you can get to them.. I know they say that when the pipe is thermally welded it is the same as one solid pipe.. WRONG.. my neighbor has his loops in the bottom of a pond (works great) except one weld failed and he had to have it fixed...

Did not install the auxiliary strip heaters because heat pump is large enough to provide ALL the heat needed...

Five years ago installed same basic setup in house built for my son... but used 4200' (7x600' loops) and put the loops in coils underground (we dug ditches 4' wide, 30'long, 4' feet deep, layed coils down, covered with dirt).. on his unit, when he runs the A/C in summer, the heat from the compressor preheats his hot water for a normal electric hot water tank... did not install the auxiliary strip heaters in his house either..

Did all the work myself on both houses... Bought his unit off of a company in Florida via eBay, on his house the main unit cost $3300, pipes about $600, circulating pump and misc plumbing about $300, ductwork about $300, RV anti-freeze $500 TOTAL COST $5000 not including labor...

If you can do woodworking, you can install a system yourself, it is not hard... if retro-fitting a house with forced air, simply use existing ductwork..

Matt Marsh
03-09-2013, 9:14 AM
A lot of factors to consider when calculating payback. Your location is a big one. A "full cold winter" in PA is a might different than a full cold winter in Northern MN. You also have to consider your particular property with geo. A yard full of large, 200 year-old White Pines is going to effect your overall cost and plan differently than if you have a open area, large enough for the loops. You can do horizontal boring, but it's expensive, and generally requires even longer runs. Even if your house already has FA ducting in place, the duct size is often not large enough for heat pump applications. Check your state and local regulations relating to ground water systems, it may not even be an option where you live.

I got a couple bids for a ground water system from local contractors here in Northern MN in the mid 90s for my 1600 square foot house. It was around $18,000 to $20,000 then. At the same time I could do a top of the line 92% efficient propane furnace for around $2500 installed. I figured $16,000 plus could buy a lot of propane, even when figuring the same life expectancy/maintenance for both options.

When my central AC unit needs to be replaced, I'll definitely be checking into replacing it with an air to air unit. I already know my ductwork is too small, but so is my house, so it shouldn't be a huge expense to replace it.

Brian Elfert
03-09-2013, 9:31 AM
I don't think open loop systems are even legal in the state of Minnesota any more. I know new commercial open loop systems were outlawed in the late 90s and they all had to be replaced by 2012 or 2013.

My current house has natural gas heat and central A/C that were installed in 2001 when the house was built. Since my house is newer it has to meet some pretty strict energy codes. For a 2,700 square foot home I pay about $1700 a year for both electric and gas combined. If I thought I wanted to stay in this house long term I would consider geothermal before the tax credits expire in 2016. I run the A/C at 75 degrees all summer long from about June 1 to about Sept 15th. I don't open the windows because some sort of bugs come right through the screens when I do.

David G Baker
03-09-2013, 11:22 AM
Brian E.
This is off topic but may help you with your bugs coming through your window screens. There is a screen called "NOSEEUM". The screen is not well known even by window installers. The mesh on the screen is much smaller than most of your standard screen. Do a Google search to get the information if you are interested. I am slowly having my windows replaced and when I replace them I demand the noseeum screen. I could save some money if I had just the windows that I open for a cross breeze have the noseeum screen on them but I have it on every replacement. I still get some of the tiny critters that like to bite or suck blood in my house but I think they come in on clothing or through doors when they are opened. The only way I can see them is when they fly past my computer screen. They are tiny.

Brian Elfert
03-09-2013, 12:52 PM
Brian E.
This is off topic but may help you with your bugs coming through your window screens. There is a screen called "NOSEEUM". The screen is not well known even by window installers. The mesh on the screen is much smaller than most of your standard screen. Do a Google search to get the information if you are interested. I am slowly having my windows replaced and when I replace them I demand the noseeum screen. I could save some money if I had just the windows that I open for a cross breeze have the noseeum screen on them but I have it on every replacement. I still get some of the tiny critters that like to bite or suck blood in my house but I think they come in on clothing or through doors when they are opened. The only way I can see them is when they fly past my computer screen. They are tiny.

I have Andersen Windows and they do offer some fairly new screens that have stainless steel mesh to keep out the smaller bugs. I haven't done it because of cost and being lazy I guess. I can get Andersen accessories 50% off, but they still aren't cheap. The cost of running the A/C all summer long just isn't that much for my house so I haven't worried too much about it. Maybe this will be the year I buy the screens.

Mel Fulks
03-09-2013, 1:15 PM
Monticello has some tunnel thing that brought ground cooled air in during summer. They don't make a big deal of it ,but if you ask,they will tell you where to see it.

Greg Portland
03-11-2013, 5:43 PM
Compared to what?
Compared to other efficient options. I'm saying spend a few hours with Excel before you drop $10k+ on -any- HVAC system. You're not going to "make back" $25k but you -might- make enough to pay back the cost delta over a high efficiency gas furnace and heat pump. For my locale it made sense to spend $4k more for a high efficiency option but it didn't make sense to spend $14k more for geo thermal. Climate and house construction makes a huge difference... definitely run your own numbers.

David Weaver
03-11-2013, 6:41 PM
It pencils out for BIL. IT wouldn't for me. I heat 1600 sf for about $750 a year because of my locality to cheap gas.

My BIL heats closer to 4k sq feet and it was costing him about 3k or a little more on propane. His total installed cost was 20k (for a system that has three vertical wells as opposed to lateral) less whatever credits were available, so I guess it was about $14k.

I don't know if it also makes his A/C cheaper, I guess it probably does.

His price might be a little cheaper than you can get it done in Oregon, that's the magic of mennonite owned businesses where he lives.

David Weaver
03-11-2013, 6:42 PM
Monticello has some tunnel thing that brought ground cooled air in during summer. They don't make a big deal of it ,but if you ask,they will tell you where to see it.

This always seemed like a logical thing to do to me. When I was little, I used to wonder why you couldn't just dig a hole in the ground and blow air through it. I guess it's technically not quite that easy, but I sure wish it was.

Brian Elfert
03-11-2013, 8:24 PM
Air conditioning is also cheaper because the ground is usually around 55 degrees which is a lot cooler than outside air when air conditioning is needed.