Geothermal heating -- worth considering?

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Hello all -
I'm looking at homes in Central Pennsylvania.
A new one I will be checking out has the following: R-49 insulation, geo-thermal heating, solar panels.
How does geothermal heating work, vis-a-vis a "standard" hot air or hot water heat system? Do they actually save any money in heating costs?
These may look attractive when new, but what are the long-term maintenance costs?
Thanks, - John
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Your using the ground as a sink.
I thought about what if, after I had gas/air installed. If its installed, the big cost of digging or drilling is already done. All you got now is a Heatpump. These are likely to last as long as other air conditioners. Is it brand new ? I'm sure you will save money, but talk of increasing rates near Pittsburgh.
Greg
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John Albert wrote:

Hu, If initial cost is not a concern it is very worthwhile for the long term. It'll do both heating/cooling. In the 78's I looked at it when I was building my third house, bakj them I was looking at 25K for a typical residential house. I now think cost increased but also accompanying technology.
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On 9/25/2012 9:14 PM, John Albert wrote: ...

...
Like any other HVAC system, that will mostly depend on the type of system and even more importantly on the quality of the installation.
Well disposal system can expect more than a closed ground loop simply owing to there being another component (a well).
I had a Water Furnace (manufacturer brand) closed loop installed in E TN about 20 yr ago. AFAIK (sold house about 10-12 yr ago now) it is still operating as well as was when left w/ no issues since last talked to new owner about 3-4 yr ago.
It cut our electric bill compared to the air-air unit it replaced by at least 2-3rds.
--
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John Albert wrote:

In theory, geothermal heating (or cooling) pre-heats (or cools) the air to the temperature of the earth underground - usually about 56F. So, if the ambient temperature is, say, freezing, the air gets raised to 56F before regular heating kicks in.
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That is not how it works. Geothermal uses a HEAT PUMP. It's like a regular heat pump system, except that instead of using outside air, it uses water from wells or a ground loop providing around 50F constant temperature source year round. That makes it low on operating costs, but given the digging and installation involved, expensive on the initial install. I've yet to see one that could be cost justified, absent any unusual subsidies.
On the other hand, since it's already in a house he's considering buying, it could be a good thing if he gets the house at the right price and the system was correctly installed. I saw one a while back on Holmes where they had to install one all over again that was 3 years old because the install was done all wrong, but hopefully that is the exception.
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On 9/26/2012 7:55 AM, snipped-for-privacy@optonline.net wrote:

That's the way I would feel. Also I may not consider it a plus over other systems , that is would not pay extra for it. I have not investigated but some options for example an in-ground pool does not add to the value of a home. Just don't know about geothermal.
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On 9/26/2012 12:47 PM, Frank wrote: ...

That all depends like all real estate on "location, location, location"....in some local areas it would be killer to not have the pool in most cases.
You think it's not an advantage to have a heating system that's from 30 to as much as perhaps 65% less expensive to operate than conventional air-air heat pump in a northerly climate? Makes sense to me.... :(
Again, it'll depend on the various factors which weren't given/aren't available but as I noted above the ground-loop system in E TN (which isn't even very cold and has relatively low TVA electric rates) was a clear winner cutting our operational costs by about 2/3rds.
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On 9/26/2012 3:13 PM, dpb wrote:

I just don't know. Back in my short stint as a realtor quite a while back I had seen lists of home improvements and what a homeowner might expect to get back when he sold the house. I just picked the pool out of thin air as remembering it was a zero option around here. I'm saying I would not consider paying more for the house with this option.
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On 9/26/2012 2:37 PM, Frank wrote: ...

Methinks that's short-sighted attitude; things are different w/ energy costs these days and are likely to only get more so.
It's probably not a huge difference either way; the incremental cost of installation (assuming ground loop) is generally much less if it was part of new construction vis a vis a retrofit as our was since the dirt work can in all likelihood be accomplished in conjunction w/ foundation/basement/etc. rather than necessitating a separate exacavation period. Other than that, there's very little difference between the systems and the ground loop is in many ways simpler as the reject heat side is simply one small circ pump...
It's a feature in my book and suspect it's getting to be more so generically all the time and will only become even more of a feature w/ time...
--



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I generally agree that a geothermal system is probably an advantage to a house. But it also would depend on where the house is located climate wise and the cost of electricity there versus alternate fuels. Here in NJ with electric at 18c it may not look as good compared to nat gas as someplace where it's 10c.
And the age of the system and the replacement cost. I know a lot of the big cost is the outside part, but I wonder how much replacement of just the inside heat pump part costs as compared to replacing a gas furnace/AC unit?
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On 9/26/2012 3:39 PM, snipped-for-privacy@optonline.net wrote: ...

Well, of course, but the choice here isn't against competing systems for a new install; it's already in. Unless it was a case of a demo house or the like one would presume at least some of those considerations went into the choice.

Well, that's true for any system, whatever the type. Have you priced a hi-eff gas system recently? :) You also get "free" A/C w/ the heat pump--don't forget to add in the cost there in the replacement as well. And, if the A/C is used, many have the option of using the waste heat there for water heating that is another input energy cost reducer. In TN for the entire summer months and much of spring and well into fall the water heating was essentially free. Obviously that's not as big a deal as one gets more and more into more temperate climates so I'd not expect a unit in PA to have it.
I'm not saying it's always going to be the best possible choice or that even in this case it's a real plus but I'd surely think odds are it's a positive as opposed to run-of-the-mill furnace you'd find in the average house on the block for sale.
All in all, though, after my experience, I'm sold on the concept...
--
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dpb wrote:

A few things to keep in mind:
- Heat pumps in general are pretty efficient these days, and of course provide both heating and cooling.
- In heating mode, an air source heat pump becomes inefficient as the air temperature nears the freezing point. Ground source heat pumps don't have this limitation since soil temperatures at the loop depth don't get that cold.
- In cooling mode, an air source heat pump becomes inefficient when the air temperature gets above a certain point and the heat pump has difficulty dumping the heat it's moving into the air. Ground source heat pumps don't have this limitation since soil temperatures at the loop depth don't get that warm.
- Early ground source heat pumps relied on deep drilled wells or vertical loops or sometimes very long horizontal loops. More recent research has shown that these installation methods are not needed since the ground has a tremendous thermal mass. The new installation method is trenched vertical coil, where a large Ditch-Witch type trencher cuts a trench and the plastic tubing installed in a vertically oriented overlapping coil configuration. This takes far less installation space and less expensive installation equipment. Installers that are heavily invested in other technologies like drill rigs may try to persuade you to spend more for their method, but the scientific data show there is no benefit to the older methods.
- A loop is a loop is a loop, so in the event the heat pump needs to be replaced due to failure or to a higher efficiency model, it can be connected to the existing ground loop and thus have minimal installation costs. In the event the house is added on to and more capacity is needed, the existing ground loop may be large enough to accommodate a larger heat pump, or additional ground loop may be added to the system without the need to "throw away" the existing loop.
So, in PA, absolutely a ground source heat pump is a positive, especially if nat gas service is not available in the area and thus another relatively inexpensive heating option is not available.
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That depends on your definition of inefficient. In a thermodynamic sense today's heat pumps deliver more heat output even in the single digits than an equivalent electric resistance heater, which is 100% efficient. At 32F they are probably delivering at least 2.5 X the heat of a resistance heater. The total output decreases as well, which is a potentially bigger problem.

Whatever temp that occurs at, it's apparenty not a problem in a practical sense because AC works OK at 110F in Arizona.

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It's been over 30 years, but I remember people talking how it cost them per month for refrigerated air. Hundreds of dollars. What does it cost now in the desert ? It costs me roughly $25 a month in Pittsburgh. I know the units are a lot more efficient.
Greg
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On 9/26/2012 6:01 PM, Pete C. wrote:

Possibly, but others have mentioned "a heat pump is a heat pump"...

The current thinking at least in my area is to use wells with loops of tubing dropped in them because the heat you can get from burying the tubing in soil isn't enough for a typical installation (normal size property)

I am in PA know a few savvy people who could not get natural gas and ran the numbers and put in a ground source heat pump.
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George wrote:

Trenched vertical coil installation is effective on even small sub acre properties. If you compare wells to old style single tube long run horizontal installations certainly those obsolete horizontal installations required a lot of space. The TVC with it's overlapping coils puts that same loop length in a much smaller physical area which has more than enough thermal capacity unless it's a very dry soil with very poor thermal conductivity.

They are a good investment in northern climates, particularly with the less expensive TVC installation method which reduced the cost differential from other options.
Here in N. TX the climate is moderate enough that an air source heat pump works well. There are few winter days when the HP has to switch to backup heating, and in the summer there aren't many days when it's hot enough to have issues.
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The discussion was about how attractive a geothermal system would be to a potential buyer. The relative costs of generating heat from geothermal via electric as opposed to a system using natural gas are directly relevant. If the geothermal house can be heated for $1000 a year, while using nat gas in a similar house would cost $2000, then it's an advantage. If it's the other way around, then it's a disadvantage.

The specific issue I raised is what the replacement cost of a geothermal system is. I'm very familiar with what the replacement cost of a nat gas/AC system is. I have no idea what the cost of replacing the geothermal eqpt is. I'm suggesting that it might be a good idea to find that out. If it costs 2X, then that should be factored in together with it's age when considering if it's an advantage or not.
As for natural gas and AC, I think they are remarkably cheap for what you get. I bought a 120K BTU gas furnace and 5 ton AC for $4500 two years ago.
You also get "free" A/C w/ the heat

Obviously.
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On 9/27/2012 8:31 AM, snipped-for-privacy@optonline.net wrote: ...

...
I believe that's what I just outlined above--you (or others, I forget where in the thread all the sidebars on repair costs and all was actually introduced altho it may have been earlier) brought in the other factors and I simply added some points in those areas to consider...
On operating cost alone I don't think there's any way you'll find a cheaper source long-term...natural gas or no even given the present abnormally low n-gas pricing (that isn't going to last).
--
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On 9/26/2012 7:41 AM, HeyBub wrote:

Your heybub version seems to work a little differently than actual geothermal heating systems...
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