I'm no expert on GT except for the info I collected when getting ready to build our new home. Up north I'm sure the economic of it are much different than here in cent FL. It was not practical here because of the very high install cost ($30K+), a lot of this for all the wells...it takes numerous wells...you don't use your drinking water one...the driller sinks a casing and a 'loop' of pipe drops down into the ground. The system fluid is then circulated through the well loops in series to get the heating/cooling. The horrible truth is that there's going to be no easy way out for you souls up north if the cost of energy isn't reigned in. The hoopla about more oil drilling is such crap....I wish people would just critically think about what's actually happening. Coal and nat. gas prices have also doubled within the last year...we produce that ourselves, there is no shortage of them...All extra drilling will accomplish is put more $ in the pockets of the energy companies.

gary: thank you so much for your quick response.
Yes, we're pretty anxious about what this winter holds for us, whether we'll need a 2nd mortgage to just heat the house.

hmmm...you mention $30K, others stated about the same.
The News article that triggered the geothermal idea for us said something ~$15K.
So we're thinking
= $15K for geo
+ $7K for solar panels
= $22K

w/ the quick calculations of ~$450/month (AVERAGEd from peak of $900/month in winter to low of $200/mth in summer of heating/cooling costs), we could break even in under 5 years (not counting expense of the loan to pay for these).

But if it's more like $30K, is there another more cost-effective solution besides a pellet stove? (My daughter burned her hand on one at 1year old.)

Thank you,
Amanda

huango

You have to be careful when applying generalities like "$30K" to your specific site. I have a large GT system - 12 tons worth of HVAC. The total delta cost between that system and one with High Efficiency heat pumps was $15K NOT including the digging of the loop field BUT inclduing everything else. The extra costs for GT heat pumps over regular heat pumps is not a large delta. You would not need 12 tons of GT for a 2200 sq ft home - maybe 5 tons at most. My 6 ton unit was spec'd to handle about 4400 sq feet (2200 on the main level and 2200 in the basement that is mostly below grade).

The loop field is a big variable but there are many options. For a closed loop system you can use a pond (if you have one), a horizontal field (a pit), or wells. For an open loop system you can use a well BUT you need a place to dump the water that is pumped out (a pond or stream). This is where the costs for GT are very hard to estimate on a forum like this - you need to get several quotes for your site.

Here is some data that might help you that I got this from research my install. Use this as rough approximations, I live in the mid-Atlantic region in the moutains. For every ton of GT you need a 100 ft well and wells cost about 10 dollars per foot to drill. So if you go that route - and assuming you needed 5 tons of GT - you would need 5 x 100 ft wells and that would cost roughly $5000. You have to weigh that cost vs. the cost of digging a pit. For a pit you need a hole that is 120 feet long x 6 feet deep. The width of the pit is driven by how many tons of HVAC you have. With 5 tons you would need 5 loops - and each loop requires 4 feet of space so that would be a 120' x 20' x 6' pit. See if you have that kind of space on your lot and rememeber they will also need space around that to pile the dirt (and it's a lot of dirt - way more than you could imagine!). If your site is right - it might be cheaper to go with a horizontal loop field.

I too have been thinking about using solar to run my loop pump. My pump draws 7.5 amps at 240 volts which is 1800 watts and that runs 24x7. I would need a pretty big solar system to drive that and the cost right now is too high. However, I am going to keep watching and someday will hopefully be able to add that in. Perhaps with a smaller system you could make the the numbers work. I estimate that a solar system would save me about $75 per month off my electric bill - so I would need the solar system to cost around $10,000 to break even in 10 years. A 2 kilowatt solar system runs in the 20K to 30K range. You mentioned 7K for solar - that seems low but maybe prices have come down.

Another idea I had is to add in a contoller for the system so that the loop pump only comes on when the inside themostats call for heat or AC. This would allow me to turn off the loop pump when it isn't needed instead of having it run 24x7. The contoller has to be smart enough to anticipate trends in temps so it doesn't make the pump start & stop too often which would be a waste of energy too (it takes a lot of power to get the loop water moving). This might be a neat project to tackle once I get through all the other things I have on my ever grwoing list.

Before comitting to GT - you need to make sure that your house is well insulated and sealed from air infiltration. If you have a leaky house, you will not see the savings and the Gt system will struggle to keep you warm in the winter. GT systems are great but they cannot generate the BTU output as quickly as a gas or oil system can. If a GT system is overwhelmed, the emergency heat will come on (the heat packs) which is essentially a giant toaster and will run your electric bills through the roof.

I also recommend having some wood burning fireplace inserts or stoves to augment the Gt syetm when it is really cold AND most importantnly provide a backup if the power goes out.

best of luck.

Sniffdog, I think some of your numbers you used are different from what I am used to. Where I am (SE Pa) we use 150' of vertical borehole for each ton. The cost per foot is running around $15 a foot (wells, grout and pipe installed to house).
I can't believe your pump is running 24/7. That is the biggest waste of energy. All you need is a low voltage wire run from each unit to the pump and a few relays. When Y calls from any unit the pump starts. That is all you need.

huango- Do you have ductwork in your house now?

funny

I noted that they were rough approximations based on what I was going to be charged. There are many variables.

I like the idea of turning the pump off but it takes a lot of current to get the 290 gallons of fluid in the loop field moving. So during the summmer and winter when the AC or heat is coming on frequenctly, once the pump is on it is probably more efficient to just let it run.

However, during non-peak periods when the temps are milder and the AC or heat is cycling infrequnectly it would make sense to tie it into the tstats and start the pump when there is a call for it.

Can you recommend the type of relay device that can do this job? I posted on the Renewable Energy Forum a while back and found a micro computer based system that can monitor temperatures and is programmable - it is being used to monitor GT system efficiency. I could use a system like this to read room and exterior temperatures and write a simple program to decide when to turn on/off or just leave on.

For example, if the exterior temperature is below 77 (where I normally set the AC) but there was a call for A/C because the inside temp was higher than 77, then I could turn off the pump when the AC call was done. If the outside temp was above 77, then I could leave the pump running. Similar logic could be used in the winter time.

All I would need to do is tie in a relay to the contoller so I could cut power to the pump. Do they make 240 volt relays that can be activated by a DC low volatge input? if so, please tell me where to find it. Maybe I will move this project up in the queue.

Thanks

Sniffdog and funnycide:
Thank you very much for your inputs and guesstimates.

- So Ill need ~5 tons of GT.
- I need to learn more about open vs. closed loop systems. I have some land between my house and the neighbors where itÂs just trees right now (my husband wants to turn it into a SMALL soccer area for my Âhopeful soccer star 4years old sonÂ.) So maybe I can put a horizontal field/pit there, since I have no pond/stream.
- Can you plant stuff (trees/bushes) on top of the pit?
If I clear up the land for the pit, weÂll basically gave up a big reason why we bought this house: it comes with natural privacy from the neighbors. We have the 120Â by 6Â pit, but not the 20Â width with out having to take down all the trees, etc.
- So ~$5000 to dig the wells.
How much for the GT systems? Where can I read more about it? How many manufacturers make them?

- My neighbor mentioned he wanted to get solar panels and thatÂs where I got the $7K guesstimate.

- WHO can I contact/hire to tell me how insulated my house is, besides seeing how much insulation I have in the attic/basement?
Because the house inspector (before we bought the house) already told us that we need more insulation in the attic, which weÂll add asap.
- Thanks for the recommendation on the backup. We do have a fireplace that is in the center of the 1st floor.
Question: why should we get an insert? CanÂt we just burn the wood in the fireplace? Too much heat loss?

I had forgotten to add in my post that I do NOT currently have ductwork.

More questions:
- How do you retrofit ductwork into a house?
- The familyroom is an addition to the main rectangular house. ThereÂs currently a wall/doorway between the main house and addition. There is a crawl space under the addition. We plan to knock down that wall w/ the kitchen renovation. Also that family has cathedral ceilings.
So how do I get ductwork to this familyroom?
I donÂt want it in the wall, since itÂll be coming down.

Any knowledge of using GT for radiant flooring heat?

Again, thank you very much,
Amanda

I'm not sure how you decided on 5 tons. It's not terribly important at this time.
Adding ductwork to a house varies from relatively easy to really difficult and nearly impossible. A common procedure may involve having a unit and ductwork in the basement feeding the first floor through floor registers. A second unit is installed in the attic to feed the 2nd floor. This gives you good control but costs $. You might be looking in the $20k range to install 2 new systems with all new ductwork. This is without the added cost of a geothermal ground loop. You won't know until you get local bids.