geothermal questions and possible DIY

[LD1]

Considering putting in a geo system in the house I just purchased. Gotta do something. Only has electric baseboard heat and no AC.

So I called some contractors for some quotes. One came out today. Looking about $9k for air-air or about 18k for geo.

Both include ductwork which the house has none of. And the geo is with ME doing the excavation. $3500 is for ductwork which will be the same either way.

So air to air unit installed for $5500 vs geo for $14,500

Not sure what makes geo units cost so much? They both have compressors, and related parts. The geo adds a water pump and some outdoor plumbing, but $9000 more? Doesn't seem right.

This is just a preliminary quote from him just to get an idea of cost difference between geo and air to air. This is for 4-ton units too.

Just didn't think there would be $9k in material difference. Cause with me doing the digging, labor and ductwork should be nearly a wash in cost difference.

So...those that have made the decision and gotten quotes on geo vs a2a, what was the price spread for the furnace/unit itself?

Also, I know tbn is full of diy'ers. Anyone on here do one of them diy kits? And from where? How did you like it and would you do it again? I am considering this route as well, but not really something to get advise about from an HVAC contractor.

 

[s219]

I believe there is still a 30% federal income tax credit for geothermal. And it's calculated on the total cost of the system, so that would be about $5400 discount based on your $18K cost. In our case, it offset most of the extra cost of geothermal versus heat pumps. So look into that.

Federal Tax Credits for Energy Efficiency : ENERGY STAR

Without the tax credit, geothermal is a tougher sell. We are seeing an estimated 35% reduction in heating/cooling expenses per square foot in our new house with geothermal, compared to our old house with heat pump (and it's more comfortable and more capable). But even then, it would take quite a few years for the savings to offset the higher cost of equipment and installation. So the tax credit is a big deal.

 

[SPIKER]

My understanding of the two is that the A2A uses larger air exchanges & noisier than the geo. The biggest cost is digging wells OR excavation for the in ground tube & antifreeze in the tubes. The heat exchanger for the water to air is smaller than the A2A. Air just does not hold the BTUs of the water. The Vertical lines does not have to have the antifreeze materials in it as it spends most of it's time under ground at depth.

Addition of a wood fired heat exchanger would make it a LOT more efficient. Using burning wood to heat water store the BTUs back in earth to be extracted when fire is out.

Mark

 

[japody]

++ what s219 said. I calculated an 8 year payback period. Make sure you get the desuperheater. It's like getting free hot water. The highest electric bill we had for an all electric house last winter was $138. Also check to see if your state offers any rebates. Virginia only offers incentives for retrofits, not new installations. Good luck.

 

[buckeyefarmer]

I installed 2 units in my house myself. Take a geothermal installer class and you will learn everything you need, including how to fuse the HDPE pipe. Start with manual J calc for your house to determine the size, don't assume. Set yourself up as a business and set up accounts at geo supply house. I used Heatcontroller units, basically same as climatemaster. They come standard with desuperheaters and cu-ni coils. I used the non pressurized pumps, and headered inside. inside header allows you to flush with your loop pump, and it gives you full control over the loops, such as if one ever leaked, it can be turned off.

 

[LD1]

S219: I am aware of the rebate. I allthough it isn't 30%,of everything. Only things specific to geo. IE: duct work don't count.

But I do get an additional $1k from my local electric co.

But I refrained from bringing the rebate into this. Just symply trying to compare the base cost difference in equip/ material needed.

 

[LD1]

Spiker: digging ground loops is what I too thought was the most expensive to hire it done. But the 18k qoute, was me doing the digging. If I hired that out, its $900/ton.

So while I am saving $3600 digging a 4-ton myself. I just cannot believe the equip is 9k more than air to air equip

 

[LD1]

Also, I am not concerned with load calcs. I don't like the size units they end up concluding to. Too small IMO. I want something that will actually keep the house warm without the constant use of backup.

I don't like sizing for ac loads as most contractors like to do.

 

[dragoneggs]

Interesting thread... good luck LD. I have almost no experience but am eager to learn. Keep posting the design and build!

 

[s219]

S219: I am aware of the rebate. I allthough it isn't 30%,of everything. Only things specific to geo. IE: duct work don't count.

I don't know how it works for your situation, but for new construction, the 30% came off the top of the entire HVAC bill. They didn't itemize on the final invoice we got with the tax form, nor did the gov't ask me to itemize the individual costs when I did the paperwork with my taxes the following year (not sure how I would have even done it at that point). You can see the most recent tax form here:

http://www.irs.gov/pub/irs-pdf/f5695.pdf

Still looks like it covers the full system cost. Our total HVAC system cost included the geo unit, the well drilling, all interior ducting/dampers/etc, the de-superheater option, the hot water heater to go along with that, installation/labor, and a few other things. If I remember right, it was going to be $16-17K for dual heat pumps, or $27K for the geo-system. With 30% rebate, that came down to $19K, and was a reasonable leap. We have probably already recovered 60% of the price premium for geothermal by now.

So just because you're breaking costs down now, don't assume that's how the rebate works. If your house doesn't have pre-existing ducting and it's required for the forced air geo system, then that cost is most certainly part of the system. Same for trenching/drilling/installation.

Our HVAC installer, and the sub he used for geo drilling/installation, were both very knowledgeable about the tax rebate, and had gov't brochures and tax forms to share with me up front, when we were talking over the numbers. They use the rebate as a selling point for geo systems, otherwise far fewer people would buy them. So talk to the installer -- he should know the routine very well if he has done a lot of systems.