I am building a new house.  I am paying extra for soy base foam insulation.  Do I still need geo-thermal for heating and cooling, or am I just throwing money out the window?  Will I regular heat pump( not a high efficiency) do?

That's way too vague a question to garner a usefully precise response.

We'd need to know your climate, heat and cooling loads, cost of alternative sources of heating and cooling energy to be able to even begin to estimate the payback periods / returns on investment for various system choices.

Has anyone calculated the ROI for the Soy foam option? Does the investment in it to avoid an extra half or whole ton of heating / cooling capacity pan out over time?

You need a manual J load calc performed as it is the only way to accurately size and compare life cycle costs, then we can advise accordingly. If you are at a loss on how to get a man J completed let us know...Eric

I have looked at purchasing software to do a manual J load but it looks involved. I think a am fairly intelligent. Should I pay a local company to do the calculation or is there a easier way? I live in Alabama, I don't think geothermal pumps are very popular down here. Thanks for your help.

I live in central Alabama so hot in the summer and just a few days in the winter where it does not get above freezing. I do not know what ROI is. The bid for the foam insulation state the 'R' is 3.81 per inch. Is that the same? I have figured out I need a manual J load calculation, which I will see about getting. The house will be about 3100 one level on a slab. I am kicking around the thought of radiant heat flooring also. The house is on a lake so we will use a closed loop system, that will be cheaper than drilling. I calculated an annual cost on my locate electric cooperative and the extra cost of installing the H20 geothermal does not pay off for 30 years at the current fuel and electric prices. I know these will go up but that cost is unknown. The cost we have been quoted locally for the H20 geothermal pump is $8500/ton with 6 ton unit. This includes domestic hot water and hot warm for radiant heat flooring( if we put that in). The quote for the installation of the radiant heat flooring was $30,000. This seems expensive. I am confused on what to do. Can you or anyone else give me words of wisdom? If I place all these "green" things the cost of my house goes up tremulously.

I'll let the geo pros comment on their end of things. The radiant however, I'll give you my 2 cents on.
For your cooling dominated climate, radiant has little to nothing to offer. In fact, you could very easily end up with a less comfortable home than you would with a forced air system.

With radiant in slab, you have this huge mass of concrete. It takes a long time to change the temperature, kind of like turning the Titanic. In a cold, north climate, this isn't bad. The slab keeps a steady flow of heat in to the space through the cold winter months. In a climate like yours, you'll be trickling out the heat, but if you get a sudden cold or warm spell, it will either take a long time to heat up or cool down.

There are control systems that can help somewhat, but you're working against physics, which is usually a losing battle. I would save the $30k and put it towards having a really good HVAC contractor work with you, do the manual J, design the system properly, and support it down the line. Put some of it towards more insulation, especially under the roof/in the attic. In your hot climate, you can't overdo the attic insulation because of the extreme temperatures that you're trying to insulate against. If you're getting R 3.81 per inch, then you want at least 10" thick, insulating all the wooden members as well to reduce thermal bridging.

If you have access to a building energy professional, they can help work through all these details, which will incorporate insulation, heating/cooling systems, windows, etc. You want to partner with one of these people early in the process because they can help pull all the pieces together and work with the specific subcontractors. Look for someone who is qualified to consult on EnergyStar homes or is a HERS rater. Their training and analysis software is greater than a generic energy auditor.

Good luck.

Thanks for your input.  The attic foam will be 5.5 from the bid. with the walls at 3.5. 

5.5" of R3.81 gives you R21. 5.5" is probably your stud joist as well, which, if true, means the total attic R value will be compromised to around R-16. The dept. of energy recommends R-30 to R-60 for attics in your area. There's a lot of debate about where you reach the point of diminishing returns.
You should definitely enlist the help of a home energy rater in your area. They'll be able to do these calculations and give you an idea of return on investment.

Did the geo co that gave you a quote do load calc or is it a house this size needs 6 tons type of thing
I would be skeptical of a geo contractor that doesn't use a load calc to size equipment.
Radiant can be aplied to your area if proper controls are used.
I would be leary of using chilled water in a high humidity area as dx will run 15 to 25 deg colder surface temp.
Variable speed fans and 2 stage compressor will help with comfort level and eff no matter what type of hvac system u go with
I would think u could add cellulose to the attic floor to get to r50
I would get other bids on radiant geo and insulation.

If you have ductwork in the attic, look hard at sealing the attic via closed cell sprayfoam under roof deck. Aged R value is R6 per inch, it adds considerable structural strength just now becoming recognized, and constitutes a vapor barrier. Bringing attic ductwork into the conditioned envelope can easily knock 10-20% off total load and renders duct leakage to almost a non-issue. Stack effect (air exfiltrating from high in home and replacement air infiltrating from low) is greatly reduced.

foam is pricey but much of the cost may be offset by lower installed cost of a smaller HVAC system, geo or otherwise.

The better the house is sealed , the less HVAC you need. So going green is an investment. Pay now so you don't pay later. As long as you are not flipping the house, invest in improving the structure even if you have to forgo the granite

I live in Texas. The Dallas / Fort Worth area. I have been a foam installer for 10 years now. The company I work for has his LLC bond. I have a license for installing from SPI. This "Green" Soy based product is not as green as one would think. The energy used to extract the chemical used as a base in the foam making process is unreal. How ever. yes, rigid foam is only considered an R4 per inch. But the DOE considers it at a 98% efficiency rating. That should actually make it an R 11-12 rating. A radiant barrier is only an aluminum based paint. It is only good for blocking UV radiation. It does NOT seal your home from air infiltration. But, Rigid and ONLY rigid foam does. Here we only have to use 2" in the walls, and 3" in the ceiling. As a matter of fact. I have sprayed the liquid oxygen fuel cells for space rockets for SapceX. They only require 3". When the rocket is launched, the fuel cell gets to -390F. The big orange fuel celll on the space shuttle only has 3". Same as before, during launch, it gets to -390F. If they government only need 3" on something like that, and you put that in your home, it will be WELL insulated! If your home is completely sealed with foam insulation, you will have to work well with the HVAC installer. You will actually need to install 1/2 the normal tonnage, and a fresh air system. Oh, and I also have my EPA license for HVAC. Now, back to the "Green Foam". It's not really all that green on the environment. But, insulating your home will make it green, even to the point that your home will become energy star rated!

lgcurls,

Where are you building in central Alabama?  I live in Auburn, AL.  Just wondering if your site is close to Auburn.  By the way, I guess you are aware that I donate my time to interesting projects so feel free to send me questions.  My e-mail address is listed below.  This free offer is also available to anyone thinking about building in my area.

Be aware that some green products are green only in name.  Be sure to get value for your money.