I am currently in the design stages for my home, and am trying to figure out what I am going to go with for my heating system. I am attempting to build it up to superinsulation standards  (r40 walls, r60 roof) where in some homes a conventional heating system is not even required.  However, since its difficult to source extremely energy efficient windows and doors, and i dont want to be too limited on certain architectural features, I was thinking of going with a small efficient heat source.  Since I have my own heavy equipment and plenty of land to run a horizontal system, i was leaning towards using a small gshp (1 to 1.5 ton?). Does anyone know of anyone doing something similar, and do small gshp's even exist?   I have looked at other options - solar w/ radiant,  ashp's, but i was realy attracted to geothermal due to consistent ground temps, high efficiency, and the ability to heat dhw when coupled with a desuperheater.

Smallest mainstream manufacturer units are 2.5 ton in 2 stage and 2 ton in single stage.

There may be other options - I believe I've seen smaller units down to 1/2 ton but I don't believe they connect to ductwork

Climatemaster had a Genesis in 15 or 18KBTU (don't know current availability) and a Tranquility 20 18Kbtu. Don't think 2 stage is too interesting if load is truly this small.
To that point we are way ahead of ourselves, what is the manual J load for the home?
Odds are a heating system is required by code in your area so going without is not an option.
If the load is as small as you suggest, you will have to take a hard look at op cost calcs before going geo.
Incidentally, this comes up from time to time. If you are able to do your own excavation, the most it will save you around mid MI is about $400/ton. It is often less than 10% of the job cost. Add in the lost tax credit and your price difference could easily slip under $1,000.
J

Advanced Geothermal ( which is DX )

starts at 1.5

http://www.advgeo.com/proddes.html

Looks like Hydron Module goes down to 1.5 ton too.

EarthLinked lists a 1.5 ton. I'm guessing, though, that any manufacturer listing one doesn't necessarily have it in stock, and that it's a special order item.

Just curious as you haven't responded nick, what is the manual J load calc for the home?
j

Sorry I am so slow replying to my own thread, but I was away this weekend and didnt have time to post. No i havent done a manual J load calc on the house. I know its probably always better to have a professional calculate it, but do you know of any free online sources that could give me a rough ballpark?

Here are a few specs on the home and let me know if you think it is far fetched to go with such a small system.

1800 sqft cape
Windows- Triple pain with U values of .2
Walls- 8.5" SIP walls w/ 1" XPS sheeting to eliminate thermal bridges
Roof- 4" closed cell spray Foam, 8" Cellulose, 1" XPS rigid foam to eliminate thermal bridges

Where (what city) is this house?

Nick,
I just completed a superinsulated house. We have a GSHP (two actually). One thing I did not consider prior to the commissioning of the house... the de-superheater is going to give you VERY little hot water because the system will not be running very much. I am currently investigating solar hot water. Feel free to contact me with questions.
Regards,
Ed

Jeez i forgot to mention one of the most important things about the house; its location! It will be located in northeastern CT... since CT is so small i doubt you'll need the exact city ;-).

Ed- Yea i was thinking that a desuperheater may not provide enough heat, especially if i am going with a small system. I am currently finishing a home right now that has solar heating via radiant. We havent fired it up yet, so i cant report how well it works, but I was considering going with a similar system for my dhw. Radiantec has a a package that consists of 2 solar panels, water tank, and all pre made manifolds for just under $4k. I dont want to go with solar & radiant for my personal home because unless you go with a slab, the cost and efficiency of the system goes out the window.
What are the specs on your house? Sqft, Insulation, windows & doors, size of heating system etc? It would be great to bounce ideas off of each other.

Nick

hello neighbor
I would push for a desuperheater , on the sole fact that it is required to be eligible for the 30% tax break .
I would say a PV system and electric hot water as the main source of hot water would give the best bang for porky buck

PV is CT is close to 75% paid for through state and fed credits

The most expensive part of geo is the looping so maybe it's not a bad idea, though on the other hand they say that those "passive" houses can be heated with the equivalent of a hair dryer so maybe anything is overkill.

Do a manual J. Versatec by waterfurnace has some smaller units.

I know of plenty of places you can get a man j done for $50 but not for free.

Hey geo fan, a desuperheater is not, i repeat not required to get the 30% tax credit!  In order to qualify you units must meet Energy Star rating.

Egouin, what kind of heat pump did you put in, the very little hot water should not be true.  When the unit is in cooling, you should get 100% of your hot water, when in heating, you should be getting about 80% of your hot water, something does not sound right to me here, give me some more info, by the way, did you do this yourself or hire someone in the industry?

Mkramer,
My understanding (and I've seen the language in the bill) is the DSH is required, I can't point you to it at this time, perhaps one of our other friends can.
Also a DSH only offers about 10% of unit capacity for hot water so a 1.5 ton for instance only provides 1,800 btu for hot water (when the unit is running). Even in july, you won't be filling the hot tub with that kind of production. Further as Egouin points out you only get the 1,800 btu when the thing is running.
J

Hate to correct you joe.ami but here is the link for the desuperheaters we use

http://www.fhp-mfg.com/newpdfs/HRP.pdf

maybe you need to buy a better desuperheater!

Also, go to the white house website, search for desuperheater in H.R. 1, it does not exist in 455 pages of legislation!

There is NO reqmt for a desuperheater, please stop putting out false information, you are hurting our industry.

Try again - the heat pump needs to meet Energy Star Criteria to qualify, which includes:

"In addition, some or all of the domestic water heating shall be provided through the use of a desuperheater, integrated demand water heater or a separately installed compressor that provides demand water heating."

http://www.energystar.gov/index.cfm?c=geo_heat.pr_crit_geo_heat_pumps

You're correct that it doesn't absolutely require a desuperheater, but it does need some form of water heating.

Hope it doesn't hurt the industry too much if one of your customers gets audited and penalized because they don't have any water heating capability!