Considering Geothermal. Already have a 3KW PV system.

I have a 25'x25' Cape with full dormer front and back with a 20'x20' single story addition. The main house has a full basement 25'x25'x 8' walls with concrete floor. The addition crawl space is 20'x20'x4' walls with R13 insulation and a concrete floor. There is no insulation in the floors above in either space. I currently have OIL FIRED STEAM HEAT in the main house and hot water baseboard in the addition, using the boiler water.

Ceilings        625' R20
                    400' R30

Walls            840' R13

Glass            210' R2   STD. Double glaze 1/2 space

3 Solid Entry Doors with storms

6400 degree days Hartford CT

My preliminary calculations concluded.

0 degrees - 36000 btuh
10 degrees - 31000 btuh
20 degrees - 26000 btuh

What temp do I design for?
What size closed loop WSHP?

I will keep the entire heating system in place for back up.

Thanks, Paul

My heat loss program lists 7° as the design temp for Hartford. If you use 20° then your system will cost less but you will use your backup system more.

If you are hooking your heatpump up to a closed ground loop then you need a GSHP, if you are hooking up an open loop on a well then you would use a WSHP. The heating capacity of these two types of systems are different.

Since your other post asks about ground loops I am assuming that is what you are planning.

Also heating capacity varies by manufacturer and model.

A Climate Master Tranquility 3 ton unit has a heating capacity of 25,800 while a GS 3 ton unit has capacity of 26,700.

A Hydron 3 ton H series has capacity of 31,600 while a HC series 3 ton has capacity of 32,000.


So it really depends on which brand of heat pump you want to install


Hope this helps

geodean you use Hydron Module???

Yes

GeoTemp Services: What's wrong with Hydron Module?

Nothing at all I know them well Im a GeoComfort distributor. Same manufacture.

I live in northern Hartford County and I am considering a geothermal heat pump... My heat loss calculation for a older ranch with a (1999) Cape type addition, fluctuated with the program used. I have a total of 2200 sqft. on a full basement. The heat loss calculations ranges between 39,000 btu and 59,000 btu. The diy website that I have been talking to says a 4 ton unit would work and I could keep my newer Oil fired hot air system as an auxiliary. My problem is loop type. 4 "slinky coils" will fit but I have to clear brush and trees on the back of my lot... I guess my issue is, can you really do this yourself. I have used a back hoe to build a patio but not sure about the plumbing or how much of a pain in the but will the digging be.... But the $$$ savings is impressive. Raw materials alone about 10K vs. 20+K for a vertical system, I have not been able to find a contractor for horizontal systems to get a quote...

Please don't do it yourself.

As someone else stated on this site, those who diy typically post here with something like: "I installed my own system....help!"

It's certainly not rocket science, and there may be parts of the system you could do just fine. But I would recommend not opening that can of worms. Bad installations give geothermal a bad name, and you're much better off with a properly installed oil system than a poorly/wrongly installed geothermal system.

If you want to save some money find someone who will do the install, but allow you to do things you’re comfortable with. If the contractor says he needs a 250' trench dug and then later buried and you can do that, that alone will save you a bundle. Some of the other things you might be able to do yourself as well. But I would agree, have a contractor or someone in the business be the "general".

I havn't posted in a while. Can anybody tell me if 8 100' deep holes in solid red shale, and 3/4" U Tubes, be a large enough loop field for a Climate Master Ultra Series (VT) 3 1/2 ton 2 stage GSHP? I believe it's actually larger than required.

it sounds about right to me. 200' of bore hole per ton is the about what it takes.

Tuffluck, I did not do the GeoThermal myself. I found, after trenching about 6 ft. , Huge bolder after Huge bolder. So instead, I went with plan B.... A pellet stove, installed by a pro. and a solar hot water heater installed by me http://www.greenbuildingtalk.com/Forums/tabid/53/forumid/15/postid/40005/view/topic/Default.aspx The wife even said that the geothermal was way over my head....