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[Mr. Maple]

  Playing with the idea of getting a geothermal system in place,not so much for heating end as for cooling,temperatures here today broke 107 degrees!!!!!  Would the two systems work together in the wintertime,or would I be causing trouble with creosote issues etc due to furnace not having to do all of the heating?

[E Yoder]

We've tied into several geothermal (ground source heat pump) systems. Really not much different than tieing into a regular heat pump. You can trigger the blower with a second stat or break the compressor. Newer ones might be going the communicating route now tho. Then relaying signals can't be done. You'd want to check.
I would think you'd want to wire it to only run the geothermal as a backup but if you run simultaneously it'd be like spring weather as far as how it affected your OWB. Just don't load it heavy.
My thoughts anyway.

[shepherd boy]

  Playing with the idea of getting a geothermal system in place,not so much for heating end as for cooling,temperatures here today broke 107 degrees!!!!!  Would the two systems work together in the wintertime,or would I be causing trouble with creosote issues etc due to furnace not having to do all of the heating?

   Don't know if Geo will be cost effective for you, but they work well in conjunction with an outdoor furnace. Like Yoder has stated just don't go with a unit that utilities a communicator stat. You can still make your outdoor furnace do all the heating except for backup.

[wreckit87]

I've been looking into this too.... Planning on doing GSHP W2W system with PV solar in my new shop and LP backup/snowmelt. As much as I hate cutting wood and being married to an OWB, I think I'm going to put one in anyway to run when I feel like it. 7200 sq ft with 16ft ceilings is going to take some heat. A guy should be able to rig it the same way as a gas or oil backup right? Say the GSHP only kicks on when incoming OWB water is below 120 or whatever?

[schoppy]

The systems work just fine together. It is just a matter of what you want them to do size wise. I have 2 closed loop geothermal systems heating my house, one water to water and one water to air for a total of 9 tons. I added a 50x60x16 shed to my heat load so my geothermal systems were not big enough then. I purchased a G series Heatmaster to handle all heat loads and DHW, now my geothermal is my backup. About 2 months after ordering my OWB I found a Geothermal system on Craig's List with all components (same make as my home's) big enough for my shed for $2200 including an air handler for A/C if I want. It was one year old, the guy didn't like it saying it was too loud. When I'm sick of cutting wood I'll put in a loop field and put my shed on geothermal too.

The point to all this is that you can make both systems to work together. Slim was fantastic in aiding a newbie like me at the time to the OWB world. The controls were not that complicated to configure as I had extensive experience in HVAC and Slim helped me figure out the best method for tying in the OWB. If it were me, I would put in Geothermal big enough for anticipated heat and cooling loads for the day when firing up that OWB gets old or your body says enough. Just my 2 cents worth.

[Mr. Maple]

  Just waiting on dealer to come and give me his sales pitch and estimate,told him no hurry. Any forewarning on how high a sticker shock to expect?

[wreckit87]

  Just waiting on dealer to come and give me his sales pitch and estimate,told him no hurry. Any forewarning on how high a sticker shock to expect?

Oh so many variables.... Do you need a 2 ton system or 10? Water to water or water to air? Horizontal or vertical ground loops? I have talked to folks that ended up in the $30-40k range for a 3-4 ton A2W system with vertical loops. Then again I priced an 8 ton W2W system for myself with 2 different installers, both came in at roughly $45k with horizontal loops or $50k with vertical. Using the same equipment and doing all the labor myself brought that same system down to roughly $30k. Seeing as your boiler is huge, I might speculate you have a rather large heat/cooling load and the heat pumps themselves are quite spendy pieces of equipment. May want to be sitting down

[schoppy]

As I mentioned I have 9 tons total with 2 systems. I had 5400 ft. (600 ft per ton x 9) of pipe installed laid out in a opening 100 ft x 300 ft x 8 ft deep. My bill came to $40,000 but received 30% back in Federal tax credits to bring it down to $28,000. Not sure where the tax credits are at right now but reputable dealers will know. The estimated pay back for my system was 8.5 years at the prices LP was at when I put it in. Not sure about individual state incentives for geothermal.

One of the newer methods of installing loop fields is directional boring much like utilities use but it is still pricy. A friend is installing one of these right now, I think he has a 5 ton system costing him about $30k. If you have a pond or open water nearby that doesn't freeze solid, that would be the most efficient heat transfer method.