From what IÂve seen, the quality of components and construction IS better in some GSHPs.
The main reason for the high cost of the system is the drilling. This can be reduced by some 40% by choosing a DX GSHP.

Please see other posts relating to GSHPs in this and the HVAC forum.

SR

Here is a link that might be useful: how-efficient-is-it-magazine.com

SR,

Do you have any information on re-sizing you hydronic radiators? How much bigger should they be? I'm assuming if the original delt T is 60C and for GSHP we're looking at a delta T of 20C the area would have to be 3 times larger? Do you have any advice or web links?

I just bought a house (circa 1930) in MTL with an Oil Furnace and will be replacing the system with a DX GSHP in the spring. (No fund to instal right earlier) If I put in radiant floor heating, it would have to be installed from the basement under the hardwood flooring and it's not clear how effective that would be.

Keeping with the original post, retrofitting your existing system will definitely increase the costs.

Kungfu: I do not recall seeing that info on the web. However, since weÂre in the same city, if you e-mail me directly with your tel.#, perhaps I can be of help to put you on the right track. Mention ÂGeothermal as the subject so as to not get dumped in trash.

SR