benjamin said:Cal would tell me to keep my mouth shut, but on this site you get what you pay for. If you want somebody to tell you what you want to hear go listen to a politician.
Geothermal with a lake loop sounds great to me. My first thought was that it's hard to justify geo on dollars and cents when you compare it to mild passive solar with slightly improved insulation, but then you go and mention full log construction, so forget about low heat loss. Second thought was that trenches or wells might provide a higher source temp as the lake will get cold fast, not from your heat pump, just from winter. If the lake is 40 and the well water is 55 it might not be that big of a difference, especially since you can throw a lot more pipe in the lake easier than you can add more trench and you're probably going to be looking at a bigger system.
It's awfully nice to have air conditioning here in southern WI, even if we only use it a week a year, but then the radiant slabs would be nice also, I can't help on that one. Another nice feature is a water heating system, either desuperheater, or with a water to water unit that switches between heat and hot water. Again, I can't help with the cost or payback on this, just something to consider.
I've worked with FHP and Tetco, and haven't seen any problems with either in my limited experience.
I have geothermal. Why would I tell you to keep your mouth shut unless I actually thought you would?
Do you have geothermal? Do you install geothermal?