Re: Geothermal and radiant heating
Do you have natural gas? I think overall, you'd be better off with either a forced air gas furnace or a boiler. For old home retrofits, I like mixing high velocity heat pump system with a hydronic coil running off a regular boiler or a tankless water heater.
THe truble with geothermal in MI, is that you cooling load is a LOT lower than you heating. SO you end up over-sizing the system for heating and will have trouble removing humidity in cooling even with a 2 stage system.
I'd spend the money on comfort, than chasing marginal returns on effiency. Geothermal makes a lot of sense out in the country hen you propane it your only alternative.
1925 Two-Story Stucco Beaux Arts Neoclassical