I'm in SE PA and about to have a geothermal system installed with a desuperheater. Talking to the engineer, the winter time expected closed loop temp will be around 35-40 degrees. City water comes in the house at around 50 degrees. At these low propane prices (I just filled up for $.76/gal), would it make sense to continue using propane to heat the water from 50 degrees to 110 in the winter rather than the desuperheater working "harder" to bring 35 degree water up to 110 degrees? Maybe I'm nitpicking a few bucks here and there, but with these low propane prices and it's ability to heat a lot of water quickly, maybe it makes sense to keep using fossil fuels to heat my water in the winter until those prices rise. Am I way off base here and not understanding the efficient nature of the desuperheater?