The heat exchanger on our old propane furnace is cracked. And propane is an expensive way to heat a home. Here, it is trucked in and pumped – so in the worst of winter, we’ve got to manage to clear the driveway so the delivery truck can get here safely. All in all, not sad to see it go. We’re comparing air-exchange heat pumps with geothermal heat pumps.

Obviously the air-exchange sales guy has a lot of terror stories about loop fields going bad, digging up the whole yard, and incurring tens of thousands in repair expenses. Our neighbor has a geothermal system and says he’s constantly using emergency heat so it’s really a super-expensive propane furnace.

I spent some time searching for the down sides to geothermal. Found a news article republished in quite a few small town news sites with a study claiming a town had so many geothermal installations that they caused their own localized warming. Suck heat from earth, pump to house to heat, lose heat through exterior walls … town heats up. Except all other heating sources extract an energy source from elsewhere, heat the house with it, and lose heat through exterior walls too. It’s not like we rip out our exterior insulation to get geothermal. If they’d wanted say the Earth’s temp lowered locally, it would at least pass a prima facie logic test. But they wanted to scare off the global warming types, so they went with “you’re causing global warming!!!”. And ended up with a completely illogical argument. If they wanted to talk about older, undersized, systems that created hyper-local problems caused the system to run on emergency heat … well, don’t undersize your system.

The only down side I’ve found is the installation cost and potential cost of emergency heat. We’re going to get the air exchange heat pump – the infinitely variable pump is supposed to operate in sub-freezing temperatures, and it’s a quick install instead of taking a month or two.