[brk-lnt]

I think there is a lot of confusion, and sometimes misdirection, around where geothermal systems are, or are not, applicable.

The basic concept behind a geothermal system is that it is able to remove heat from ground/groundwater. Any object that is not at absolute zero has *some* retained heat, and that heat CAN be removed from the object. The question is around the time and effort required to do so.

So, at the very least there is really no habitable area of the US where a geothermal heating system could NOT be used, though there are certainly many areas where the practicality of it could be very questionable.

Geothermal systems in NH appear to be relatively costly to install. Certainly more costly for the base install vs. more common oil or propane furnace. The operational costs appear to be lower, so the pure logic around valuing the system would be (increased installation cost)/(operational savings per year) = # years until payback.

It appears that a geothermal system is kind of like a pool or a finished basement when setting the resale value of a house. Some people might like it, some might dislike it, others may be neutral. It's hard to know upfront if the payback period will ever be realized by the homeowner in any measurable sense.

Given that geothermal systems seem to take longer than traditional fossil-fuel based furnaces to raise the temperature a setup amount, they appear to be most applicable to continuously occupied buildings (eg: not seasonal homes).

All the conversations about changing insulation values and methods are essentially moot, since they would apply to ANY heating system. Better insulation and management of heat loss is going to reduce the operational costs of EVERY kind of furnace.