We have construction equipment! They just finished up with the previous job, and the equipment has been delivered to our property.

The geothermal system — WaterFurnace Series 7 — is installed in our house. There’s a pump mounted to the wall, but nothing is plumbed together because the loop field has not yet been installed. That’s what this equipment is for – they are going to dig a big hole in the yard (maybe 8 foot by 4 foot). A whole bunch of 3/4″ tubes will run into this hold & connect to a manifold. There’s another hole dug next to the house, and 1.5″ tube will go from the manifold to the exterior wall, through the exterior wall, through the pantry, and into the furnace room to attach to the pump.

The fluid that’s run through the loop field is run through the WaterFurnace unit, and heat is extracted into the refrigerant. And that’s what will heat our house. There are a lot of good non-technical write-ups of how geothermal heating works, but I found a decent somewhat technical write-up from a geothermal installer in Western PA.

This heat will be used to heat the house … and as long as the loop field temperature stays fairly reasonable (upper 30’s, I think), we should be able to sustain a comfortable temperature without engaging the heat strips. We’ve talked to quite a few people who use new-ish geothermal units that have only used the heat strips in extreme temperatures (it was -20 for a week a few years back) or when they increase the thermostat by more than two or three degrees. If you lower the house temperature to go away on holiday, don’t set the thermostat back to normal immediately upon returning home. Slowly increase the set-point by a degree or two every few hours a day before you plan to return – by slowly increasing the temperature, you’ll avoid using the heat strips.