Geo heat pump: German technology, built in FL!
Our ranch has old-school eco in its bones: 14-inch thick walls, low to the ground build with some high, south-facing windows, and a protected location in the low point of what was at the time sprawling acreage. But it still sucks up a fair amount of propane and electricity, of which nearly 80% comes from coal in NM – a solar paradise with 300 sunny days/year!
And with deepening drought/declining water tables, water as well as energy conservation are top priorities. So our task now is to retrofit the place with some of the best water- and energy-saving solutions – from high-tech to no-tech.
Today, the second of three geothermal heating/cooling units will come online. For those unfamiliar with this ingenious renewable energy technology (which we were until recently – thanks to Bruce Nilles and Bonnie, Susan and Howard Cosgrove for pointing us in this direction), here’s how it works: a water solution circulates through tubes deep into the ground, where the constant temperature of the earth acts as a source of heat in the winter and a heat sink in the summer.
In our case, eight ground loops each go 200 feet below the surface. The water passing through will come back heated (or cooled) to the 55 ° constant of the earth here. A compressor – think fridge or a/c – will then use an evaporation-condensation process to turn that into real heat (or cold, when the pump is reversed). For you techno-geeks I’ve included a diagram.
The retrofit has not been without hurdles, like the huge electric upgrade we needed. Or what was thought to be an ice blockage in the loop that ultimately turned out to be a dead rat (not the classiest wildlife on the ranch, but we’ve got to take the good with the bad).
Also it is not cheap, but thanks to a big federal energy tax credit (gracias Obama) and a matching state credit, it is affordable. And once we install our 24 Albuquerque-made solar electric panels (among the last before production moved to China – we still need a real energy policy), the system will be near 0 carbon footprint and 0 energy cost.
Invasive ranch surgery: routing the ground loop to the house
Now we can feel good about staying warm…and maybe even push that thermostat above 64! Stay tuned as we continue to share what we learn as we green up this old place…
[Thanks to Apollo Pipeworks for the installation of our geothermal system: www.apollopipeworks.com]