Frederick Corson’s 5000 square foot home in Northern California’s wine country is much bigger than the average home, but it’s heated and cooled entirely by geoexchange.

A retired chemical executive, Corson knew the technology worked so when he moved to the hills of the Alexander Valley, he put a ground-source heat pump (aka geothermal heat pump) into his home.

Since the earth’s temperature is a constant 60 degrees if you go down 200 feet, he put a series of U-shaped tubes 200 to 300 feet beneath his backyard vineyard. A mix of water and alcohol or ethelyn glycol runs through the tubes from inside his basement to the tubes and back acting as the primary heat exchanger.

In this video, Corson shows us his equipment room and how his spacious home stays very cool even on the hot summer day (in the nineties) when we visited.