Geothermal in below zero temps

Just a quick  blog entry, before our very cold below zero weather sets in this weekend. Yes, your geothermal heating system is the best in the world. That is… it is the most efficient system you could have chosen for your home. But some geothermal owners confuse efficiency with capacity. Even though geothermal is very efficient, we still size these heating and cooling systems just like all the other systems.

What does this mean? When does my geothermal heat pump, my standard heat pump or my gas furnace no longer keep my home at the 72 degrees that I normally request?

The industry standard for Central Indiana (guidelines from the Air Conditioning Contractors of America) is to maintain 70 degrees when it is 2 degrees outside. We say, 2 degrees is the “design temperature.” So this means a properly sized heating system would be able to maintain a 68 degree temperature difference. But we normally plan for and size for colder weather. With a Precision Comfort heating system, you should be able to maintain 70 degrees even in temperatures below zero.

How far below zero?

Every home is different and other variables like wind and solar heat will influence this. As you know (look at the date of this blog entry) our forecast is for -15 degrees below zero with a 24 mph wind. If your home is exposed to the wind, you may not be able to maintain 70 degrees in your home at these conditions. As long as you are staying in the sixties during these extreme conditions, your system is likely working perfect, as designed.

Should you have purchased a larger system with more heat capacity? No. We size for 99.9% of all winter hours in Central Indiana. If we sized systems for the extreme (as the weatherman said today… “Barbaric Cold”) then it would be much too large in all the other normal hours.

Be patient and the weather will warm to normal.

Gary Holt

Since starting the company in 1998, Gary has helped build Precision Comfort Systems into a local and trusted HVAC leader for Hoosier families and homebuilders. Gary, a licensed HVAC contractor for over three decades, is also a certified trainer in heat loss, heat gain, and air duct design. With more than 42 years of experience designing, installing, and servicing geothermal systems, Gary is one of the region’s most knowledgeable resources in geothermal.

Updated: July 27, 2024

SHARE THIS BLOG: