We work with geothermal in Davison, MI, and we’re big proponents of homeowners choosing to have a geothermal heat pump installed for their year-round home comfort. Geothermal heat pumps work on the same principle as standard air-source heat pumps, which is that they use the circulation of refrigerant to move heat from one place to another. In hot weather, the heat pump pushes heat out of the house. In cold weather, it reverses direction and pushes heat into the house.
The difference between air-source heat pumps and geothermal (or “ground-source”) heat pumps is the medium they use for heat transfer outside of the house. The air-source heat pump draws or releases heat into the air, and the geothermal system uses the ground at least six feet below the frost line.
Many homeowners are concerned about whether a geothermal heat pump will do the job they want from it during the winter. Do they need to have a back-up heater to help the system supply enough heat?
Geothermal Systems Work Well in Extreme Cold
This is the first thing to know to answer this question, because there’s a common misunderstanding that geothermal heat pumps will suffer a drop in efficiency during freezing weather. The reason people often believe this is because standard heat pumps can lose efficiency in extreme cold. It’s easy to assume geothermal heat pumps will have the same problem.
But it’s the opposite case. One of the biggest benefits of using geothermal energy to heat a home is that a heat pump always has sufficient heat available to it in the ground. An air-source heat pumps struggles in below-freezing temperatures because it’s trying to extract heat from cold outdoor air. But a geothermal heat pump has access to stable underground temperatures, which range between 45° and 55°F no matter the weather. You can trust a geothermal system to keep up with your home heating needs and stay reliable even on the coldest night of winter.
Geothermal Heat Pumps Have Backups—But Not the Kind You Think
The idea of a “backup” heater for a heat pump comes from the popular hybrid or dual fuel heat pumps. These are heat pumps combined with a secondary heater, usually a propane furnace, that turns on to make up the heat deficit when the heat pump loses efficiency due to cold temperatures. They’re useful for homes that otherwise couldn’t enjoy the benefits of a heat pump.
Geothermal heat pumps do not need to be hybrids. There is no need for a secondary heater like a propane furnace to turn on and assist with heating—because the heat pump always has enough outside heat to use. Geothermal systems do come with backup heaters, but they only turn on it case the geothermal system fails entirely. A precaution, nothing more. If you take regular care of your geothermal heat pump, you shouldn’t need the backup to turn on at all.
To find out more details about switching to geothermal heating and cooling, talk to our specialists.