How Does a Geothermal Heat Pump Work?
If you’re considering a geothermal heat pump for home heating and cooling, here are the basics you should know about how these systems work – and why they are so efficient.
You may have seen commercials about geothermal heat pumps, and wondered what the big deal is. Many people choose a geothermal heat pump because they are said to provide quieter heat and air to your home and at a fraction of the cost of using a conventional heating and air conditioning model. Here are the basics about geothermal systems and how they work:
What Is Geothermal Energy?
Geothermal energy basically just means energy from the earth. “Geo” means earth and “therm” means heat. Even in places that constantly see subzero temperatures, there is heat in the air and more importantly, below the surface of the earth.
Harnessing this heat is what geothermal energy technology is all about. It uses the natural heat of the planet to heat our homes and also to turn that potential energy into electricity to heat larger buildings and areas.
Bringing the Earth’s Heat Home to You
Traditional heating and cooling systems use a condenser (outside unit) to pull in air from outside and heat or cool your home depending on the time of year and your needs. A refrigerant carries the heat that is circulated throughout your home. You may know that your heat or air is kicking in because you can hear the unit outside engage when a set temperature is reached. They can be noisy but they are usually located outside, which helps.
Now let’s look at the geothermal heat pump. Instead of pulling heat from the surrounding air, it depends on the heat from the earth to provide you with what you need. A series of coiled pipes called a “loop” create a closed system underneath the earth. Even at a few feet below the surface, the temperature is usually fairly constant, about 50 to 60 degrees Fahrenheit.
These pipes are buried below ground either horizontally, submerged in a nearby body of water, or vertically deeper into the earth. Water or other environmentally-friendly liquid is circulated within the pipes. The pipes carry the heat from the earth to your home where it is released through the ducts via an electric compressor and a heat exchanger that heats the air slightly to keep your home at the desired temperature.
When the weather is warm, the cooler earth temperatures help bring cool air into your home, which then is sent through the vents to keep your home cool and comfortable. Geothermal heat pumps typically run more quietly and contstantly, as they have variable speeds which adjust automatically to keep your home in your desired temperature range. While your geothermal unit will be located inside your home (typically in a basement or furnace room), it is usually much quieter than a traditional gas or oil furnace.
Geothermal heat pumps can be a great source of energy savings, and can help lower your energy bills – sometimes substantially. (To learn more about our own experience with installing a geothermal system, check out this post: http://www.newholisticliving.com/1/post/2015/10/homesteading-update-geothermal-install-complete.html)