How Geothermal Heat Pumps Work

Geothermal heat pumps are a sustainable and efficient solution for heating and cooling buildings. They create comfortable environments by harnessing the Earth's natural energy. Unlike traditional HVAC systems, which rely on burning fossil fuels or consuming electricity generated from non-renewable sources, geothermal heat pumps use the stable temperature of the Earth's crust to provide consistent temperatures. But how do geothermal heat pumps work, what are the different types, and can they benefit homeowners and businesses? Let’s discuss. Principles of Geothermal Heat Pump Operation A geothermal heat pump system contains a network of underground pipes, known as a ground loop, which circulates a heat transfer fluid throughout the system. This fluid is usually a mixture of water and antifreeze, and the loop is buried beneath the earth's surface, where temperatures remain relatively constant throughout the year. In most places, ground temperatures range from 45° F to 75° F, depending on geographic location and depth. During the heating cycle, the heat transfer fluid in the ground loop absorbs heat from the earth and carries it to the heat pump unit located inside the building. The heat transfer fluid passes through a heat exchanger, transferring its thermal energy to a refrigerant circulating within the system. And as the refrigerant absorbs heat, it undergoes a phase change from liquid to gas, increasing in temperature and pressure. The hot, pressurized refrigerant gas then flows through a compressor, where its temperature and pressure are further increased. During the cooling cycle, the process is reversed to remove heat from indoor air. As the heat is absorbed by the Earth, the refrigerant condenses back into a liquid state and flows to the compressor to repeat the cycle. Different Geothermal Heat Pump System Types Geothermal heat pump systems can be classified into three main types:

1. Open Loop
2. Closed Loop
3. Direct Exchange