How Do Geothermal Heat Pumps Work?

Every year tens of thousands of Americans make the switch from traditional heating and cooling systems to energy-efficient geothermal heat pumps. In doing so they decrease their overall energy consumption, reduce their carbon footprint, maintain their air comfort standards, and, best of all, start saving money. In fact, most of them will save enough money on their monthly electric bill to pay back the installation cost of the geothermal heat pump in five to ten years. That may make you ask the question: how do geothermal heat pumps work?

A basic heat pump uses the principles of refrigeration to heat or cool a home. It is a very simple system. To cool, an evaporator coil absorbs heat from the interior of the home, pushes it through a compressor, and then releases it through a condenser coil. A traditional air conditioner works in a similar way. The difference between a heat pump and an air conditioner is that a heat pump is fitted with a reversing valve that allows it to switch the cycle around to provide heating instead of cooling. This means a single unit can do what previously required separate systems.

Most heat pumps, at least historically, have been air-source heat pumps. They used the air as a source and a heat sink. The difference between an air-source heat pump and a geothermal heat pump is that source. A geothermal heat pump does not use the air outside the house, but rather the ground or groundwater beneath it. Air temperature can fluctuate rapidly which makes it an inefficient source. By contrast, the temperature below the earth’s surface rarely fluctuates much at all even during the hottest or coldest weather. Thus, a geothermal heat pump has a constant stable source and can by that means achieve a much more effective level of energy efficiency.

To sum up, a geothermal heat pump draws the heat it needs from the ground to warm a home in winter and puts heat it does not need back to cool a home in summer. The best part is that it does so a lot more efficiently than traditional systems. That means you get to save money month after month after month.