Geothermal Heat Pump Efficiency vs Air-Source

Today, more than ever, efficiency has become an enormous factor for consumers trying to choose a new heating and cooling system for their homes. It is well-known to consumers and installers alike that a geothermal heat pump is much more efficient at heating and cooling than air source heat pumps and other traditional heating and cooling methods. But just how much of a difference does geothermal heat pump efficiency really make?

Determining Geothermal Heat Pump Efficiency

The first step in understanding how much more efficient a geothermal heat pump system is than a traditional system is understanding the ways that efficiency is measured in the industry of heating and air conditioning. A heat pump has two most common measures of efficiency. The cooling part of a heat pump is measured in EER, which stands for Energy Efficiency Ratio, and the heating efficiency of a heat pump is measured in COP, which is Coefficient of Performance, the ratio of heat output to the amount of energy input of a heat pump.

Geothermal Heat Pump Efficiency Ratings

Air source heat pumps typically have EER ratings between 10 and 13. A DSZ16 has an EER of 12.5, and a DSZ18 has an EER of around 13. A single stage geothermal heat pump will usually have an EER rating around 17 or 18, along with 2 stage geothermal heat pumps on their full load. A 2 stage geothermal heat pump will have an EER rating of around 30 on its partial load. The COP of these systems follows the same trend. The COP of an air source heat pump will be around 4, while geothermal heat pump systems will have a COP of 5.

Geothermal heat pump systems are much more efficient than air source heat pumps due to the fact that they use the moderate ground temperature to heat and cool, while air source heat pumps use the extreme ambient temperatures of the air in summer and winter. This is why geothermal heat pumps have such incredible efficiency ratings.