What is the difference between air source and ground source heat pumps?

Heat pumps use a vapor-compression cycle to transfer thermal energy between a building and an external source. Air source heat pumps are the most common models, drawing heat from the outside air, while ground source models extract thermal energy from the ground. Both systems achieve high energy efficiency by moving heat rather than generating it directly through electrical resistance.

What we know

• Air source heat pumps are the most common models of heat pumps available. [2]
• Ground source heat pumps represent a different category of heat pump system alongside air source, water source, and exhaust air models. [2]
• Heat pumps can achieve around 150% to 600% efficiency for heating because they use electric power to transfer existing thermal energy rather than create it. [3]
• A vapor-compression heat pump uses a mechanical compressor to raise the pressure and temperature of a gaseous refrigerant to transfer heat. [2]

Where to go next

• how it workedHow does a vapor-compression cycle work?
• compared withWhy are heat pumps more efficient than gas boilers?
• what followedWhat role do heat pumps play in climate change mitigation?
• the bigger pictureHow does electric heating compare to heat pumps?
• how we knowHow is the efficiency of air conditioners and heat pumps rated?
• an unexpected connectionHow do refrigerators use the same cycle as home heating pumps?Refrigerators operate on the exact same reversed refrigeration cycle principles as home heating heat pumps, just directed at cooling an internal compartment instead of a building.

Sources

• [1]heat pump (Wikidata Q131313) · CC0 1.0
• [2]Heat pump · CC BY-SA 4.0
• [3]Electric heating · CC BY-SA 4.0
• [4]Seasonal energy efficiency ratio · CC BY-SA 4.0
• [5]Radiant heating and cooling · CC BY-SA 4.0