Geothermal is not only more efficient its actually viable in below freezing weather. Air source heat pumps outside coils will freeze up with ice once the temperature goes low enough causing them to stop functioning.
The ground temperature 30 feet down is basically stable year round and well above freezing just about anywhere on earth. This allows them to function even mid winter in cold climates while air source heat pumps much switch over to more conventional heating.
The ground temperature 30 feet down is basically stable year round and well above freezing just about anywhere on earth. This allows them to function even mid winter in cold climates while air source heat pumps much switch over to more conventional heating.