3. Air-source heat pumps
This air-source heat pump from Sanyo is unusual in
that it uses carbon dioxide as the refrigerant to make possible higher flow temperatures without losing efficiency.
Air-source heat pumps are widely considered to be less efficient than ground-source but are arguably more readily installed in existing buildings. Without the need for groundworks, they can be considered for a wider range of applications, including densely packed urban areas unsuitable for ground-source heat pumps. Will this adaptability outweigh the greater ‘bang for your buck’ offered by ground source?
Generally less costly to install than ground source models, they use the outside air as a heat source or heat sink to heat or cool an interior space.