Air Source Heating
Air and water source heat pumps use air or water respectively. They do not rely on a collection system and simply extract the heat from the source at the point of use.
Air source heat pumps can be fitted outside a house or in the roof space and generally perform better at slightly warmer air temperatures. These are more suited to smaller properties and are more efficient in applications where underfloor heating is or will be installed.
Photos courtesy of NIBE Energy Systems Limited