Short answer: An air source heat pump moves heat from outside air into the home using refrigerant and a compressor, then delivers it through a heating system designed for lower, steadier flow temperatures.
An air source heat pump takes low-grade heat from outside air and uses refrigerant, a compressor and a heat exchanger to move that heat into the home.
The main homeowner difference is that the system normally runs at lower flow temperatures for longer periods, so the design has to match the rooms, radiators and controls.
A good consultation checks whether the whole system can deliver steady comfort rather than simply swapping the outdoor equipment.
Ready to check your own home? Start with a design consultation so the next step is based on the property,
not a generic online assumption.