The efficiency of an air source heat pump is often referred to as its Coefficient of Performance (CoP) or as a Seasonal Performance Factor (SPF). The CoP is the performance of a heat pump at a stated air temperature and flow temperature, whereas the SPF reflects the performance of the air source heat pump over a year.
As air source heat pumps rely on the ambient air as the energy source, they are more efficient in warmer weather than cold, and likewise are more efficient at producing lower temperatures for heating.
A correctly sized air source heat pump for a well-insulated home will be around 300 – 400% efficient (SPF of 3 to 4), this means that for every 1kW of energy supplied to the air source heat pump, between 3 to 4kWh of energy is delivered.
As part of the system design Fervo will advise you what the SPF of your GSHP will be and will provide an estimate as to what it will cost to run.