Air source heat pumps work very well with radiator circuits or combinations of radiators and underfloor heating. The primary flow temperature should be set at 50°C, to supply the radiators, whereas the underfloor circuits will have a “blending valve” to decrease this temperature. However, if using radiators, on a heat pump circuit, these will require re-sizing to comply with the lower temperatures of the pump. The radiators will require a correction factor of 2.5 to be calculated which increases their sizes by approximately 30%.
Homeowners and installers are encouraged to contact a member of the Grant UK Design Team for further information about correctly designing and sizing a heat pump system.