Getting Support

There are two types of air source heat pump – ‘air to air’ and ‘air to water’. The Grant Aerona uses an air to water system which utilises heat energy captured from the air in ‘wet’ heating system radiators or underfloor heating. The process uses the same vapour/compression cycle that extracts heat in a domestic fridge. A refrigerant with a low boiling point is exposed to external air temperatures in an evaporator. The liquid boils off to a gas and absorbs the latent heat energy of the air. This gas is then compressed increasing the heat content in the refrigerant, before passing through a heat exchanger where it condenses back to a liquid state while transferring the heat to the water of the heating system. The liquid refrigerant is then re-circulated through the evaporator and the cycle is repeated. The heat source used by Grant Aerona³ heat pumps is entirely renewable which helps reduce the amount of harmful greenhouse gases being released into the atmosphere and, in so doing, lowers the carbon footprint of the household.

Air source heat pumps must be correctly sized to ensure that it can provide the required amount of heat output at the design conditions – typically when the outside temperature is at -3°C. To do this an installer must first accurately determine the heat loss from the property and then, using this information, correctly select the required size of heat pump based on the design outside air temperature. Grant will also assist with sizing the ASHP and the Heatloss of the building. The heat loss from the property must be determined from a full room by room heat loss calculation for the property concerned and not from: The output of the previously used gas or oil fired boiler An estimated heat requirement based on the floor area or building volume The use of a simple heat loss calculator (e.g. Mears calculator) The Energy saving Trust ‘Whole House Boiler Sizing’ simplified calculation method The declared heat outputs for all ASHP’s are based on the average UK outside air temperature of 7°C. However, as mentioned above, a suitable ASHP has to be selected that will deliver the required heat output at the design outside air temperature (typically -3°C) when there is less heat energy in the air for the ASHP to draw from. At -3°C, the output of the ASHP will be reduced (typically to around 80% of the declared output). It is this lower heat output value that must be used when selecting the size of ASHP to be installed. The installer should ensure that any proposed ASHP system has been correctly sized and the unit selected in this way before proceeding with the installation.

Yes you can install Afinia radiators with both high and low temperature systems.

Underfloor heating is generally installed into new builds since new floors are being installed. Underfloor can be retrofitted into existing building if existing floorboards are being lifted or new floor compositions being installed.