Air source heat pumps are increasingly seen as an option for self-build projects, they are still relatively new additions to the heating system portfolio of options in the UK, although they have been available for many years – with models installed in the 1970s and 1980s in the USA still operating.
As with many things in life, here in the UK we were less willing to embrace new technologies than other countries. So here we are in 2015, and air to water air source heat pumps are now a serious mainstream heating option, with a wide range of models available and most major manufacturers of heating equipment recognising the requirement to have an air source heat pump range up their sleeves, even if they are support equipment for the products they are perhaps best known for.
The arrival of the domestic Renewable Heat Incentive (RHI) has undoubtedly seen the attraction of air source heat pumps and other renewable technologies grow virtually overnight. MCS (Microgeneration Certificate Scheme) approved equipment, sees the energy produced qualify for the domestic RHI – currently 7.42 pence per kilowatt hour of renewable heat produced. So selecting an air to water heat pump will see the owner of a domestic heat pump receiving payments quarterly for seven years, which is an attractive bonus.
The key benefit of an air to water heat pump is the energy efficiency that comes with the product. A typical, traditional wet heating system offers a Coefficient of Performance (COP) of around or slightly lower than 1.0. ASHPs provide users with a maximum COP of around 4.5. Put simply, for every 1 kW of power it takes to run the pump it delivers up to around 4.50kW of output – which is impressive by any standards.
Selecting the right sized unit is key to performance. You should ask for professional reports with as much information as is required providing end users with estimates of cost and energy savings from each model available. The selection programme will also include MCS sizing rules for air to water heat pumps with design criteria.