The findings show an improved average performance over Phase 1’s results for air source and ground source heat pumps of 33 per cent and 22 per cent respectively.
However, the HPA says it is very concerned that the results could be misunderstood to be representative of current practice, as none of the test sites are necessarily installed to current MCS standards.
Terry Bowen, president of the HPA, said: “The report is trying to demonstrate that systems have to be designed and installed correctly right from the start and that if they are badly designed and installed (as in the case of many installations monitored over Phase 1) performance efficiency will suffer seriously. However, improvements can likely be made in the performance efficiency via interventions and, hence, the original deficiencies due to design and installation are mitigated to a degree. However, the system will never be as good as doing it correctly in the first place.
“For this reason the fuel cost savings demonstrated are somewhat poorer than would reasonably be expected from current installations because they are based purely on the efficiency of the Field Trial results.
“EST , DECC and their partners have produced a thorough analysis of installations which have always been recognised to be far from ideal , and the findings demonstrate conclusively that heat pumps are now a key component of UK heating.”