The importance of a heat loss report for air source heat pumps

There seems to be a lot of information out there about air source het pumps.They have been working for 20 to 30 years in Scandinavia and they are still one of the most popular main souces of space heating and hot water, why is that?


There is only one way to do this with accuarcy. A full survey of the clients property, its construction, insulation levels this is a long process on site and can take up to an hour with complicated properties or very large properties. Room dimmensions need to be taken, all window measuements, wall construction, floor construction, loft insulation levels, distance from the house for the heat pump.

Heat Loss report:

Full heat loss calculation using the manufacturers software is very important, while the basic principle of heat pumps remain the same, they vary in their structure, buffer tank / no buffer, inverter/ no inverter, monobloc / split system, hybrid e.t.c .When all the relevant data is taken from a survey and input into the manufacturers software it leaves very little margin for error, as long as the software is programmed for the UK climate, and within that there are various locations in the UK to take into consideration, here in Cornwall temperatures in the dead of winter are very different from those in Scotland. The consumer must demand to see a heat loss report, this is a requirment now from MCS the accrediting body for the RHI, the sooner this is standard practice the better.


A proffessional installation is essential, make sure the installer has been on the manufacturers installation course for the chosen heat pump, all heat pumps are not the same and one of the biggest issues clients have with heat pumps is a lack of understanding when it comes to operating the heat pump. The installer should be clear on the installation and commissioning process if they have been on the training course for the heat pump they are installing, and should provide the certification for proof.

Sizing the Heat Pump:

The software should size the heat pump correctly, and take into consideration radiators or underfloor for the central heating. This should never be done by rule of thumb. Remember heat pumps are tested for their efficiency at +7 degrees so if the house has a heat loss report of 9 kW then a 9 kW heat pump is not going to be capable of heating the home efficiently under +7.

See more heat pump blogs for advice on Heat Pumps and their application.

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Harvest Cornwall Ltd, Unit 6 Darbari Building,
Prow Park,Newquay,TR7 2SX

01637 808244 / 01637 854997

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