Heat pumps

Overall score breakdown

Our score is comprised of:

Heating efficiency (70%)

Low temperature performance (20%) – where manufacturers fail to provide H2 ratings, the overall score is calculated with an assumed low temperature score of 50.

Indoor noise (5%)

Outdoor noise (5%)

About our assessment

We don’t test heat pumps. With more than 200 models available, there are simply too many to tackle. Instead, we compare and analyse data provided from manufacturers. This data comes from accredited laboratories.

Smaller heat pumps are more efficient than bigger ones. Our scores take this into account, so a model that scores highly for heating efficiency will be more efficient than average for a model of its size. A score of 70 indicates the average result for a model of that heating capacity (kW). The same applies for noise scores, so a large model scoring 70 for indoor noise will be louder than a small model that also scored 70 – check the dBA figures to see how models of different sizes compare.

Our low temperature performance score is based on the difference between the standard kW heating capacity (measured at 7°C) and output at 2°C (the H2 rating), the prime temperature for frost formation. Some brands don’t provide this information to us. If you live somewhere prone to winter frosts, look for a model with an H2 rating.