Answer by Dale Blundell (Atkins)
There are many factors that might contribute to a heat pump not working satisfactorily, which might be due to poor design, installation, control or maintenance:
- The building fabric is poor, making it difficult for the low temperature heat to adequately warm the building.
- The controls are inadequate or not properly commissioned. Best efficiency is obtained when heating rooms for longer but at lower temperature.
- The settings are incorrectly adjusted for the different Summer and Winter conditions.
- The evaporator is fouled. This might be due to ice or biological growth.
- For GSHPs, ground conditions will vary around a site, and may be different to that in the test borehole.
It is hard to fault find or fine tune for best efficiency. Electrical and heat meters should be fitted to enable close monitoring of the system.