Energy Saving Trust – Heat pump field trials Phase 2
I’ve had a read through this and the main points seem to be that improved installer standards are having the desired effect of increasing performance and that monitoring enables diagnosis of faults and improvements to be made. What it also highlights though is that design and commissioning are still key to achieving high performance. The systems with the highest monitored performances (SPFH2 3.9 and 3.94) are both feeding under floor heating at around 30DegC. This shows how important the distribution system is in the whole scheme of things. There is clearly going to be a big difference if the heating is designed run at 30DegC than if it is designed to run at 50DegC.
The technical document describes the different measures of seasonal performance factors SPFH1 –SPFH4. Basically 1 is just includes the heat output and the compressor energy, 2 also includes the source pump/fan energy, 3 then includes the auxiliary heat and 4 includes the heating system circulation pump/fan energy as well. SPFH4 is the only true measure of a heating systems performance as you can’t ignore the significance of all these additional energy uses. Improvements described in the ‘interventions’ section include adjusting how the auxiliary heat was controlled and also replacing fixed speed pumps with variable speed ones both had dramatic effects on SPFH4. Again this highlights the need for good design in the first place.
Some of the ‘intervention’ work involved alterations in line with current updated installation standards and some of these (not all) resulted in improvements to performance which is good news for the industry and for end users as it signifies that the improved standards are having the desired effect which will in turn increase consumer confidence.
End user feedback has been very positive with the main problem for them being lack of information. The manufacturers and installers need to address this one together and with the modern age of communication this should be easy. Maybe a public forum on the heat pump associations website (@GSHPAssociation ??).
All in all pretty good news