In this episode Nathan's guests myth bust heat pumps. He is joined by Bean from the Ground Source Heat Pump Association and Heat Pump Federation; Robin who is also from the GSHPA and Bill, a heat pump specialist. All 3 guests are engineers with a vast amount of knowledge with heat pump technology.
Heat pumps are a recognised technology for helping the UK decarbonise heat and reach net zero. Unfortunately, there does seem to be some myths about what they can and can not do.
Here are the myths around heatpumps we discussed:
- Inverter driven compressors are more efficient than fixed speed compressors. Bill starts us off with this one. As you will hear, inverters are efficient but again it comes down to design. Different heat pump designs and applications may benefit from fixed speed compressors.
- Heat Pumps are maintenance free and free energy. Kind of two myths rolled into one.
- Heat Pumps need to run all the time. Robin starts this one off by discussing an energy savings trust study and Bill finishes with a German study on ground loops.
- A high temperature heat pump can just replace a boiler. Again, you will hear, the guests discuss design. Low temperature heating is becoming more realised in the industry along with hydraulic design. Bean alludes to the new qualification the CIPHE are producing regarding this and also talks about some of the problems we find with underfloor heating (UFH) installation work
- Heat Pumps only work in new builds. Bean discusses how as an installer he was installing heat pump systems into grade 1 and 2 listed buildings. The topic of hybrid heat pump systems is brought up. All guests and Nathan considered the fact that boilers are not needed as back up. In district heating systems it may make sense but we can design heatpump systems to not need boilers
- Heat pumps only work with underfloor heating Robin discusses how some heat pump installations have been cancelled because of a notion UFH was needed for heat emitters. A problem especially in the non domestic sector
- Fitting a larger ground loop fixes most problems with ground source heat pumps Again we hear the importance of hydronic design and understanding pressure drop
- You need a room thermostat in every room to comply with building regulations and for efficiency How do we control heat pumps and comfort. Listen to Nathan's guest talk about weather compensation and other forms of control
- Low Loss Headers should be used on all heat pumps Hydronic separation, flow rates and delta t is par for the course in this chapter
- All heat pumps are noisy Will heat pumps make frustrate our neighbours?