Heat pump suppliers are being urged to consider balancing an expected surge of installations in 2021 with long-term environmental targets concerning the global warming potential (GWP) of refrigerants used in the technology.
Following the announcement from the Heat Pump Association that 67,000 heat pump installations are expected in the UK this year, Vert Technologies is concerned that meeting this surge in demand will mean growing numbers of installations using high global warming potential (GWP) refrigerant working fluid.
Specifically, Nicol Low, COO at Vert Technologies, is highlighting the importance of moving away from using high GWP refrigerants as soon as possible, which contribute toward greenhouse gas emissions.
He says, “The fact that demand for electrically driven heat pumps is increasing against the gas-burning competition is clearly good news for the environment, but attention should be paid to where there is potential for further pollution. The high GWP potential of refrigerants used in these installations is often overlooked.
“The country is currently phasing out hydrofluorocarbons (HFC) used as refrigerants, such as R404A, R410A and R134A, as part of a larger effort to reduce HFC use by 79% by 2030. This is something heat pump manufacturers need to bring into greater focus if they are to futureproof their installations, as this phase-out will have long-term ramifications when it comes to ongoing performance.”
The removal of these pollutive HFCs from circulation in favour of natural, low-GWP refrigerants presents new challenges for the traditional compressor models used in heat pumps. Specifically, while better for the environment, these more sustainable alternatives require high pressure ratios and absolute pressures in order to achieve good performance.
Technologies such as Vert’s conical rotary compressor (CRC), could offer a solution. A scalable and inherently quiet technology, Vert compressors are able to achieve the high-pressure ratios and absolute pressures needed to get the best from natural refrigerants such as CO2 and ammonia.
“Continuing with long-standing solutions such as scroll, screw and reciprocating compressors could potentially leave heat pump manufacturers between a rock and a hard place, needing to compromise on either sustainability or performance,” explains Nicol. “By contrast, the adaptable rotor geometry and optimised pressure ratios of the CRC can be tailored for use with low GWP media, creating performant heat pumps without incurring significant extra OpEx.”
Great article. Yes, cost determines viability and can be the single most important factor in the failure of heat pump rollouts. Finally, technology has to be made affordable for customers.
One the other issues relating to retrofitting air to water heat pumps to existing dwellings is the flow temperatures from heat pumps being in the sub 60 degC level.
I have had two surveys carried out by potential suppliers. Both have advised that most of the existing radiators would need to be changed to create internal temperatures around 21degC. . This aspect doubled the cost of the heat pump project.
So it seems retrofit projects are unlikely to progress.
However CO2 refrigerant-based heat pumps can produce flow temperatures above 68 DegC.. What would be the sticking points for using these heat pumps??
When the heat pump is operating in the cooling mode, the refrigerant that flows through the indoor coil is a low temperature liquid. As the blower passes air from the conditioned space through the coil, the air, being warmer than the refrigerant, transfers heat to the refrigerant, thereby cooling the air.
The removal of these pollutive HFCs from circulation in favor of natural, low-GWP refrigerants presents new challenges for the traditional compressor models used in heat pumps.
The fact that demand for electrically driven heat pumps is increasing against the gas-burning competition is clearly good news for the environment, but attention should be paid to where there is potential for further pollution. The high GWP potential of refrigerants used in these installations is often overlooked.