Modern Building Services

14 MODERN BUILDING SERVICES MAY 2021 HEATING FEATURE HEATING W ith the upcoming changes to building regulations as part of the Future Homes Standard, there is no doubt that heat pumps are set to play a significant role in the journey towards decarbonising heat in our homes. Homes – both new and existing – account for 20% of greenhouse gas emissions in the UK1. To reduce the carbon footprint of our homes, the UK Government has committed to introducing a Future Homes Standard by 2025, which includes plans to phase out fossil-fuel heating from all new homes in favour of heat pumps and other low carbon technologies2. By then, we will reach the next milestone in the phase-down of F-gases as dictated in the F-gas regulations. Although the two pieces of legislations are separate, their combination has opened up a unique opportunity for Vaillant – which is more well-known as a boiler manufacturer – to introduce a different refrigerant to the heat pump market to deliver comfort in people’s homes whilst minimising their carbon footprint. Phase-down of refrigerants While it is commonly understood that heat pumps are a green solution, there are differing environmental impacts and operating efficiencies of the various refrigerants in use within heat pumps on the market today. Historically, the most commonly used heat pump refrigerant was R410A, but with a GWP (Global Warming Potential) of 2088, it is currently being phased out of the market under the F-gas regulation. As a result, some manufacturers are now turning to R32 for their heat pumps. However, this substance has a GWP of 675. So, every tonne of R32 released into the atmosphere has the same greenhouse gas effect as the equivalent of 675 tonnes of CO2. As a manufacturer of heating rather than cooling appliances, we are able to go down a different route - using R290. A better alternative R290 is the technical name for the natural refrigerant also known as propane. It is already commonly used in many parts of our daily life, such as in refrigerators, air conditioning or even hairspray. It has a GWP of 3 – 225 times lower than R32, and 696 times less than R410a. Every tonne of R290 used is equivalent to only 3 tonnes of carbon emissions from CO2, resulting in a much lower carbon footprint. By the time the Future Home Standard comes into effect, the total amount of emissions equivalent to CO2 allowed will only be 31% compared to the baseline, with a further reduction to 21% in 2030. So, whilst R32 is undoubtedly a greener solution than R410A, the likely level of growth for the heat pump market means that it will be unacceptable under F-gas standards with some predictions stating as early as 2024-26. By using R290 instead of R32 in one of our heat pumps, not only is the it protected from the reduced availability of HFC refrigerants in the years to come, but it will also make a bigger contribution towards the country’s target to reach net-zero by 2050. What’s more, heat pumps which utilise natural refrigerants such as R290 are able to use less volume per kW, allowing them to achieve the same, or greater results than counterparts, more efficiently. More hot water The other key reason why R290 is a better choice is its ability to deliver more hot water to the hot water cylinder and at point of use. Most heat pumps with R32 as the refrigerant, can only handle flow temperatures of up to 65oC in a hot water system. Thismeans that a back-up heater (direct electric immersion heater) is required in the hot water cylinder to store the hot water above 60oC – the point at which legionella bacteria is killed off. As traditional refrigerants used for heat pump technology are being phased out, Steve Keeton , Director of External Affairs and Future Portfolio at Vaillant, explains how the company has developed an offer to a long-term solution. The long game