Modern Building Services

MODERN BUILDING SERVICES MARCH 2021 15 FEATURE HEATING So why aren’t building companies already making the switch? Cities across the UK are continuing to grow, but limitations in urban areas have often posed challenges for heat pump retrofit; specifically, around strict limits on noise and finding suitable space. However, heat pump technology is diverse and versatile, and with appropriate design, installation and operation, heat pumps are technically viable across all London building types. For example, modern air source heat pumps are capable of noise levels well below those required for Permitted Development in dwellings. In addition, fully internal air source heat pumps can remove the need for an outdoor fan unit where external space is not available, and lastly, for densely populated areas, large heat pumps can be used in heat networks expanded to incorporate existing buildings. Another factor that has prevented companies from investing in heat pump technology is the familiarity and reliance on traditional gas boilers, and, quite often, a lack of knowledge around the benefits that heat pumps bring. Heat pumps can be applied to most building types, but are not a like-for-like replacement for gas boilers and electric heating systems, so careful and detailed system design is required to ensure they will work efficiently and effectively. However, if this is undertaken, most buildings can benefit. Finally, the primary barrier to heat pump retrofit is often the high up-front costs of the technology. Yet this is an unhelpful and legacy perception - many building types have a compelling financial case for heat pump investment when considering the overall lifetime cost. For example, office buildings that currently use electric chillers for cooling can benefit from passive cooling via reversible heat pump systems to achieve large fuel bill savings. Ideal for the shift to mixed use There is also a compelling use case for heat pumps in mixed use buildings – which is a burgeoning space in the UK built environment. Buildings which combine residential homes and commercial businesses have a wide variety of heating and cooling requirements within the same structure. To satisfy these needs without compromising on sustainability and the green imperative would have been challenging, before the advent of commercial heat pumps. Traditionally, this is where gas boilers, combined heat and power systems or electric water heating would have come in. Now, high temperature heat pumps – like the 40kW Ecodan QAHV – can deliver hot water up to 90 O C, helping businesses increase the efficiency of hot water production while slashing their carbon footprint. When paired with energy loops, the heat used from, say, cooling a public gym could provide hot water and heating for homes in other parts of the building. So how can more buildings benefit from this? Firstly, it’s important to underline how technological developments in this space are happening all the time. For example, we are already seeing many examples of innovations across the industry around products that offer sound levels that are three times quieter than previous models, virtually eliminating the challenges around planning restrictions. It’s also vital that the industry continues its education work around the viability of heat pumps as a part of this green heating shift, and that they are well understood and recognised by builders, planners and contractors alike. As well as energy efficiency, heat pumps can be applied to nearly any application – sometimes requiring only small adjustments – and there are long-term cost savings associated with installing a more efficient form of heating. Lastly, the higher up-front costs of the technology relative to alternatives such as gas boilers or standard electric systems, needs to continue to be offset by policy, strategies and higher levels of subsidy to make the financial case for heat pumps more compelling. While it is important to realise that there are many other aspects that contribute to the energy efficiency of buildings, if we are to meet the UK’s ambitions to be net zero by 2050, thought leaders, industry, government and local authorities need to come together to ensure the heat pump supply chain is innovative, efficient and readily supported across the UK.