Modern Building Services

20 MODERN BUILDING SERVICES MAY 2023 FEATURE ELECTRICAL SERVICES Collaboration is key to unlocking energy efficient heating A recent study by Climate Watch estimates that the operation of commercial buildings is responsible for 6.6% of total global greenhouse gas emissions. And, according to the UK Green Building Council report, Delivering Net Zero: Key Considerations for Commercial Retrofits, 70% of the UK’s non-residential building stock was constructed before the year 2000. Meeting energy and carbon targets and achieving the UK’s 2050 net zero ambition means that the majority of the UK’s commercial buildings will have to undergo some form of retrofit over the next 25 years. Is it worth retrofitting an old building Older buildings are often seen as inefficient because they are less likely to bewell insulated or equipped with the latest technology. However, when you take into account the carbon generation associatedwith newdevelopment the pendulum swings the other way, and themost sustainable buildings are generally the ones that already exist. A new build project is only carbon neutral when the carbon generated in manufacturing, transporting and installing building materials has been accounted for. Many commercial newbuilds may never reach this point before the building is in need of redevelopment. The silver bullet has lost its shine The Government continues to champion heat pumps as the saviour of energy efficient heating, but according to a new National Infrastructure Commission report the installation of domestic heat pumps is falling well short of government targets. Around 55,000 heat pumps were installed in 2021. This is against a target of at least 600,000 per year by 2028. The fact that there are no targets for the commercial sector – at least as far as I am aware – tells a story in itself about the suitability of heat pumps for non-domestic buildings. In the right setting, there is no question that heat pumps offer a low energy consumption alternative to standard gas boiler systems. But not every setting is the right setting, and when a leading heat pump manufacturer is advising against their installation in older properties, it’s clear this isn’t a one size fits all approach. What are the challenges When it comes to performance and the practicalities of installation, the effectiveness of a heat pump can be compromised by several factors. Aside from a shortage of qualified installers, there are the challenges of maintaining heat when a building is not well insulated, reduced performance at low temperatures, and the size of radiator required to heat the space. This is the challenge I seemost often.To generate sufficient warmth to heat a space using a heat pump, a radiatormay need to be double, either in depth or length, the size it would be if installedwith a traditional boiler. A newbuild property can be designed to accommodate this, to a point. In a retrofit project, it is far more challenging. The availability of outside space is another consideration. Because heat pumps sit outside the property, space can be an issue for installing systems in urban areas, such as city centre retail premises. Taking the lead So, what’s the solution for commercial retrofit projects? The heating industry is under pressure to meet government targets, and the solution that is being widely championed is not ideal for many commercial buildings. Scott Conor , Technical Director at Trust Electric Heating, looks at sustainable, efficient heating solutions for commercial retrofit applications.