SPONSORED ROUNDTABLE | HEATING TAKING THE HEAT OUT OF DECARBONISATION Eight industry experts came together to discuss the challenges of decarbonising heating in CIBSE Journals latest roundtable. Amanda Birch sums up the main points of debate O ur recent roundtable, on ensuring a balanced and responsible approach to decarbonisation of heating, generated a lively discussion on the challenges of targeting net zero carbon while providing comfortable, cost-efficient buildings. Factors such as insufficient space for air source heat pumps (ASHPs), oversizing of equipment, noise, vibration, the importance of controls, and inadequate legislation were highlighted as key issues. The event, sponsored by Baxi and held in London, explored ways of optimising heating systems. The participants began by describing their decarbonisation projects and challenges. Mathew Stark, a senior mechanical THE PANEL Richard Brimeld, associate at Ridge and Partners Jason Donoghue, head of marketing at Baxi Louis Kimber, mechanical engineering technician at AtkinsRalis Ryan Kirkwood, engineering solutions manager at Baxi Jeremy Owen, principal mechanical engineer at SVM Building Services Design Daniel Skidmore, director of building engineering at Aecom Mathew Stark, senior mechanical engineer at Hoare Lea Simon Wyatt, partner at Cundall and chair of CIBSE Knowledge Generation Panel engineer at Hoare Lea, cited a current refurbishment scheme. We wanted to remove the gas boilers and use an all-electric system with ASHPs, but planning restrictions wouldnt allow anything too tall on the roof, he said. The cooling system uses air cool condensers on the roof and chillers in the basement. Instead, we changed it from a constant air volume to a variable air volume system so we could at least make the system more efficient and decarbonise in that way. Simon Wyatt, partner at Cundall and chair of the CIBSE Knowledge Generation Panel, said many building owners are struggling with the best way to decarbonise existing buildings. They question whether they should do minor works now or carry out a deep retrofit over a phased period. Wyatt is involved in decarbonising many existing buildings. His dilemma is whether to try to keep a high-temperature heating system or upgrade the buildings fabric. The cost of electrification and heat pumps is expensive, but its a drop in the ocean compared with the cost of upgrading the fabric, he said. If you want to hit those energy intensity targets, this is a real issue and theres no coherent solution. Richard Brimfield, associate at Ridge and Partners, and founding committee member of the CIBSE HVAC Group, argued that some of the obvious challenges are finding external space for heat pumps and boreholes, identifying the heat requirement for existing buildings, and 24 December 2023 www.cibsejournal.com CIBSE Dec 23 pp24-27 BAXI Roundtable 2.indd 24 24/11/2023 17:48