SPONSORED ROUNDTABLE | DECARBONISING COOLING Additional solar shading is key to helping cool a building and we then look at the efficiency of the cooling kit Richard Cobb of safety regarding flammability already allows more sophisticated leak-detection systems, said DallOmbra, but he agreed that a central database would be very beneficial. Asked whether recycling refrigerant was an option, DallOmbra added: Reclaimed R-32 is currently not as big yet, because it is relatively new and theres less stock that can be re-used continually. But theres no doubt there will be a solution in about two years, with even lower GWP for the smaller residential systems. Punter argued that the issue isnt just about refrigerant leakage; the industry should ensure that buildings are performing as intended and are designed well from the start, she said. There has been a tripling of energy consumption used for space cooling since 1990, which is putting electricity grids under strain, especially during periods of extreme heat, such as the one experienced in Europe this summer. As a result, space cooling accounted for nearly 16% of the global building sectors electricity consumption in 2020 (about 1,885TWh)1. The panel agreed that, before calculating how much cooling buildings require, passive measures must be applied to minimise the energy used in cooling equipment. Cobb highlighted some typical passive measures he employs to help cool existing commercial buildings. Taking a fabric-first approach is the first step, he said. A buildings thermal mass within the fabric is then considered, as well as finding ways to upgrade its U-value. Additional solar shading is key to helping cool a building and we then look at the efficiency of the cooling kit, said Cobb. If its near the end of life, we look at refurbishing it or installing a new system. If the buildings faade is degraded so much that it needs to be replaced, we would remove the skin, keep the structure if we can, and reclad the building with modern thermal. Historic buildings require a different approach given their faades architectural significance. Cobb added that refurbishing cooling plant is preferable to replacing it. By keeping some of the components he wants to limit the amount of total carbon spent. I always look at carbon in terms of currency, said Cobb. The industry needs to say, this is what were going to do to this building and it will cost you this much carbon for its whole life. If we did this, we could reduce carbon by simply changing the materials. Stephen MacLoughlin, regional director, and net zero carbon lead at Faith + Gould, agreed that a fabric-first approach and external shading are powerful passive measures. He suggested that the UK could learn Its so strange that theres so little information about refrigerant leakage, yet its a controlled substance Hugh Dugdale from architecture in hotter countries, which employ straightforward solutions to address solar gain. MacLoughlin has concerns, though, about the commercial sector and the landlord/tenant situation. Providing comfortable internal conditions for employees when temperatures rise, while also addressing energy efficiencies, will present challenges. Punter highlighted new guidance by the British Council for Offices that could have an impact on this issue, as it includes relaxing occupant densities in a post-pandemic world. She also mentioned her work with listed buildings Making it clear to clients which refrigerants are most appropriate for their system is very important - Bianca Laura Latini 40 October 2022 www.cibsejournal.com CIBSE Oct 22 pp38-40, 42 Roundtable.indd 40 26/09/2022 16:07