EVENTS | TECHNICAL SYMPOSIUM ENGINEERING THE NEW NORMAL Striving for net zero while making buildings Covid-secure has been challenging academics and engineers since the virus first appeared. Last months CIBSE Technical Symposium was an opportunity to share experiences in two days of live sessions discussing 64 papers. Alex Smith, Liza Young and Phil Lattimore report T he impact of Covid-19 on the design of the built environment was the dominant theme at the 2021 CIBSE Technical Symposium. There were 64 papers on the theme Engineering the built environment for the new normal, and the keynote address on day one was given by Professor Cath Noakes, one of the worlds foremost experts in transmission of airborne infections. Noakes, who was made an OBE for services to the Covid-19 response, told the online audience that the built environment had a big part to play in the management of the virus and other respiratory diseases. She said engineers had the challenge of designing for health, not just comfort and energy efficiency. There are a raft of competing priorities, she said. We need to think holistically about how we capture these. Noakes added that the multiple routes of transmission made designing Covid-secure buildings very complex, with behavioural factors such as social interaction being as significant as environmental ones. Building design cant manage all the behavioural factors, such as mask wearing and personal hygiene, she said, but current ventilation standards need to be reassessed to help dilute the virus. Higher ventilation rates may need to be increased, said Noakes. We have settled on 8-10 L.s-1 per person, but this is for comfort and not managing a disease. I suspect the rate needs to be higher than it is now. The paper voted as making the most significant contribution to the art and science of building services engineering was the Impact of various ventilation strategies CFD was also used to analysis the impact of a living wall on indoor air quality in a reception area at the Spine building in Liverpool, designed by AHR. Software was used to track and analyse the distribution of VOC concentrations in key areas of the new HQ for the Royal College of Physicians with and without planting and living walls. Many papers aimed to understand how Covid-19 is transmitted. In a session on Delivering and evaluating air quality in buildings, SimScales Dr Naghman Khan advocated the use of CFDs to model indoor air quality (see below). He said it could quickly generate outputs useful for Covid-19 mitigation strategies, such as whole-room ventilation rates, fresh air and fresh air ratio, placement of air supply and exhaust grills, and the air velocities and air mixing in proximity to the occupants. In the same session, Brendon McManus, of Clean Air Technologies, CFD model from SimScale showing cold air entering a room from ceiling diffusers and spreading through the room Covid-19 by Ventives Tomasz Lipinski. With a significant and urgent need for adaptation of high-occupancy buildings to provide the inhabitants with a safe indoor environment, Lipinski outlined in his paper how this can be achieved through new, safer ventilation strategies. This targeted research and a practical investigation, delivered in collaboration with BSRIA, used new CFD analysis and a fully monitored office space to analyse the air patterns and contaminant flows within a room with various ventilation strategies implemented. The paper offered a practical comparison between the most prevalent ventilation strategies and their impact on the possible spread of pathogens. 22 August 2021 www.cibsejournal.com CIBSE Aug 21 pp22-25 Technical syposium.indd 22 23/07/2021 12:00