NET-ZERO SCHOOLS | FUTURE RESILIENCE against a changing climate. Other potential low- or no-cost measures include passive improvements to the building and its microclimate for example, tree planting to increase shade and changing user behaviours (flexible dress codes or school hours). These are the first steps in the cooling hierarchy further guidance is given in Annex 2F of the Output Specification.4 The CIBSE schools working group will continue building the evidence base to inform industry guidance for climate change adaptation. Its next steps include further research into the risks of extreme weather and the life-cycle costs and benefits of climate resilience for UK school buildings. CJ TWEAKING THE NIGHT-PURGE CONTROL STRATEGY Schools are a core market for contractor BAM, so a consistent understanding of the inuse performance of completed buildings is a real opportunity to identify efficiencies and improve the next generation of projects. Night purging is a core part of low carbon strategies to prevent summer overheating. North Somerset Enterprise and Technology College, in Weston-superMare, is a superblock with hybrid cross-ventilation in classrooms and a night-purge strategy through high-level secure vents in the atrium. Temperature monitoring was undertaken by BAM during the schools first summer as part of seasonal commissioning. Data confirmed that the night cooling was effective, reducing classroom temperatures across the building from 3am (under BMS control). However, the monitoring revealed that the heating was coming on at 6am to heat rooms to the 19C setpoint, thereby wasting energy and money, and undoing any free-cooling benefits. The case study highlights the value of seasonal commissioning to ensure good performance across the seasons, and shows the importance of integrating different systems in the controls strategy. All days monitored (4 weeks) TIM TAYLOR, JOE JACK WILLIAMS and PAULA MORGENSTERN are from CIBSE School Design Group References: 1 UK Climate Change Risk Assessment 2017 Evidence Report CJApr20TT2 2 Climate change: second national adaptation programme (2018-23), July 2018, Defra CJApr20TT3 3 UK Climate Projections (UKCP), CJApr20TT4 4 Output specification: generic design brief and technical annexes, June 2019, DfE, CJApr20TT5 3am night purge (MVHR-enabled, roof light open) Carpet plot Time of day Blue: gets colder 6am heating comes on to warm rooms beyond 19C setpoint Red: gets warmer One day from 00:00 to 24:00 hours >> Optimise control to avoid energy waste A carpet plot showing the time of day and change in temperatures over a four-week period for the school, as recorded by BAM First-floor room, SE-facing Second-floor room, NW-facing Ground-floor room, SE-facing EXPERT ADVICE & SUPPORT From the name you can trust GAS SAFETY Gas Proving, Detection & CO2 Monitoring Wide range of Gas Safety & Air Quality Monitoring Systems UK Manufactured 5 Year Warranty BIM Objects Available Specialist Gas Detection System design COMING SOON... 01925 281 230 E: W: @GasSafety_FF 42 April 2020 www.cibsejournal.com CIBSE Apr20 pp40-42 Supp Resilient net zero schools.indd 42 20/03/2020 16:28