Optimise Energy Efficiency in School Ventilation

Published by Angela May for Passivent Ltd in Education and also in Local Government

One of the largest single education PPP projects has turned to Passivent to help achieve optimum energy efficiency and best practice….. Passivent has worked with Morgan Ashurst on a £130m PPP for East Dunbartonshire Council, building six new secondary schools. Under the scheme, schools have to achieve at least a ‘very good’ BREEAM rating, which Passivent natural ventilation is proven in practice to help achieve. Project architect Aedas and Archial has designed each of the schools to be effectively, naturally ventilated using 50 Passivent Airstract Terminals across the six schools, in line with the design brief of which a key element was ‘the successful integration of natural light and ventilation’. The largest of the new buildings, Bishopbriggs Academy for 1200 pupils, features 12 Airstracts, whilst the smallest 650-roll Turnbull High has five. The Passivent Airstract terminals utilise the Passive Stack principle, harnessing convection where warm air rises, and the venturi effect, wind passing across a terminal causing suction, to maintain ventilation flow rates and carbon dioxide levels in accordance with Building Bulletin 101-Ventilation for School Buildings. They use electricity only to attenuate the motorised ventilation louvres to adjust the extract flow depending on internal air quality. The system ensures a controlled flow of ‘used’ air out of the building, with fresh replacement air coming into and through the building through strategically placed vents above windows and doors, and being extracted through the Airstract terminals tactically positioned on the roof above stairwells. As the system functions constantly, 24/7, it also provides ‘free’ night cooling, allowing daytime heat build-up to be dissipated, and ensuring a fresh internal environment when pupils and staff arrive the following day. In addition, Passivent natural ventilation systems reduce energy consumption over air conditioned buildings by up to 50%, yield 15% savings on capital costs and 75% savings on maintenance costs, and eliminate the need for a separate plant room. Passivent is a founder member of the NatVent EC-EU-funded project co-ordinated by the Building Research Establishment to develop practical natural ventilation solutions for the commercial sector, and is developing “smart” solutions to promote adoption of natural ventilation. The company has contributed to the BISRIA guide BG2/2005 Wind Driven Natural Ventilation Systems, as well as being a member of the DfES steering committee on ventilation guidance for schools, Building Bulletin 101