“A large measure of temperature control is provided by a combination of automatic bypass, speed differential between fans, night cooling and optional cooling modules,” he added.
“The common alternative, opening windows, offers no opportunity to recover heat from the outgoing air. Additionally, school staff tend to open windows in response to rising temperatures rather than ‘stuffiness’ caused by elevated CO2 levels. There are also issues of security, air pollution and noise ingress associated with opening windows,” he continued.
He also noted that traditional centralised ventilation systems are typically specified on the assumption that all of the spaces will be fully occupied all of the time. However, as occupancy of teaching spaces varies considerably through the course of the day and evening, this can waste energy through continuous ventilation of unoccupied or partially-occupied spaces.
“Decentralised units use high efficiency, EN308-compliant counter-flow aluminium heat exchangers that recover at least 84% (dry bulb) of the heat energy in outgoing air (91% at 80% relative humidity). An integral data logger constantly measures the performance of the unit. Further energy savings are achieved by the use of variable speed EC motor technology to minimise the energy consumed by the ventilation drives,” he concluded.