‘Don’t rely solely on HEPA filters’

This is not me making this statement … this is Dr Mike Ryan of the World Health Organisation (WHO) in a recent interview taken from the Irish Independent, writes Michael Curran (right), CIBSE Ireland Chairman and Head of Building Services, Energy and Utilities at NUI Galway. Dr Ryan says classroom-proofing must be multi-faceted as a “silver bullet” approach can do more harm than good.

There has been a rush lately to install HEPA (high-efficiency particulate air) filters in all classrooms and offices
as they are seen as the “silver bullet” to assist in fighting COVID-19 … but are we sure? The context of Dr Ryan’s comments reflects my belief that we are rushing to supply HEPA filters which may deactivate or displace the measures currently in place. So far the widely-published and implemented Covid-19 mitigation strategies have predominantly focused on reducing close-range transmission using face coverings, physical distancing, respiratory etiquette, hand hygiene and ventilation. There is a place for HEPA filters but only in the correct context.

CIBSE Covid-19: Ventilation (Version 5, 16th July 2021) updated the guidance for ventilation in buildings based on
further studies and reports issued in collaboration with WHO, SAGE, REHVA, ASHRAE and other professional bodies. It was also the first time it issued guidance on “air cleaners” by publishing a separate document called Covid-19: Air cleaning technologies (Version 1, 16th July 2021). Note all these documents are free to download from the CIBSE Ireland website.

See PDF of full article at Don’t rely solely on HEPA filters for ventilation