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Home » UK survey reveals ventilation directly related to risk of virus spread

UK survey reveals ventilation directly related to risk of virus spread

A survey of 20 school classrooms carried out recently by National Air Quality Testing Services (NAQTS) has revealed very low air change rates that can increase the risk of virus transmission and spread. 

Douglas Booker, NAQTS chief executive, says “Our study showed that some classrooms had air change rates below 0.5 changes per hour and that even small increases in flow rates could significantly reduce the risk of infection. Raising airflows from zero to 100 cu m/hr cuts the risk by up to 60%.”

Booker said it was important to focus on what was “reasonably achievable”, particularly in an education setting where budgets are constrained, but that low cost adjustments to ventilation were a good investment. He added that above 100 cu m/hr there are gradually diminishing rates of return from increasing the flow.

Booker said, “This crisis is an opportunity to improve the indoor air quality performance of buildings for the long-term, but we need to focus on affordability. There is a lot of money going into shiny new academies, but that risks increasing inequality even further by leaving older school buildings behind. The important thing is having quality information and we are using the level of CO₂ to show whether the ventilation is working as intended.”

Booker also cautioned against what he called ‘over-sanitising’ of the indoor environments. He said: “Simply ramping up cleaning procedures could create unintended consequences that do not address the full range of infection risks. Don’t throw the baby out with the bathwater.”

Booker said the World Health Organisation’s (WHO) latest announcement and growing awareness of the risks posed by airborne pathogens inside buildings would spark greater demand for the specialist expertise of the building engineering sector.

The WHO’s statement that “evidence has emerged” that Covid-19 can spread through the air in enclosed spaces has been welcomed by the industry which has been making the same warning for quite some time.

The WHO’s technical lead for infection prevention and control, also noted that evidence emerging of airborne transmission of the coronavirus (and other viruses) in crowded, closed, poorly ventilated settings must be considered seriously. If a pandemic forces people to spend almost all of their time indoors, a change in perception and attitudes to indoor air quality is obvious.