Air quality monitoring and filtering

[quixoticgeek]

With winter fast approaching, out current approach in the office of having every window open for ventilation, is not going to be very viable. We know that air quality management is a great way of lowering the risk of infection in the office. I've suggested we get a number of HEPA filters to pull out aerosole droplets from the air. I've also suggested we get PM2.5, PM10, and CO2 monitors for the office so we have some data on how effective these measure are.

Has anyone else done this? Has anyone found useful guideline figures on how high the PM2.5 and CO2 should be allowed to reach before we panic?

J

[road-runner]

CO2 levels are shown at, for example, www.kane.co.uk. UK outdoor air is usually around 400ppm. 5,000ppm is a common maximum indoor workplace level maximum.

My experience is that I am used to around 300ppm (home office with an open window), probably because I live near mountains where the air is known to be good. At 600ppm (normal in a room where I am doing physical work) I can tell the difference, at 900 (sleeping alone with the window closed) I feel the room is a but muggy, at 1,200 overnight (two of us in the same room with the window closed) I wake up feeling groggy. Our CO2 meter's display goes from green to yellow at 1,000ppm and to red at 1,400ppm.

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As for PM2.5 and PM10, the government's web site says (here):
The Air Quality Standards Regulations 2010 require that concentrations of PM in the UK must not exceed:
An annual average of 40 µg/m3 for PM10;
A 24-hour average of 50 µg/m3 more than 35 times in a single year for PM10;
An annual average of 25 µg/m3 for PM2.5.