There is a rush on CO2 meters, now it is clear that good ventilation of the classroom can help in the fight against covid-19.

Keep your distance, wash your hands, put on a mouth mask. We knew that one. But at the start of this special school year, another advice is given: ventilate the classroom. Covid-19 puts the need for ventilation on edge', says Marianne Stranger, expert in indoor air quality at VITO.

Children in a classroom all breathe air, which contains tiny droplets that float around for a long time. They can also spread the virus if there are infected children in the group. In order to keep the concentration of these particles as low as possible, it is crucial to freshen the air.

There are two ways of doing this. New schools have a mechanical ventilation system. 'But because it sometimes makes noise or creates draught, it is often switched off. Don't do that, because in such a well-insulated new building the bad air will accumulate. Rather call a maintenance technician to repair the system.'

Most schools have to ventilate manually. Read: open the window. That sounds simpler than it is. Because how many windows do you open and for how long? The initial tip of a quarter of an hour three times a day is not enough,' Stranger emphasises. Because one class is bigger than another, or has more pupils. Ideally, fresh air should be constantly supplied, for example through tilt windows. On top of that, the windows should certainly be open during every break and even after school hours. Even in winter, yes. The children and teachers will lose a bit of comfort when it's very cold, but healthy air now weighs more heavily.'

A good indicator of the quality of the classroom air is the CO2 level. We breathe out this gas and it is actually odourless and not harmful. But if too much of it hangs around in the classroom, those present will become sleepy and perform less well. Moreover, CO2 is linked to the presence of other pollutants. In other words, if you measure CO2, you get a good indication of how healthy the air is.

‘Ideally, fresh air is constantly being supplied, for example along tilted windows.’ - Marianne Stranger, VITO

There is a rush on CO2 meters nowadays. Even Prince Laurent showed himself to be a fan. There are good and not so good ones on the market', says Stranger. The important thing is to be able to interpret the measurement results and to take the right actions. That's why VITO works with the Care & Health Agency and the Education and Environment Departments on guidelines, instruments and advice.

Source: De Standaard