As school absences soar in England because of covid-19 – and classroom mask-wearing guidelines are lifted – many teachers aren’t sure how best to improve ventilation amid winter temperatures
26 January 2022
More than 350,000 carbon dioxide monitors have been distributed to schools in England by the UK government since September 2021. But poor communication on how to use the monitors to help curb transmission of the coronavirus is hampering their use and leading to pupils struggling in cold rooms unnecessarily.
About 1 million pupils in England were absent from school on 20 January, as were about 9 per cent of teachers. So far, under-11s in England remain almost entirely unvaccinated, making mitigation measures like ventilation all the more necessary – especially now that mask wearing is no longer required in classrooms.
That is where CO2 monitors can help. These give an indication of how well ventilated a room is, because when people breathe in and out in poorly ventilated spaces, the gas builds up over time. Rooms with high readings are likely to have inadequate ventilation for the number of people in the room and a higher risk of covid-19 transmission.
But CO2 monitors are only useful if well deployed. Data provided by TeacherTapp – a daily survey of teachers in England – to New Scientist suggests that teachers have received mixed messages on how best to use the devices and maximise classroom ventilation in the cold weather.
About 16 per cent of respondents said on 20 January that they had been given no guidance on the matter. Some 34 per cent of the 7175 respondents said they had been told to open all their windows as wide as they could and 18 per cent said they had been told to open their windows just a little.
Shivering in classrooms
This confusion has left many struggling in the January weather. A Year 3 teacher in Essex told New Scientist that her pupils have been shivering when she has opened the windows – even with coats on.
“The cold days have been very cold,” says a primary school teacher in Northumberland. He says he hasn’t been given any advice on what figures to be looking out for on the monitors.
CO2 monitors often work on a traffic light system. A green light indicates that the room has less than 800 parts per million (ppm) of CO2 in the atmosphere and so is well ventilated. And a room is considered to be poorly ventilated when a red light goes off indicating a reading over 1500 ppm.
Guidance from the UK Health and Safety Executive for ventilating buildings generally suggests that windows and doors should be opened when a CO2 monitor hits red. The UK Health Security Agency gives more nuanced notes and suggests that in cold weather, only top-level windows should be opened. But just 8 per cent of TeacherTapp respondents said they had been given this advice.
A Department for Education blog also suggests that classroom windows don’t have be opened very wide in winter. Only the general guidance issued by the Chartered Institution of Building Services Engineers (CIBSE) accurately echoes advice given by Shaun Fitzgerald at the University of Cambridge. “You want to crack open the high-level windows just a small amount,” says Fitzgerald, who co-founded a ventilation company based on his research. “That’s how you provide adequate levels of fresh air in space while making sure the room is not too cold,” he says.
Just 3 per cent of teachers said they had been given this advice, according to the TeacherTapp poll.
“If there are plenty of teachers who don’t know the best way to ventilate their classrooms, this is the time we should be telling them because we’re in the depth of winter,” says Fitzgerald.
Coping with the cold
Catherine Noakes at the University of Leeds, UK, who specialises in ventilation and airborne infections, says that when it is cold, windows should be opened intermittently, such as for 10 minutes every hour. Additionally, she says teachers should rearrange furniture so that children aren’t sitting close to windows.
“You can also open doors and windows more widely during break times to refresh the air in the room,” she says.
A major issue that schools have faced is that many windows, especially those high up, have been painted shut during refurbishments. Fitzgerald says fixing these should be prioritised.
Fitzgerald also says a red reading on a CO2 monitor isn’t necessarily bad. “Our modelling suggests 1500ppm is adequate in terms of daily averages,” he says. What this means is that, providing enough action is taken to prevent levels from climbing higher, there is no need to panic if a monitor is giving a red reading.
For classrooms without windows or ones that cannot be ventilated at all, the UK government has ordered 8000 air purifiers to help remove coronavirus particles from the air, according to a spokesperson for the Department for Education.
“Schools across the country have reopened and staff are working tirelessly to ensure settings can stay open for face-to-face learning,” they said. “Together with mass testing, bringing in supply staff and the hard work of schools and teachers, we are confident that our measures will maximise classroom time for students.”
The devolved governments of Northern Ireland, Scotland and Wales have also distributed similar monitors to schools.
More on these topics: