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breathing and learning - a primer

Suddenly everyone is noticing the importance of what we breathe in our learning spaces. CO2 has got everyone excited, but it is way more complex than just that, of course. CO2 is just one part of the problem.

We have been researching this for many years and offer this short primer to summarize some of the important details. Very much more available of course from website or and from the links embedded below.

If you are in a hurry - just action the green bits below.

pandemics and indoors

In short, ventilate and mask (with some caveats - see below). Ventilate means opening doors and windows. In the graph below you can see the rapid build-up of CO2 (top line) with no ventialtion in first hour of school, the still significant build up (middle 2 lines) with just windows open and finally the healthy flat line with doors and windows open. CoVID droplets and PM2.5 CoVID bearing particles behaves similarly to CO2 - they are heavier and thus sink to the lower half of room (hence doors as well as windows.). CO2 should be monitored and should be comfortably under 1,000 ppm (parts per million).

There is a very clear graphic to help you with things like room organisation here in El Pais newspaper

During our webinar on aerosols in learning spaces the chilling phrase "in you wanted to design a contagion engine, look no further than a school dining room" (large numbers, all speaking loudly, dreadful ventialtion etc) suggests that we should all be looking structurally at how we serve meals into the future. Adding an outdoor serving hatch for example looks like time and money well spent. But it needs a proper rethink.

If fire regs allow it, take as many doors off as you can.

microparticulates PM2.5

These little particles - often associated with the soot from diesel engines - are hugely important. PM2.5 pollution, at really quite low levels, impacts on cognitive performance and, as kids struggle to stay focussed, on behaviour too. Damage is comulative. A study by Xi Chen et al, at Yale School of Public Health in the US, suggested that high levels of urban pollution have a major impact on attainment - some children dropping a whole year of progress in their school lives. That is a bigger learning loss than the lock-outs of this pandemic era! Obviously, you do need to monitor and minimise TVOCs.

High external levels of PM2.5 (eg where the school is adjacent to a busy road with slow moving traffic) would preclude opening external windows and at that point it is down to air filters and plants to improve things inside.

Realy worryingly, many recent studies higlight the role of exposure to PM2.5 in increasing the severity of the impact of CoVID. In short, PM2.5 particles are bad for your health, for your perfomance, for your behaviour. Those fine particles also act as an effective carrier for the virus. And finally if you contract CoVID and come from a higher PM2.5 environment, then you will be more likely to end up on a ventilator. You need to monitor, and mimimise, your PM2.5 readings, inside and out. If you don't have a Learnometer, then IKEA do a PM2.5 monitor.

total volatile organic compounds (TVOCs)

TVOCs are those nasty chemical smells you get - eg when you take the top off your whiteboard pen. They impact signicantly on cognitive performance. You do need to monitor and minimise TVOCs

In an ironic twist the aggresive CoVID cleaning regimes typical of most schools leave an unacceptably high level of TVOCs in the classroom. In this graph the before-school surfaces cleaning sends TVOCs sky high - levels drop a little but stay unacceptably high for about 5 hours unless you can arrange very significant air change.

In two cases we have had to shut (and in one case demolish) classrooms because the TVOC ingress from the foundations below proved impossible to isolate.

Beyond the aggressive CoVID cleaning impact, we have particularly found alarmingly high TVOCs around science preparation rooms and dispensing counters in secondary schools.

You need to monitor your TVOCs, have a thourough look at rearranging scince proep and audit your cleaning materials to mimimise TVOC readings.

impacts on behaviour & performance

With such constant debate about effective behaviour and teaching strategies it seems surprising that something impacting so demonstrably on behaviour and performance would not be central to that converstion and to school policies.

There really are substantial gains on offer here. In the very early days of our research Asha Alexander, head of one of the GEMS schools in Dubai led a a project to cut CO2 in 162 classrooms by adding a plant wall (see Bring Your Own Plant). Below is an image from the staff research - it wasn't just the performance numbers that improved; the individual behaviour for each child improved too, as you can see from this example:

impacts on wellbeing - staff & children

Headaches, absences, stress... so much can lie at the door of poor classroom environments. Even the "wrong" lightbulbs will make you feel poorly. Although all our work is promarlity focussed on better learning and better cognitive performance, if you are optimising those things then you are probably also creating an environment that optimises wellbeing too.

equity and inclusion

In our research we have found substantial differences between learning spaces to the extent that there is a clear equity issue. Measuring over 80 exam rooms we have also found substantial differences between different parts of the room. Profoundly unfair.

We are just beginning a project optimising the home learning / working space in 4 coastal community family homes in areas of profound deprivation. Our hypothesis is that with relatively cheap interventiosn we can level up opportunity. Follow our website or @stephenheppell on Twitter for progress.


Our work extends to nutrition, light levels (hugely important), to sound, to olefactory stimulation, temperature (keep between 18 and 21°C) and more. Much of this amounts to performance, test and behaviour gains just waiting to happen, when the right details are in place.

25 million people on our server last year - have a look yourself - this page is just a primer. And buying a Learnometer would not be a bad idea too.




Prof Stephen Heppell of UCJC
this page last updated on Saturday, August 21, 2021