Thread by @joeyfox85

#covidco2 HOW CAN CO2 MONITORING HELP IN SCHOOLS? 🧵

When humans breathe out, 4-5% is CO2. If you are in a poorly ventilated area, it builds up. Measuring CO2 in a room tells you how much air has already been breathed in.

1/25

https://twitter.com/DavidElfstrom/status/1468268425617330185?s=20

COVID spreads by breathing in air that an infected person has breathed out. It makes sense to closely monitor the CO2 levels. Higher CO2 levels indicate a higher risk environment where you are more likely to get infected.

2/25

If you are going to a public place with other people, you want to reduce your risk as much as possible. By monitoring the CO2 levels, you get a good assessment of your risk. If you are indoors with other people, it's best choose a place with lower CO2 levels.

3/25

SCHOOLS

You can choose a restaurant or a museum and if the ventilation is poor, go somewhere else. Kids and teachers can't.

I've previously expressed skepticism about successful implementation, but it can be helpful. Here are some uses.

See also:

https://twitter.com/Poppendieck/status/1456461078041333760?s=20

4/25

WINDOWS

Opening up windows is a good way to always get fresh air. There are limits if it's cold outside. A CO2 monitor could let the teacher make decisions about opening and closing windows.

5/25

However, I think people don't realize that aside from professionals and those reading this on twitter, very few people understand CO2 levels and ventilation.

School boards are still banning respirators. Would they spend time training teachers about CO2 monitoring?

6/25

If it works, then great, but before sending out CO2 sensors to all classrooms, school boards and teachers would need to get on board with this.

I've seen how HEPA filters are used. They are left in the corner of the room and turned on low speed. This could be the same.

7/25

MAINTENANCE

A parent used CO2 monitoring to identify a broken air handling unit (AHU) and get if fixed. (Can’t find the tweet)

It can work. But that is only if the parents are given this information and not if it is just left in a classroom.

8/25

Equipment should be maintained properly and much of my job is trying to make this happen. Due to a historic culture, maintenance deals with complaints which originate from thermal comfort, not ventilation.

9/25

To be fair, maintenance is understaffed so this is expected. This isn’t just schools, it’s everywhere. People care about the heating and cooling working properly because it’s readily noticeable, but ventilation is always neglected.

10/25

CO2 sensors drift over time or get dust on them and loose accuracy. They need calibration or replacement. If monitoring CO2 is a long term goal, it would significantly increase maintenance work. I don’t see this working.

11/25

Almost all school boards have a building automation system (BAS) to control the equipment. I’ve designed and installed BAS for many schools across the GTA.

Broken AHUs can be seen remotely. High CO2 will be telling you what you should already know.

12/25

My kid’s school has no BAS. The roof top units that supply the ventilation were never setup properly. Here, monitoring CO2 can let you know if the dampers need to be adjusted. Any school like this would greatly benefit from CO2 monitoring. This isn't too common.

13/25

IMO, if the mechanical systems can already be well monitored, then there is less need for CO2 monitoring. People don't realize that this is already the case at the major school boards.

For schools without this capability, then CO2 monitoring is very appropriate.

14/25

RECESS

Maybe if CO2 gets too high, take the kids out for recess. IMO, we should be taking them out for recess more anyways. I'm not a teacher and don't know if adjusting the schedules is really possible, but even without CO2 monitoring, we should be maximizing recess.

15/25

PARENTAL KNOWLEDGE

Many are learning how to protect themselves from COVID. Knowing the CO2 level in the classroom can give you piece of mind or make you worry (understandably). Schools would need to disclose. But that wouldn't necessarily change anything.

16/25

POLITICAL WILL

Once there is more education about poor ventilation in some schools, we can get more will from our leaders to fix it. Unfortunately, the only option is demolishing and rebuilding around 20% of schools. Easier said than done.

17/25

EDUCATION

This is what school is about! Get the teachers and school boards on board! Teach everyone about monitoring CO2. Stay healthy with clean air, reduce risk of getting COVID.

But a change needs to happen in acknowledging #COVIDisAirborne, otherwise it's a waste.

18/25

EMPOWERING TEACHERS

If there are ventilation problems, the teachers could notify the principal which might be more effective to get it fixed. Teachers would need to get on board. This wouldn't do anything at schools with bad ventilation in the first place.

19/25

CONCLUSION

I might have missed some possible uses. I think people with their heart in the right place want CO2 monitors in classrooms everywhere. But I believe before putting CO2 everywhere, we need to know what we will do and ensure it can be done.

20/25

Every school is different. There are some situations where it can be very helpful. In many situations, I'm skeptical about how beneficial it will be given the tools we already have, limitations of the building and school board acknowledgement of airborne transmission.

21/25

School boards across Canada still ban respirators and HEPA filters. It’s cruel. If they can’t get that right, I’m not optimistic about CO2 monitoring.

Now, we could offer CO2 monitors to teachers that want. If it's just placed in every classroom, it will just be ignored.

22/25

This is about a societal change. People need to get on board with clean air and airborne mitigation. If no one cares about the treatment, then the diagnosis is pretty useless. Once people care, lets put CO2 monitors everywhere!

23/25

I acknowledge I come at this from a perspective of someone who designs and commissions HVAC systems for schools and sees how it operates. I have no control over operations, so it’s made me jaded.

I hope everything changes now.

24/25

Final thing. The people in charge, especially public health, have no desire to listen to anything engineers have to say. School boards blindly follow public health who are still denying #COVIDisAirborne

Fin

25/25
@DavidElfstrom @joeolivermd @imgrund @Fix_Our_Schools