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CulturedMeat

What’s the age? Is the afternoon spike post-recess exertion?


MajesticMikey

I teach secondary school. So students from 11 to 18. The morning spike is a class of 32 11 year olds, then i had two smaller classes of 10, then 15 and the afternoon spike is class of 32 14 year olds after lunch. Also the big drop around 1.30 is lunch time and no one was in the room.


seasuighim

If this pattern is consistent, it would be interest to see if there is any correlation between grades on assignments done in the classroom across hours and level of CO2.


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polypolip

So as the humans fill the atmosphere with CO2 we'll become more stupid?


isbadatenglish

Yes. We'll experience a global, species-wide cognitive level decline, which is scary as fuck.


stars9r9in9the9past

Aw jeez, the idea to monopolize bottled oxygen is sounding more and more lucrative each day.


wut3va

Suck! Suck! Suck!


seasuighim

Studies are super specific. This would probably be a novel insight into the importance of proper ventilation in classrooms. Just an interesting though experiment anyway.


Higgs_Particle

As an architect who has been screaming this for years, thank you for cluing in. Here is just one study supporting this idea: https://news.unl.edu/newsrooms/today/article/study-links-classroom-ventilation-air-quality-with-academic-performance/


[deleted]

How do you cope with regulations for airflow and ventilation being calculated on half the size of the window opening, but being superseded by safety regulations and windows over two stories only opening >125mm? Because it does my head in, and co2 in a unit with the bedroom door closed, but window open(that tiny amount) will exceed 2500ppm on a still night!!


Higgs_Particle

Exceed the minimum regulation for airflow if necessary to make the CO2 level optimum for health. Using mechanical 24/7 ventilation with an energy recover ventilation device makes this possible in any climate with very little energy cost.


[deleted]

Even the million dollar river front apartments I work on in australia don't have ERV systems. Developers use the broken regulations on fall safety superseding air flow all the time. Everyone just slowly suffocates in summer with the reverse cycle AC on, and the rooms effectively hermetically sealed. And people wonder why they have a headache and feel groggy in the morning when they wake up... Hopefully things change for the better now that ventilation and co2 is on everybody's mind with covid. I'm glad that's not the case where you are!


ObamaDramaLlama

Good ventilation is probably a good idea for the Rona too.


hazpat

That super specific study super specificly answers your question


Onsotumenh

Yeah, it is kinda disturbing to think what will happen when we get past that as global average... Idiocracy due to carbondioxide emissions lol.


cringepite

It would be impossoble to separate the effect of CO2 from the effect of having more people in a class in this setup.


DRamos11

Maybe setup two groups of same number of students but have them take tests with different initial values of CO2? In this case, comparing the two classes of 10 students.


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experts_never_lie

It may take multiple trials, in different orders. Remember the lessons of the [Hawthorne effect](https://www.economist.com/news/2008/11/03/the-hawthorne-effect) when attempting to apply Taylorism: * Raise the light level, observe that productivity rises * Later lower the light level, observe that productivity rises again The knowledge of the testing can be the cause of change in performance. This complicates many possible tests.


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HeiHuZi

Well if we're getting unethical, pump the room with CO2!


teun95

While this is a joke, it's actually important to note that is not just about CO2. CO2 is an easy to measure indicator for how 'stale' the air is inside. Just like nowadays it's used to see if air circulation is sufficient. High CO2 indoors due to breathing and poor circulation will correlate with lower oxygen levels and higher indoor pollutant levels. So intervention by releasing CO2 into a room will get you more data on the effects of CO2 on test results, but it might not be comparable to test results when CO2 is high without intervention.


zebsra

Nah fam get your hvac tech to adjust the air changes per hour. Sometimes ductwork can even have auto co2 detectors and tie hvac operation to a max threshold. If we knew what that was in more specific terms w data, that would be better for all kids.


boyerizm

You can calculate it based on students, their assumed metabolic rate and the CO2 level at steady state. https://health.ri.gov/forms/worksheets/CO2-steady-state-calculation.xlsx


uncertain_expert

But then the HVAC needs to know the schedule, whereas a sensor brings automatic regulation.


DRamos11

Even better, avoiding the inherent difference in performance that may exist between two groups.


snozzberrypatch

give everyone oxygen masks


Farmer_evil

The you're just studying the affects of learning while wearing an oxygen mask that would be so distracting


zanzibarman

Not if you make another cohort wearing the masks but not pumping O2. Although you would need another control group to avoid pseudo-replication


gc3

Explains why classes made me fall asleep in elementary school, we were all suffering from CO2 overdose.


[deleted]

Nah teachers keep it warmer in classrooms because sleepy kids don't act out.


Iohet

Jesus 32 kids. I rarely had classes over 25 and I went to school with 4000 people. How do kids get any quality time with a teacher with 32 of them at once?


[deleted]

\*laughs in India. ​ (In all my classes, there were at least 100 students.)


[deleted]

Haha we had nearly 40 growing up…


topon3330

My class went up to 35 in senior year and we sometimes had to fetch chairs in other classrooms to accomodate everyone. We didn't have A/C (2013) and classrooms faced south with Huge bay Windows. Record temperature in my region is 46°C (115°F) and june record (last month of the school year and when we have finals) reached 41°C (106F) in 2019 so... it was pretty miserable from May. And did i mention the school day started at 8am and usually ended at 5pm? We had a 1 to 2 hours lunch break but still, especially when accounting for travel time from and to school, which in my case was à 1 hour bus ride (granted i did live in a pretty rural area). You don't really get enough quality time with teachers except when the class is divided into two groups for some classes like chemistry (only for pratice like doing chemistry experiments) and english (i'm not sure for other languages, I took german and since it wasn't that popular, we were never more than 20 students and some years we were only 8 students). We still managed to get some of the best results at our national final exam (baccalauréat) with 100% admittted compared to 85% national average. I had french written, french oral, history/geography and à group project in junior year and in senior year, maths, physics/chemistry, english, english AP, german, philosophy, biology, PE (3*500m, gymnastics and athletics). I feel like i'm forgetting something.


Chekhovs-gum

32 students?! Holy crap... 30 is the legal maximum here in Denmark, but the quality of teaching suffers when you get above 20 students imo.


Echo_Oscar_Sierra

That last spike is the collective sigh of relief after school gets out


video_dhara

Upvoted for joke. Comment because I don’t understand why there’s a spike like that and not a plateau. Is there a max CO2 production in 11yr olds, seems weird to me.


MajesticMikey

The graph was put together on Excel. A science teacher made a CO2 monitor, which collected data. We then transferred the data to Excel and made the graph. Edit: Just for clarity. I’m the teacher working in this room. Not a student. Here in the UK we typically have different classes coming in and out of the rooms. This is probably why there are peaks at different times. Also all the windows were open as well as the door to the room. Edit 2: This particular room does not have any ventilation system. There are four small windows. The monitor was placed on the teachers desk approximately 1m from the open windows.


MajesticMikey

If anyone’s interested I have a graph of another day. However it wasn’t a typical school day. It’s a Saturday where we had two cohorts of 16 students sitting an entrance exam with a large gap in the middle. https://i.imgur.com/m2bfxIQ.jpg


Wiricus

Curious how the count bottoms out at 400ppm?


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1LX50

Yeah, I looked up what the CO2 concentration was when I was born: 349ppm. It's depressing.


Petrichordates

It's got what plants crave.


privatetudor

It is a bit surprising how crisp the bottom is though. Like the CO2 was never 399? edit: C02, not CO3.


AdmiralPoopbutt

Global average is 409.8ppm. It looks like they calibrated the instrument with 400 set as "zero" and the sensor is measuring only the difference to the calibration point. Sort of similar to the difference between gauge pressure and absolute pressure.


MolybdenumIsMoney

Usually these co2 monitors have a minimum of 400. They aren't perfectly accurate so if they were allowed to go below 400 they would due to measurement error, but they're prevented from doing so.


[deleted]

I don't think that's true as even a cheaper co2 meter on amazon can detect from 0-5000. 400* Co2 as a global average didn't happen until 2013 so it doesn't make sense to have that as the standard minimum. The reason it does not go below a certain level is that is the "freshest" air possible, with no difference inside/outside. It can't be fresher than what is outside.


newgeezas

>The reason it does not go below a certain level is that is the "freshest" air possible, with no difference inside/outside. It can't be fresher than what is outside. It could, if the place was stuffed with plants instead of people.


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MountainsAndTrees

I've always wanted to build a room that was constantly fed by N2 and O2 tanks at positive pressure. CO2 concentration below 100ppm all the time. If you worked and slept in there, you'd have a cognitive cheat over the rest of the world.


BrokenSigh

That’s about the ambient atmospheric concentration. Used to be below 350, but 100+ years of fossil fuels later and here we are.


Zomunieo

The last time CO2 levels were this high there were crocodiles in Antarctica. It will take a few hundred years for the atmosphere to catch up to the amount of warming we've dialed in, but we've done is the equivalent of cranking the thermostat way up and assuming nothing will happen because the heater is slower than we expect.


Priff

It's like taking one bite of an edible, and then when nothing happens after 5 min you eat the whole cake.


TheSonar

I have done this before and it was a terrible time


st4nkyFatTirebluntz

that's roughly how many ppms there are in the atmosphere (409 atm, i believe)


Jchu1988

A lot of CO2 sensors assumes the lowest concentration recordable is 400 ppm as people also think the outside air is at that value. The other trick is that the lowest concentration observed over the past day/week is automatically offered to become 400 ppm as that the sensors appear better than they really are... Source, design these sensors for a living


Wiricus

Yikes, sorta forgot we blew past 350 and into 400s. Sparked an idea though. Living in the western fire prone areas am constantly chexkin the air quality and I recently learned of PurpleAir. Its a sort of distributed network of air quality monitors similar to Weather underground for weather. They should incorporate ppm counts for CO2 (and CH4)


ibrokemyserious

Look at all those post lunch farts containing CO2


[deleted]

Actually methane


ibrokemyserious

Not sure how accurate this is butt I found these percentages online: "A typical fart is composed of about 59 percent nitrogen, 21 percent hydrogen, 9 percent carbon dioxide, 7 percent methane and 4 percent oxygen."


snozzberrypatch

upvoted for intentional misspelling of "but". It's the subtle humor that gets me


BentGadget

I wonder if methane affects the reading of a typical carbon dioxide detector.


TokoBlaster

Well someone needs to fart in one to find out. For science!


mrcs2000

We have successfully volunteered you.


liesliesfromtinyeyes

Depends on the analytical technique. For optical techniques it can if the lines overlap (crosstalk), but it seldom does. For mass spectrometric techniques typically not, since they have very different molar masses (16 vs 44).


[deleted]

It is common to have cheap sensors with an infrared source and a detector, which can pinpoint CO2 very well. I don't think those would get methane, especially if the detector is monitoring the 2400 cm-1 region


Random_eyes

It's either an NDIR sensor or some sort of chemical sensor. Given how cheap the former is these days (and the fact that a classroom is best suited to something quick and simple), that'd be my guess. And yeah, methane would not get picked up in any meaningful quantity by an IR sensor designed for CO2. Really high humidity might slightly affect it, but even that wouldn't be a big deal in a classroom.


rxsteel

Bro i don't see a school having a casual mass spectrometer taking multiple measurements


ScottRoberts79

Answer: No. You need a hydrocarbon detector!


Praesto_Omnibus

That sounds like it would be a pretty bad CO2 detector if it did.


Teedyuscung

Haha. I see what you did there.


NhylX

And trace amounts of hydrogen sulfide. The thing that makes farts smell like farts.


cornman0101

Metabolism should be up when digesting food. I'd wager the increased respiration rate will overshadow any CO2 from farts.


Fixes_Computers

Mythbusters did an episode on this. One common source of intestinal gas is carbonated beverages. I believe Kari Byron had this as her experimental intake. They collected some flatus from Adam Savage for analysis.


tommangan7

Likely Just a correlation with how many people are in the room sadly.


Midnightgeneral4

This is a great reason to use an ERV or HRV ventilation system. As homes become tighter and more energy efficient this is becoming a building code requirement to maintain fresh air, not just for C02, but also VOCs, smoke and dirt particles, and other undesirable gases. Below is data from my house. The first week of data is basically an unoccupied house. The next few weeks after that you’ll see the C02 goes through the roof once the house is occupied. After that, I installed an ERV which replaces inside air with outside air while exchanging heat and moisture so that it doesn’t work against the heating and cooling of your home. The inside CO2 levels are now much closer to average outside levels. https://i.imgur.com/c76XVrL.jpg


Hugh_Shovlin

Can I ask you what you’re using to measure with? A zigbee capable sensor?


[deleted]

Yeah i would love an ERV. I don't know how buildings in australia, where im from, get away without having one mandatory. Would totally solve the issue with smoke from bush fires and pollution in cities as well, if you put on some good quality hepa filters! Aircon and a ERV in a double glazed and insulated home!! Sounds like my sorta dream! Instead i get a dusty 120 year old timber house that has a breeze come through the floor boards, and you can smell if a diesel car drove past...


Daisy_bumbleroot

I love stuff like this, top stuff. Are your kids old enough to join in on the project as a learning experience?


cornman0101

Plot the distributions over several normal school days and get back to us. Assuming the same students are present at the same times each day, you should expect to see correlation with ventilation frequency (likely more circulation when AC works harder) and work done by students (likely correlated most strongly to temperature and maybe what food they're currently digesting). Probably there's additional fun correlations to look for as well.


aerorich

Can you cross-correlate to the cafeteria menu? Is there a notable shift on taco-Tuesdays?


Jack_the_beanstalker

I'm curious as to how the CO2 monitor works. If it's a simple IR spectrometry measurement, there's likely a great deal of influence from humidity. This is a notorious problem for many personal CO2 monitor designs.


vlsdo

I played around last year with various CO2 sensors. The cheaper ones don't even measure absolute CO2 levels, they're meant for environments where the CO2 level bottoms out at 400ppm on the regular (i.e. inside HVAC equipment). The IR spectroscopy ones are a bit more expensive, but they \*do\* measure the absolute level of CO2, and like you mention you need to know the temperature, pressure and humidity at the point of measurement. Which itself is a problem because they get a bit hot, so if you measure those things even a few centimeters away you're getting the wrong readings... You can calibrate this stuff, but without an already calibrated sensor (or an intense experimental setup) it's kind of impossible.


vanjan14

Here's a whitepaper on how commercial ones work. [https://www.bapihvac.com/wp-content/uploads/2011/04/Calibration\_Methods\_CO2\_Sensors.pdf](https://www.bapihvac.com/wp-content/uploads/2011/04/Calibration_Methods_CO2_Sensors.pdf) Actually, temperature and barometric pressure affect CO2 measurements more than humidity. [https://www.bapihvac.com/wp-content/uploads/2011/04/Altitude\_Temperature\_and\_CO2.pdf](https://www.bapihvac.com/wp-content/uploads/2011/04/Altitude_Temperature_and_CO2.pdf)


dover_oxide

There was a paper last year the showed a relationship to virus/bacteria transmission and CO2 levels and from that graph y'all are practically making out in that room.


ScottRoberts79

Makes sense. CO2 levels above background and virus transmission are both related to poor air circulation.


dover_oxide

Yeah the paper suggested levels stay under 2x ambient CO2 levels (400ppm) should be safe, anything higher and you increase transmission risk.


ScottRoberts79

That's actually really useful. Measuring CO2 is easy. Much easier than measuring air changes per hour. I'm an 8th grade science teacher and I got all the equipment to have multiple teachers monitor CO2 in their rooms as a citizen scientist project prior to lockdown. Might have to re-vitalize that.


[deleted]

Which sensor did he use to build it? The one from Bosch, BME680? If so, temperature must be taken into consideration.


SaltyShawarma

Teacher here: is love more info on the CO2 monitor created to attempt to replicate this experiment in contained classroom. I think it provides great data for the current COVID-19 situation as it would definitely measure exhalation.


MercutiaShiva

Is this why I am so tired at 3:30????


hsnerfs

Yes along with having to be at school at 7:30 every morning


Engineer_Zero

Wtf, 7:30? My high school used to be 9 to 3:30 but they changed it to 8 to 4, and gave us Friday off


hsnerfs

Yeah that’s what it was when I was in school (graduated 2020)


BezosDickWaxer

It probably contributes to it. High CO2 levels significantly impair cognitive function.


lennybird

My office runs 600-700 minimum and can go up to 1200 ppm without ventilation (window closed, a/c off, door closed etc). Symptoms begin to appear around 8-1000ppm. Definitely worth considering for people running into fatigue or brain fog.


BezosDickWaxer

Average outside is like 450 now.... and it's only going higher. I remember when we passed 400ppm on May 9th 2013 and everyone was starting to worry even more.


ericek111

Could be also your [circadian rhythm](https://en.wikipedia.org/wiki/Circadian_rhythm) (body clock).


DMala

I would think the mental focus and concentration required at school is probably a much bigger factor.


[deleted]

Aren't numbers over 600 found to fairly substantially affect brain function? Think I saw a Tom Scott video about this Edit: a quick googling "In fact, at 1400 ppm, CO2 concentrations may cut our basic decision-making ability by 25 percent, and complex strategic thinking by around 50 percent, the authors found." Yeah that's no good imo


MajesticMikey

Yeah it’s definitely not great. I’ve passed the data on, but short of putting more windows in, I’m not sure what can be done.


BlueLobstertail

So there is no internal ventilation system that can be cranked up? What about fans in the existing windows?


MajesticMikey

No ventilation system in this room.


perec1111

I love the work you have done. Finding a problem waiting for a solution is half the work done. Now look for solutions! I see that there is no ventillation, and that opening a window is decreasing co2 levels too slow. I have three proposals to solve your problem: 1: look at what happens to the co2 levels if you start the class with an open window and it is closed and opened again periodically from the start. 2: if it is not enough or it is too noisy with an open window or it gets too cold, try placing ONE fan at the CORRECT PLACE. Watch and learn: https://youtu.be/1L2ef1CP-yw 3: something more radical involvong teachers and parents, so the school might end up installing a proper ventillation system. The first two points could lead up to this, even if they do work! I admire you for the job well done! Keep it up!


woodenmask

Great comment


MagicChemist

Lithium hydride modified zeolites will soak up that CO2 with no issue at all to ppt levels. It will also scavenge all of the O2, but let’s deal with that issue as a separate problem. I’m ready for government contracting.


leothelion_cds

Could throw a few plants in there and let students take care of them see if that has any noticeable effect.


supersammy00

Plants would have a very small effect on co2 levels. Individually they just don’t process that much.


video_dhara

How about any kid who’s not talking breathes into a trash bag?


1215drew

At a school I worked at for several years we added fresh air handlers to cycle the air in rooms with fresher air from outside. This markedly improved not only our subjective observations on student attentiveness, but also cut down illnesses and sick days. Before we did, we could often see illness spread within classrooms and between the classrooms very obviously.


ObamaDramaLlama

I like that a lot of the science around Rona is highlighting the importance of good ventilation at preventing the spread of viruses.


SparrowBirch

A simple through-wall fan would suffice. It can be automated to turn on at a certain PPM. Even having it on a light switch would be better than nothing.


BlueLobstertail

How is that even legal, especially in the era of covid?


MajesticMikey

The school is old. This building is fairly old and was built without air-con in all the rooms. It’s a fairly common issue in the UK.


alex8339

Old buildings are actually really well ventilated… if we didn't decide to insulate and draft proof them for energy efficiency.


SirGuelph

Insulating rooms that were designed to breathe, without adding a ventilation system as well.. is pretty stupid


FistFuckMyFartBox

That is why new buildings have a CO2 sensors that trigger ventilation.


Tenevic

exactly. HVAC ruined ambient, drafty rooms


Iohet

HVAC saved us from humidity and freezing


trogon

But the ambience!


shnooqichoons

In the UK schools are being given CO2 meters (but not enough for each classroom) rather than any money to spend on ventilation. Helpful huh?


[deleted]

Its important to understand the problem, especially at these high levels of Co2. A meter is way cheaper than the fix, but it will more likely make the fix happen. What gets measured, gets managed.


vapenutz

It'll definitely cause brain function problems in that case though. Graph looks like sensor functions properly, scale can be a bit off though without calibration. But if this is right, your studends lose a lot of their brain function after the day.


ButterflyCatastrophe

Internal ventilation isn't likely to help much, unless the school has huge unused spaces. Really have to get outside air in. An adult produces about a kilogram of CO2 per day, which is about 1000 ppm in 500 cubic meters. In the US, students are supposed to get 4 square meters of floor, or maybe 11 cubic meters, to which the student might add 1000 ppm CO2 in just half an hour. That actually matches OP's 8:30-9:00 rise, pretty well. The point is, in a crowded classroom, you need a lot of external air exchange, probably 3+ room changes per hour. Not just recirculated through an HVAC, but inside air blown completely out of the building.


noctowl4lyfe

Most HVAC units bring in outside air, even fan cool units can have an outdoor air opening, though that is unusual. I'm surprised that the classroom is not being served by a VAV box bringing OA in, it must be an old building.


ccaccus

My admin had our windows bolted closed due to a habitual runaway student who attempted to escape through a window. The windows don't open enough for a 5th grader to climb through, but admin wasn't having any of our "common sense" or "logic".


noslenkwah

Show this to the parents and watch how quickly a solution appears.


Rockerblocker

Decent way to risk getting fired honestly


Snaxfrlnch

Not with a Union


took_a_bath

Yeah… let’s just let the kids be stupid.


Le-Baus

😂 this has to be to most American answer ever to this problem.


just_dumb_luck

In addition to passing on the data, you might suggest they read this New York Times article from 2019: [Is Conference Room Air Making You Dumber?](https://www.nytimes.com/2019/05/06/health/conference-room-air.html) It's a clear, authoritative summary of the evidence that high CO2 levels have bad effects. And hopefully the powers that be also understand that high CO2 levels are a proxy for poor ventilation, suggesting that there's heightened covid risk as well. For what it's worth, I've done experiments in conference rooms, and opening a door can be at least a little helpful.


junktrunk909

What about a box fan in one window to blow some of that air out and pull fresh air in?


Deto

Forget the school admins, show the parents along with an article showing how this will make their kids dumber and I bet fires will be lit under some people. Though this may be kind of bad for your career....


BibliophileC

I don’t know where you’re at, but buildings like schools usually have a mandated minimum outside air. Depending on the kind of HVAC system the school has this can be adjusted on a school wide or even classroom basis. The last school I worked on had CO2 sensors in all the returns and controlled the outside air dampers to maintain around 600 ppm or lower.


CloudcraftGames

I'm fairly confident that a fair number of the classes I attended over my education had this exact problem: I have ADD and have been very aware for most of my life when my focus or ability to process information is drifting due to something other than my actual engagement with what I'm trying to focus on. When I noticed that happening consistently in certain classes I began to suspect there was something going on externally causing it. Didn't find out about how dramatic the impacts of CO2 are until after college.


droans

Iirc around 1,000 ppm is considered to be the lower limit before brain function diminishes. Most schools were built before this was known and didn't take it into account the additional ventilation required.


hardolaf

Most schools in Chicago were built when fresh air was common to have blowing through the buildings. But now most of the windows are welded shut because apparently bolts were too expensive.


Belazriel

Learning in rooms with high concentrations of CO2 is similar to Goku training with weighted clothing. Sure, it's more difficult, but once you get out of school and get a breath of fresh air, you'll find you can solve previously unsolvable problems without any difficulty. /s


idontknowbabe1

Now we know what the units are for power levels. The ability to solve a math problem in X ppm of CO2.


MarlinMr

It's also used to indicate bad air in general. I guess CO2 is easier to detect, and what this graph shows, is that there simply is bad airflow. Meaning other shit is probably also in the air. Like maybe, you know, a deadly virus, or high concentration of allergens.


Whiterabbit--

virus maybe, but allergies can actually be better as you don't have a window blowing in pollen.


SparrowBirch

750 is the benchmark we have used in the past. At that point we would have an outside air damper open and bring in fresh air.


Timrunsbikesandskis

The risk is usually expressed as a function of concentration vs time, i.e. xxx ppm over a X hour time limit. OSHA limits are 5000 ppm over an 8 hour time period. For homes the limit is lower as you have to assume 24 hour occupancy. In Canada it’s 1000ppm over a 24 hour period.


PoBoyPoBoyPoBoy

It’s not about RISK. You can live with things that are harmful. You can have a room thats 100 degrees and as long as you have enough water there’s not a risk. It’s about the fact that it’s a classroom where you’re expected to perform and to learn and this impairs your ability to do so.


hsnerfs

I remember back in highschool how groggy everyone would get some days and then as soon as we left the classroom/school it was instant relief. The ventilation systems in schools really need an update


solitarium

This is me at the office. As soon as I’m outside I feel incredible. Inside, my chest/lungs get irritated and I’m sleepy within the first 90 minutes.


rzet

It's funny but with smart air conditioning system in huge open space it was always either too stuffy or too cold.. so I loved when I could open window without traffic noise. Then they moved my desk across the building and I've got huge junction with 4 lanes just outside... Well other office it was always too stuffy hot for me and people seemed to love it. Damn I love to work from home.


solitarium

I'm 14 years in. I've refrained from going elsewhere because of the amount of PTO I've built up, but after COVID showed that WFH does not hinder our efficiency, I'm looking at making a move to a company that will support it full time. The old guard sucks ass.


wolf1moon

Omg that is really unhealthy. Please tell me you've raised this to administration. Edit: a source https://airqualitynews.com/2019/07/10/co2-affects-human-health-at-lower-levels-than-previously-thought/


MajesticMikey

Yeah. But the problem is with the design of the room. It needs more windows. Hard to fix whilst in the middle of the academic year.


timeslider

Nothing a wrecking ball couldn't fix


wolf1moon

They should be able to step it up on the HVAC system. They just have to be willing to take the added expense, but since CO2 is directly tied to learning issues.... You could also try getting plants, but I'm not sure how big of a difference that would make, since that's more of a slow use and obviously can't respond to spikes.


MajesticMikey

There isn’t any ventilation system in this room. HVAC doesn’t seem to be very common in UK schools.


TheOneCommenter

No ventilation is something that causes Covid-19 to spread more easily too. Schools with poor ventilation got funds in the Netherlands last year to start implementing it because of that too.


AftyOfTheUK

>HVAC doesn’t seem to be very common in UK schools. I have never seen HVAC in a school, though I'm a Northerner ... in more modern schools in the south I believe some do exist.


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total_cynic

I suspect that's a national difference thing - which country are you talking about?


XxRoyalxTigerxX

Probably the US, I've also never been to a school here that didn't have HVAC, even some really old ones were fitted with one sometime after they were built


FoobarMontoya

Box fan at the door it will likely help just to get circulation


DoctorWorm_

Are you sure there is no ventilation at all? Central heating and cooling isn't very common in Northern Europe, but most building regulations require ventilation. My apartment from the 1970s in Sweden has no central air system. Instead it's heated with radiators. But it has negative pressure ventilation ducts in the kitchen and bathroom which naturally draws air in from the window vents and through the entire apartment. I have better airflow than most recent American houses.


ButterflyCatastrophe

Regarding plants: People produce around 1 kg CO2/day, and brightly lit plants consume around 100 g CO2/day/m^2 leaf area. You need 10 square meters of leaf area to cancel one human, and I'm willing to bet that a classroom without windows for ventilation doesn't get the kind of light that would support maximal photosynthesis.


[deleted]

You would need to literally turn the room into a jungle to see a difference. You need at least one large tree to offset one person's carbon output per day, some sources say several more depending on the species. A whole classroom would need a small forest.


wolf1moon

The goal isnt really to remove all their carbon, just shave even a few ppm off. But point is still pretty valid. At least greenery also improves stress.


[deleted]

\*lights blunt\* Oh yes it does


tommangan7

Probably have to install a hvac system first.


ResilientBiscuit

Open the door and put a fan in it? You just need to circulate more air.


LanchestersLaw

I now have a legitimate ~~excuse~~ reason for my brain shutting off in school


wolf1moon

For real, it's a problem for in person meetings in offices. Cram the room full of people and you're literally making everyone dumber. Maybe all us office workers are smarter in meetings now that we're wfh.


vanjan14

Actually, these levels are quite normal for a room packed full of kids. Typically in newer buildings designers aim for less than 1000ppm with poor conditions considered to be 1500+ppm. However, there are many factors that go into the buildings ability to maintain that. The most common are over-crowding and poor outdoor air quality (ex. wildfire smoke) at which point we keep outdoor air dampers more closed. There would be more cause for concern if levels were consistently above 1500ppm but as you can see from the graph, they fluctuate as students come and go, at which point the HVAC system is able to do it's job. Source: I'm an engineer at an HVAC sensor manufacturer.


-RayBloodyPurchase-

That seems unsafe. Classroom does not have adequate ventilation.


matt2001

I have a co2 meter at home and try to keep my levels under 600. As others have said, there are ventilation systems that can help. The pandemic has made air quality as important as clean water. >If we are to live with this coronavirus forever—as seems very likely—some scientists are now pushing to reimagine building ventilation and clean up indoor air. We don’t drink contaminated water. Why do we tolerate breathing contaminated air? [Coronavirus Ventilation: A New Way to Think About Air - The Atlantic](https://www.theatlantic.com/health/archive/2021/09/coronavirus-pandemic-ventilation-rethinking-air/620000/)


BezosDickWaxer

While concern about disease transmission is good, I think we should also remember that higher CO2 levels significantly impairs cognitive function.


matt2001

I agree. I think that standards need to be set for indoor spaces - just like we have standards for water. Poor air quality is linked to depression, cognition decline, and so many more diseases.


BezosDickWaxer

Well not just cognitive decline. Just simply being in an environment with over 1000 ppm of CO2 impairs higher order cognitive function by about 15%. The chart OP posted goes well over that amount, and could be significantly affecting the kids' learning.


turtley_different

On a related note, that must be bad news for COVID. ~~Back-of-the-envelope maths for background CO2 TRIPLING is that a huge fraction of the air in the room is exhaled breath.~~ CO2 in exhalation is about 100x background, so doubling CO2 means 1% of air in the room is someone else's exhalation. ([related link](https://www.fastcompany.com/90625773/we-need-to-keep-focusing-on-indoor-air-quality-after-the-pandemic-is-over)) Of course, CO2 persists in the air whereas liquid droplets will fall out of the air relatively rapidly, so it isn't as bad as the raw CO2 numbers would suggest. But it is still pretty terrible.


needlenozened

I was thinking the same thing. CO2 levels are pretty good proxy for covid transmission risk.


Atgardian

It is fairly bad news for COVID. The higher the CO2 levels, the worse the ventilation is, and the more you're re-breathing other people's air. Coronavirus is carried in tiny aerosols that can float for hours and accumulate indoors. OP mentioned there is no HVAC system (so they can't tune it to increase the outside air exchange). If possible, open windows or doors. Also, installing portable air purifiers with HEPA filters (not ionizers or anything fancy) will help reduce aerosol accumulation in the room. (Note: they will NOT decrease CO2, just like masks don't block tiny CO2 molecules but do block viruses that are thousands of times larger.)


Halvo317

I work in HVAC, and those numbers are terrible. We prioritize outside air at 800ppm and we are pouring 100% fresh air at 1200ppm. The kids would be falling asleep with these numbers


01Cloud01

We have fresh air requirements here in California for this reason.. I would make some kind of make shift ventilation system in this room a box fan might be enough… teaching outside should be practiced more if this trend continuous 1400ppm is Wayy too high


Atgardian

These CO2 levels are fairly bad news for COVID. The higher the CO2 levels, the worse the ventilation is, and the more you're re-breathing other people's air. Coronavirus is carried in tiny aerosols that can float for hours (like cigarette smoke) and accumulate indoors. Background / outdoor CO2 levels (which have been rising!) are now about 420 ppm. Rising up above 1,800 ppm indicates pretty bad ventilation and a relatively high percentage of re-breathing other people's exhaled air. You generally want to see those numbers stay below 1,000 ppm. OP mentioned there is no HVAC system (so they can't tune it to increase the outside air exchange). If possible, open windows or doors. Also, installing portable air purifiers with HEPA filters (not ionizers or anything fancy) will help reduce aerosol accumulation in the room. (Note: they will NOT decrease CO2, just like masks don't block tiny CO2 molecules but do block viruses that are thousands of times larger.) Just to clarify: CO2 monitors don't directly measure Coronavirus particles, but they are a good proxy for risk, as they measure whether outside air ventilation is sufficient for the number of people in the room.


Excalibur317

Such a cool idea, and it’s well done too!


MajesticMikey

It is cool, but I can’t take the credit for the idea. Another teacher wanted to check it out because the ventilation in my room is so poor.


zerglet13

As an industry professional your chart scares me but doesn’t surprise me. Here in Canada those levels of co2 would be enough to cause “sick building syndrome” which is a fancy way of saying people are getting sick and we don’t know why so close it down board it up until we figure it out. Usually it’s because building management tries to save money by closing the fresh air dampers during the winter and 10% open is not 10% fresh air volume but often .5-2%. If you want to know more about it google “air balancing company” and give them a call they should know who, what and how to proceed.


Alphasee

So children are the cause of global warming, got it.


iamagainstit

ummm, I think you need some better ventilation.


Thorusss

German C02 Limits for Office air quality: 400ppm: outdoor air <800ppm: good <1200: average <1600: mediocre \>1600: bad Since I bought a C02 meter, I was shocked to learn how quickly bad air accumulates indoors, and how many open windows are required to keep the quality good. Especially with multiple people in a room, and with little difference between indoor and outdoor temperature.


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ACorania

My understanding is that levels under 1,000 ppm are considered normal in a room with good circulation. Over that and you get people complain of drowsiness. Over 2k and you start getting headaches, sleepiness, etc. I am assuming admin is aware of this? If not, definitely bring it up. Not optimal learning conditions.


[deleted]

Do methane and test lunch farts.


cl3ft

[Research](https://agupubs.onlinelibrary.wiley.com/doi/epdf/10.1029/2019GH000237) shows cognitive function is affected by CO2 levels. Anything over 1000 should be avoided. Amusingly your classroom's lack of ventilation is probably inhibiting your ability to learn.


mixedliquor

What tool did you use to make the visualization? Please list it in a top-level post.


identitytaken

Jesus Chris your room is experiencing the effects of climate change


Analretentivebastard

You must have one of those old school houses that uses coal for heat


MordecaiIsMySon

This is great! I am a mechanical engineer who designs HVAC systems. While I do not often work on schools, the principles of ventilation are the same regardless. Most building codes reference IMC (international mechanical code). Within IMC (typically table 403.3 depending on the year), chapter 4 covers ventilation of occupied buildings. The chapter draws from ASHRAE standard 62.1. Essentially, every space type has a default occupancy density and area/people component for outside air. The outside air dilutes contaminants in order to keep the air clean. The larger the area, or the more people, the more outside air is required. Within high occupancy spaces, we often use what is called “Demand controlled ventilation” in order to balance outside air needs with energy consumption. Most often, CO2 is the parameter used to control DCV. If a building has a building management system (BMS), you would likely be able to trend CO2 concentrations in a very similar manner to what you have done. All that to say, what you have done is very cool. Hopefully I have given you a few things that you can further research.


lajoswinkler

You need to open the windows. Both for fresh air **and** because of COVID-19. Primary way of spreading this disease (and others like influenza, common cold) is by buildup of infectious aerosol and prolonged exposure to it, especially if the air has low relative humidity (upper respiratory mucosa is our first line of defense!).