~420 ppm
CO₂ level of outdoor air today. Indoor levels start from this baseline.
NOAA Global Monitoring Laboratory
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Classroom CO₂ monitors: what the data says about ventilation
Classroom CO₂ monitors went up in many schools in recent years. Most of the data they store is never looked at. I analyze weeks of readings from your classrooms and show you which rooms struggle and which ventilation routine actually works.
Why classroom CO₂ rises so fast
Classroom CO₂ rises faster than in most offices. You have 25 or more students in one room for hours. In winter, windows stay closed. Many older buildings have limited mechanical ventilation.
Teachers see the monitor turn red. They don't have time to compare charts across rooms. Yet the stored data answers the key questions. Does airing out between periods work? How fast does CO₂ climb back? Which rooms can't keep up, no matter what?
700 ppm
Above outdoor air is a widely used ventilation benchmark. In a classroom, that means roughly 1,100 ppm.
ASHRAE Standard 62.1 guidance
5 ACH
CDC suggests aiming for 5 or more air changes per hour of clean air.
CDC, Ventilation in Buildings (2023)
How I analyze classroom CO₂ data
Export the data
Most CO₂ monitors store readings and export a file. If you're not sure how yours works, I'll help. Then you upload everything through a secure link.
Compare rooms against the bell schedule
I line up every room with the class schedule. You see where CO₂ peaks, where airing out between periods helps, and how fast each room clears.
Get a ventilation routine
Within 1–2 weeks you get a report your principal, district, and parents can follow. It includes a simple routine per room and a list of rooms that need more than open windows.
Thought about it but never got around to it? Getting started takes two minutes.
- 01
Tell me what's going on
Use the inquiry form to tell me which room it is and what bothers you. It takes two minutes.
- 02
Send data or start measuring
If you already have a monitor, send me the export through a secure upload link. If not, I'll tell you which device is enough and where to put it.
- 03
Get your answer
Within one to two weeks, you get a short report: what's going on, why, and what to do first. No site visit needed.
Questions
Do we need new monitors?
Usually not. Your existing monitors are often enough if they log data. If not, I help you plan what to use and where.
Do you collect data on students?
No. I only get CO₂ readings with timestamps and the class schedule. No names, no personal data.
Who usually orders this?
Principals, district facility teams, daycare directors, or parent groups. You get a clear quote first, and the scope depends on the number of rooms.
Can you analyze just one classroom?
Yes. One problem room is a good place to start. The results often show if other rooms need a closer look.