Yes, this is a useful technique for surveying the ventilation in a lot of spaces, although it has some limitations that require careful consideration for your specific application.
Outdoor carbon dioxide (CO2) in our big cities is currently about 420 ppm, and human breath increases this concentration when you’re indoors.
In well ventilated spaces, CO2 should stay below about 800-950 ppm. In poorly ventilated spaces CO2 can reach levels of 3,000-5,000 ppm which is a very dangerous situation.
Surveying CO2 levels in school classrooms, gyms, bars, rideshare, and public buildings can be useful to get a general sense of which spaces may have the worst ventilation, and prioritizing actions there.
You can readily measure CO2 concentration continuously with an affordable wireless indoor air quality monitor and data logger. We recommend non-dispersive infrared (NDIR) sensing technology for accuracy. Contact us if you have any questions.