CO2 meter


Senior Member
Baltimore, MD
I bought an Aranet4 CO2 meter to test air freshness on an upcoming train trip. The meter is used as a proxy for COVID contamination; an air exchange rate giving readings under 800 is best.

The literature says that over 1000 CO2 ppm, people start having cognitive problems. I tested the 2 places I spend most of my time - my bed, and a couch tucked against the wall. Both areas tested over 1000. This was very easy to fix by cracking the windows open. I did discover that just running a good fan didn't help.

I can't say that my brain is working normally, but I am all-around sharper, and I can do more before my brain starts hurting.