Anyone know if there is a decent and affordable test kit for bedroom or small office?
It works well.
PM2.5/ HCHO/TVOC CO2
I have this exact model and it works very well. I keep my apartment window openly constantly whenever I'm home now (though my place is pretty small).
I live in a 60m2 cheap apartment and if I keep the place closed, CO2 levels will exceed 800ppm in about two hours just from one person breathing.