(2021-02-17) How To Quantify The Ventilation Rate Of An Indoor Space Using A Cheap Co2 Monitor

How to quantify the ventilation rate of an indoor space using a cheap CO2 monitor. The ventilation rate can change enormously between different spaces, and these changes are very important.

determining a realistic ventilation rate for a space can be difficult.

I have bought and tested a $159 CO2 monitor (Aranet4) (US, see this link for Europe), recommended by our European colleagues at REHVA, and it seems to work well (see Appendices 1 and 2 at the bottom for results of different tests).

Look for NDIR technology

take good notes of what you did whe

(1) Leave the CO2 monitor outside for at least 5 minutes to record the background concentration

(2) Stay in the location of interest

let the analyzer record CO2 for several hours.

this method will only quantify the ventilation rate with outdoor air. In many spaces, air is recirculated and filtered, and many virus-containing aerosols will be removed by the filter. But CO2 will be unaffected by the filters