Letter from America.


Simulation of CO2 concentration for determining air change rate.

The CO2-concentration of room air provides an indicator for the air quality in spaces without smokers. A classroom with mechanical ventilation has been evaluated for eighteen months using such a technique. These measurements were made within the framework of the research project Gumpenwiessen. A model to calculate the CO2 concentration as a function of occupancy, activity level of the occupants and air change rate was developed. It was validated using the measurements data.

Ventilation efficiency - Part 2.