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. The daily profile of CO2 concentration and the duration of time when the limit of 1500ppm is exceeded can be predicted. The prediction can be made for any time step and any room. The model is useful as a planning tool for fixing the necessary air change rates for occupied rooms.