Some guidelines on indoor-air quality specify a maximum allowable exposure to CO2. In a room ventilated by a mechanical extract system a control program on the CO2 concentration may, by anappropriate sampling strategy, supply information about the exhausted flowrate. This paper briefly outlines a simple analytical model for estimating the exhausted flowrate by measuring the CO2 concentration and keeping a record of the occupancy of the room.
This article presents a number of examples of how the supply of outdoor air to a room can be adapted on the basis of the measured content of carbon dioxide in the indoor air, so that an acceptable air quality will be maintained in the room. The results of studies carried out in a conference room , three offices and a school are reported. The measured values of carbon dioxide contents were employed both for controlling the outdoor air flow and for checking that the ventilation systems operate satisfactorily.