Checking of ventilation rates by CO2 monitoring.

Paper i proceeding, 1996

The present paper presents results from measurements of outdoor airflow rates and air change rates carried out simultaneously with measurements of the indoor concentration of carbon dioxide (CO2 ) . The measurements were made both under controlled laboratory conditions and in the field. The field experiments were performed in a conference room, an assembly hall and an office room, and the laboratory investigation was carried out in a 19 m³ test chamber. CO2 measurements can be successfully used to estimate the outdoor airflow rate in occupied rooms, but it is vital that the methodology takes into consideration a number of possible sources of errors. For example, it can not be presupposed that steady-state conditions prevail. However, inaccuracies due to non steady-state conditions may be reduced by a thorough analysis of the measurement results. Furthermore, it is demonstrated how the air change rate can be determined using a method based on analysis of the CO2- concentration decay in a room.