Carbon dioxide measurement as a means of ventilation control

Notes the considerable savings in heating energy that could be made if ventilation rates could be modulated so that only the requirements of the actual number of occupants was supplied. Explains how this can be done by ventilating to maintain a constant concentration of carbon dioxide. Describes carbon dioxide monitoring system based on infrared absorptiometry. Illustrates diagrammatically the layout of a cinema ventilation system which monitors carbon dioxide levels and explains its operation. Notes other buildings where the system is used. Notes its additional application to the control of direct gas fired heating units, with up to 30% savings.