OCCUPANT-GENERATED CO2 AS AN INDICATOR OF VENTILATION RATE

Abstract

Ventilation rate.s in buildings are generally determined by means of tracer-gas techniques that permit calculation of the nur.1ber of air changes per hour occur in a given area, or, alternatively, by measuring the actual air flow in the ventHation ducts.There are <Uf~ ficulties associated with both of these methods.In this study in a San Francisco office building, we used occupant-generated co 2 as an indicator of the actual ventilation rate.Two techniques were employed, a decay method and an integral method and, in both cases, measurements were conducted si.multaneously at several locations.The decay method compared favorably \Jith the conventional measurement methods in both the all-outside-air and recirculation modes, whereas the al method showed a considerable deviation from the other methods in the recirculation mode.Both.techniques shol:l promise of being sui table methods for measuring ventilation rate in commercial or institutional buildings.