An indirect method for measuring ventilation rates.

Describes a method for determining the rate of air change in a ventilated space using carbon monoxide as a tracer gas. Concentration of carbon monoxide was found by an infra-red analyser which proved to be very precise and sensitive and made it possible to carry out analyses in a short time. Air change rates were measured in a laboratory with open windows and with closed windows. Concludes that air change rates are greater with few large openings than with many small ones.