Describes the monitoring of indoor air quality in a San Francisco office building where occupants had registered eye, nose and throat irritation complaints. Data was taken under two different ventilation rates. Carbon dioxide concentrations increased as the ventilation rate decreased, odour perceptibility increased slightly at the lowest ventilation rate, and other pollutants generally showed very low concentrations, which increased when ventilation was reduced.
Many mechanically ventilated buildings are over-ventilated since ventilation rates are based on a fixed number of people (often in excess of the average occupancy) and no allowance is made for infiltration. States that the CO2 concentration in the ventilated space can be related to the ventilation rate per person, and by modulating the fresh air flow to maintain a constant CO2 concentration, a constant ventilation rate per person can be obtained.
Reviews important sources of indoor air pollutants, and discusses ways of measuring the contaminants emitted by the presence of man in a room. In a test chamber the carbon-dioxide and the odour intensity were measured as a function of room occupancy and ventilation rate. When the supply of fresh air was12-15m*3 per person per hour, the CO2 concentration was less then 0.15% and the odour intensity was evaluated only as a `slight annoyance'. Higher ventilation rates are necessary if increased physical activities and smoking is done in the rooms.
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