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Few Caveats on Carbon Dioxide Monitoring.

pdf icon Few Caveats on Carbon Dioxide Monitoring. (211 K)
Persily, A. K.

IAQ Journal, Vol. 4, No. 1, 22-25, Summer 1994.


carbon dioxide; indoor air quality; tracer gas; ventilation; occupants


While techniques exist to relate indoor carbon dioxide concentrations to building ventilation and indoor air quality, they are not as simple as sometimes suggested. Some of the techniques can yield reliable results when used correctly, while others can result in serious errors. Using any of these approaches requires that one understands the technique and the following factors are considered: the outdoor carbon dioxide concentration; the number of people in the building and the rate at which they generate carbon dioxide; variations in the number of occupants within the building and over time; variations in the carbon dioxide concentration within the building; the measurement uncertainty of the carbon dioxide monitor being used; ventilation system operation prior to and during the measurements; and, indoor sources of carbon dioxide other than the occupants.