A070 Office neutral CO2

Evaluation of neutral criterion of indoor air quality for air-conditioned offices in subtropical climates

Brief:

Occupant-generated carbon dioxide (CO₂) is used as the tracer gas to determine ventilation rate. Although CO₂ concentration may not provide a comprehensive indication of indoor air quality (IAQ), it can be a good indicator of the concentration of other human bioeffluents perceived as a nuisance and be used to identify the acceptability of IAQ in a space by its occupants. In this study, the acceptability of IAQ in air-conditioned offices was evaluated by the subjective responses of the office occupants with respect to indoor CO₂ concentration. CO₂ concentrations at 396 sample locations were measured and subjective responses at those locations were recorded by an electronic questionnaire. Specifically, an occupant’s indirect acceptability of the perceived IAQ indicated on a semantic differential evaluation scale was correlated to the occupant’s direct acceptability described by a dichotomous scale. The overall acceptability of IAQ from all occupants was then described by a logistic regression model and shown to correlate with indoor CO₂ concentration.

Further information:

Mui KW, Wong LT, 2007. Evaluation of neutral criterion of indoor air quality for air-conditioned offices in subtropical climates, Building Services Engineering Research and Technology 28(1) 23-33.