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

Abstract

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.

An Approach Towards Development Of Pmv Based Thermal Comfort Smart Sensor

“…In real cases indoor air can be up to 10 times more polluted than outdoor air [13,14]. Although healthy people can tolerate CO 2 level up to 10,000 ppm without serious health effects [15] and a tolerable level of CO 2 should be kept below 1000 ppm [16]. CO levels in laboratory without gas stoves vary from 0.5 to 5 ppm.…”

Indoor Environmental Quality Benchmarks for Air-conditioned Offices in the Subtropics

“…Indoor environment conditions such as air temperature, relative humidity (RH), and carbon dioxide (CO 2 ) concentrations were specified for labeling air-conditioned offices as having 'Good' and 'Excellent' indoor environmental quality (IEQ) [2]. systems undergoing economic operations could not sufficiently address the collective expectations of occupants on IEQ [3,4]. Apart from liquidated devaluation and probable detraction of property image, poor IEQ would also degrade the indoor air quality [5].…”

Using Carbon Dioxide Concentration to Assess Indoor Air Quality in Offices

“…In a typical air-conditioned indoor environment, carbon dioxide (CO 2 ) concentration could be selected as a surrogate indicator for assessing the IAQ [10][11][12][13][14]. Monitoring of CO 2 concentrations allows us to estimate the occupants' comfort in a space and how well the installed ventilation system is operating.…”

“…Monitoring of CO 2 concentrations allows us to estimate the occupants' comfort in a space and how well the installed ventilation system is operating. A number of relationships were suggested between indoor CO 2 concentration and IAQ, such as the health effects of elevated CO 2 concentrations, the impact of CO 2 concentration on the occupants' perceptions of an indoor environment, the relationship between CO 2 concentrations and other contaminants, and the association between CO 2 and outdoor air ventilation rate [10][11][12][13][14][15][16].…”