Streamlining IAQ guidelines and investigating the effect of door opening/closing on concentrations of VOCs, formaldehyde, and NO2 in office buildings

Abstract

Indoor air quality (IAQ) 'standards' and 'guidelines' were established by international organizations to reduce harmful concentrations to an acceptable minimum to protect building occupants from detrimental health effects. Three major pollutants are commonly found in the indoor environment; these are volatile organic compounds (VOCs), formaldehyde (CH2O), and nitrogen dioxide (NO2). The objective of this study is two folds: first, guidance is presented for selecting the proper 'standards' and 'guidelines' when investigating IAQ problems. Second, an investigation is carried out to determine the effect of door opening and closing on the concentrations of VOCs, CH2O, and NO2 in office buildings in Kuwait during three wave periods (pre-, post-, summer) at three temperature settings (17 °C, 26 °C, AC shutdown). A modern office building in Kuwait was selected for the study. T-tests revealed significantly higher concentrations (p = 0.027, 0.018, 0.002 for VOCs, CH2O, NO2, respectively) of all three pollutants when doors were closed. All unstandardized B coefficients for the three pollutants were significantly higher when the doors were closed in comparison to open doors. B coefficients showed no significant association between wave periods, temperature settings, and pollutant concentrations; a finding that can be helpful in setting the air conditioning temperatures toward the higher end of 26 °C for energy savings. Two-way ANOVA test for VOCs showed no interaction effects between door openings and wave periods or temperature setting, indicating that VOC concentrations during the wave periods and temperature settings were not affected by the door opening.