Quantification of the association of ventilation rates with sick building syndrome symptoms

Abstract

SUMMARYData from published studies were combined and analyzed to develop best-fit equations and curves quantifying the change in sick building syndrome (SBS) symptom prevalence with ventilation rate. For each study, slopes were calculated, representing the fractional change in SBS symptom prevalence per unit change in ventilation rate per person. Values of ventilation rate, associated with each value of slope, were also calculated. Linear regression equations were fit to the resulting data points, after weighting by study size. Integration of the slopeventilation rate equations yielded curves of relative SBS symptom prevalence versus ventilation rate. Based on these analyses, relative SBS symptom prevalence increases approximately 23% (12% to 32%) as the ventilation rate drops from 10 to 5 L/s-person and relative prevalence decreases approximately 29% (15% to 42%) as ventilation rate increases from 10 to 25 L/s-person. KEYWORDS Association, Health, Quantification, Sick building syndrome, Symptoms, Ventilation rate INTRODUCTIONNumerous experimental and cross-sectional studies have investigated the associations of the prevalence rates of sick building syndrome (SBS) symptoms with office building ventilation rates. Studies have typically used the odds ratio or relative risk to indicate strength of the association of SBS symptom prevalence with ventilation rates and have generally controlled via the study design or analysis method for several potential confounding factors. Although ventilation rates, SBS symptom types, and findings have varied among studies, most studies have found that occupants of office buildings with lower rates of ventilation (outdoor air supply) per person have statistically significantly higher prevalence rates of SBS symptoms (Seppanen et al. 1999;Wargocki et al. 2002). For this paper, we have analyzed data to develop best-fit equations quantifying the change in relative SBS symptom prevalence with ventilation rate. A prior similar analysis quantified the relationship of relative work performance with ventilation rate (Seppanen et al. 2006). By quantifying these and other relationships between IAQ factors and health or performance outcomes, we seek to provide tools that better inform decisions about building design or operation.

Potted plants do not improve indoor air quality: a review and analysis of reported VOC removal efficiencies

“…To reduce VOCs and other indoor-sourced pollutants from the indoor environment, buildings traditionally make use of infiltration and natural or mechanical ventilation air exchange [29], which is the replacement of stale indoor air with fresh air from the outdoors. Higher ventilation rates have been correlated with lower absenteeism and SBS symptom incidences, reductions in perceptions of odors, and increased task performance [30][31][32][33][34][35]. However, increased ventilation may augment the indoor concentration of outdoor-sourced pollutants, such as ozone and PM [9,10,[36][37][38].…”

Impact of natural versus mechanical ventilation on simulated indoor air quality and energy consumption in offices in fourteen U.S. cities

“…Ventilation is the intentional exchange of outdoor air with the indoor air, and conditioning ventilation air to the appropriate thermal state can potentially amount to about half of building space-conditioning energy [4]. Ventilation rates may be increased or optimized [5] to enhance occupant productivity [6,7], reduce sick building syndrome [8][9][10] absenteeism [10,11], and generally to maintain acceptable indoor air quality [13].…”