Perceived air quality, Sick Building Syndrome (SBS) symptoms and productivity were studied in a normally furnished office space ventilated with an outdoor air flow of 3, 10 and 30 L/s per person (corresponding to aiur changes of 0.6, 2.0 and 6 h-1, respectively), while all other environmental parameters remained unchanged. Ventilation was provided by an axial fan mounted in the window to avoid any potential pollution sources in a traditional HVAC system, and almost perfect mixing of air was provided at an air velocity below 0.2 m/s in the occupied zone. At each ventilation rate, 30 female subjects occupied the office for 4.6 hours in the afternoon, six subjects at a time; they remained thermally neutral by adjusting their clothing. Subjects assessed perceived air quality and SBS symptoms, and performed simulated office work so that their productivity could be assessed. Increasing the supply of outdoor air reduced the percentage of people dissatisfied with the perceived air quality (P less than 0.002), the perceived stuffiness of air (P less than 0.05), and the perceived dryness of throat and mouth (P less than 0.0006), and eased difficulty in thinking clearly (P less than 0.001). The productivity of subjects improved monotonically with increasing ventilation rate, and for each twofold increase of ventilation rate the overall performance of subjects improved on average by 1.4%. The results of this study confirm the benefits of proper ventilation of indoor environments.
|Title of host publication||Proceedings of DKV-Jahrestagung|
|Place of Publication||Berlin|
|Publication status||Published - 1999|