Impact of temperature and humidity on perception of indoor air quality during immediate and longer whole-body exposures

Acceptability of clean air and air polluted by building materials was studi ed in climate chambers with different levels of air temperature and humidit y in the ranges 18-28 degrees C and 30-70% relative humidity (RH). The acce ptability of the air quality immediately after entering a chamber and durin g the following 20-min whole-body exposure was assessed by 36 untrained sub jects who maintained thermal neutrality by modifying their clothing. The re sults confirm the significant decrement of the acceptability with increasin g temperature and humidity, as shown in a previous study with facial exposu res. The odour intensity was found to be independent of temperature and hum idity. A linear relation between acceptability and enthalpy of air was agai n observed by this experiment. No significant difference was observed betwe en the immediate acceptability and the acceptability during the following 2 0-min exposure, i.e., no adaptation took place. Both the immediate assessme nt of acceptability and the assessments during the 20-min exposure were ind ependent of the air temperature and humidity to which the subjects were exp osed before entering the chamber. The results further indicate that a notab le decrement of the ventilation requirement may be achieved by maintaining a moderate enthalpy of air in spaces.