Developing methodology for testing of gas-phase air cleaners based on perceived air quality

The existing standards for testing gas-phase air cleaners are based on challenging them with gaseous substances. They do not describe air quality measurement using perception, and human emissions (bioeffluents) are not used as challenge pollutants. The present work examines the method that can be used as an alternative or together with other methods used for testing gas-phase air cleaners. The work is a part of the IEA's Annex 78. Three gas-phase air cleaners were tested in the Technical University of Denmark labs. Testing was conducted in rooms adapted for laboratory experiments ventilated with different outdoor air supply rates; emissions from typical building materials and people were used as challenge pollutants. The effects of using air cleaners were examined by rating the air quality's acceptability and odor intensity. For this purpose, participants (subjects) were recruited. The rating was made by entering the rooms or on the air extracted from the rooms; in both cases, the subjects were blind to exposure conditions. The air was sampled at the lowest ventilation rate for the subsequent GC/MS analysis. The results showed that air cleaners using activated carbon performed better than the ones using ion generators. The former improved perceived air quality when challenged with emissions from building materials but not when human emissions were present. The experience gained will allow for developing the standard for gas-phase air cleaners that can be compatible with the requirements for ventilation in the current standards based on sensory ratings and considering emissions from building materials and people.