Impact of different ventilation strategies on aircraft cabin air quality and passengers’ comfort and wellbeing - the ComAir study

Indoor air quality can affect occupants in numerous ways. Especially carbon dioxide (CO2) and volatile organic compounds (VOCs) have been debated in their effects on health, well-being, and cognition of people. Aircraft cabins present indoor environments with distinctive features, where passengers are exposed to a mixture of outside and recirculated air. They include conditions such as high occupant density, inability to leave the environment, low relative humidity and need for pressurization. The ComAir study, funded by the Clean Sky 2 Initiative of the European Union, aims to investigate the impact of reducing outdoorair intake in the total volume of air supplied on cabin air quality and passengers’ wellbeing. The main experiment of the study uses a 2 (‘occupancy’) X 4 (‘air ventilation regime’) factorial design with stratified randomization of participants. Occupancy denotes the number of people in the aircraft (half vs. full) and varies the psychological important wellbeing factor of proxemics. The four air ventilation regime levels are: Baseline with typical aircraft airflows regimes per person, ASHRAE 161 requirement (standard recommendation), ASHRAE 161 half (half of the recommended flow), and a recirculation regime with a target CO2 concentration close to regulatory limit. This paper presents the background and experimental procedure of ComAir and gives some preliminary results on environmental conditions and subjects’ wellbeing and health under the baseline air ventilation regime.