A personal air distribution system with air terminals embedded in chair armrests on commercial airplanes

A mixing air distribution system is currently used on airplanes, which supplies cool air at high momentum from the ceiling level and extracts the contaminated air at the deck level. However, such highly mixing context has led to numerous complaints not just for air quality but also for thermal comfort. To improve aircraft cabin environment, this investigation has proposed a personal chair-armrest-embedded air system. The system delivers conditioned, outside air directly to the breathing zone of a passenger from the air terminal devices embedded within both chair armrests. While simultaneously, a part of outside air mixed together with most of the recirculated air is supplied from the perforated under-aisle panels, and the contaminated air is extracted through the overhead exhausts on the ceiling. To assure thermal comfort, the personal air is conditioned to 25 C in relative humidity of either 15% or 30%, so the cabin is mainly cooled down by the air supplied from the under-aisle panels. After elaborate investigation with experimental test and computational fluid dynamics (CFD) modeling, this study finds that by combining the under-aisle air supply with the personal air supply at the chair armrests, the system is robust to prevent the contaminants released at any height to the passenger's breathing region. Though there is vertical temperature stratification, the system is acceptable in perspective of percent dissatisfied due to draught risk. To aid for personal air system design, some optimal basic parameters are recommended. (C) 2011 Elsevier Ltd. All rights reserved.