Investigation of Airflow and Accumulation of Carbon Dioxide in the Service Module Crew Quarters 2002-01-2341

Accumulation and re-breathing of CO₂ in expired air has been investigated as a possible indication for crew discomfort onboard the International Space Station (ISS) Service Module crew quarters. In addition, inadequate airflow contributes to increasing temperature that also leads to crew discomfort. The objective of this study is to evaluate possible medical hazards that can occur when a crewmember is sleeping in the crew quarter of the ISS Service without proper ventilation. This paper investigates a projected increase in CO₂ in the enclosure under a no ventilation scenario. A Computational Fluid Dynamics (CFD) model of the crew quarters and of a human body are built to investigate the ventilation profile and the CO₂ concentration inside the volume of the crew quarters. Respiratory characteristics of a typical 180-pound crewmember are simulated. The results for the distribution and concentration of expired air at different time intervals and at different locations are presented. Finally, a protocol for the ISS crew quarters in the event of insufficient ventilation or no airflow is suggested.