Personalized ventilation solutions for reducing CO2 levels in the crew quarters of the International Space Station

The present paper studies the possibility of personalized ventilation (PV) systems to improve air quality in the breathing zone of astronauts resting in the crew quarters aboard the International Space Station. In the absence of gravity CO2 accumulates in pockets near the astronaut's head, potentially leading to symptoms of CO2 intoxication. The addition of a PV system aimed at an astronaut's breathing zone during sleep could provide a supply of fresh air directly to the face and reduce the risks of intoxication. Experimental measurements of the PV diffuser velocity fields were performed in an experimental setup and the results were used to validate the numerical solution for the PV case connected to the already existing general ventilation system of the crew quarters. CFD models were used in order to reproduce the conditions of microgravity. Two PV configurations were studied, the first with the PV diffuser position in front of the human occupant and the second was positioned laterally, both being aimed at the breathing zone. The results were compared to a case without PV. Results indicate that the lateral PV solution is more viable than the frontal solution providing a reduction in overall CO2 levels in the breathing zone. The lateral PV also leads to an 8% reduction in the volume of CO2 inhaled over the course of each breath having the potential to improve air quality over longer periods of time.

Automated summary

This study examines the use of personalized ventilation (PV) systems on the International Space Station to enhance air quality for astronauts resting in the crew quarters. Experimental measurements and numerical simulations suggest that a lateral PV solution is more effective in reducing CO2 levels in the breathing zone, potentially improving air quality over extended periods of time.