Analysis of Crew Quarters � ECLSS Interactions for Improved Temperature Control and CO2 Mitigation



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50th International Conference on Environmental Systems


Crewmembers spend a substantial amount of time within their crew quarters (CQ) as a source of heat and CO2. Currently, CQs on-board the International Space Station (ISS) exchange air with the cabin aisle to provide a comfortable space, i.e. satisfactory temperature, humidity, and CO2 levels. However, limited temperature and CO2 concentration differences between the cabin and CQ necessitates high air exchange rates to achieve suitable CO2 washout and thermal control. Exploration spacecrafts may try to leverage the various air revitalization streams to improve upon the current configurations. Interaction between the Environmental Control and Life Support System (ECLSS) and the CQ have been analyzed to understand the effect on CO2 washout and thermal efficiencies. Both the direct delivery of conditioned air from the Temperature and Humidity Control (THC) and low CO2 air delivery from the Carbon Dioxide Removal Assembly (CDRA) have been studied. Independent delivery from these sources are inadequate to effectively control both temperature and CO2 levels below thresholds of 72.4 �F and 2 mm Hg, respectively. Conditioned THC air can control temperature with significantly lower air flow rates; however, poor CO2 washout leads to its accumulation. In contrast, CDRA air delivery can effectively lower CO2 concentrations which would reduce crewmember exposure to elevated CO2 levels; however, the hot CDRA air is poor at controlling temperature. A combination of both strategies, i.e. THC + CDRA air delivery, are able to provide crew comfort and reduce CO2 concentrations while significantly reducing air flow rates by ~75% even in the worst-case scenario (95th percentile crewmember and maximum CDRA air temperature). Additionally, this design implements a Nafion membrane prior to air delivery to pre-condition the CDRA air to provide a stable air temperature. This study illustrates the analysis of different ECLSS-CQ configurations and the trade-offs to utilizing different air revitalization streams.


Thomas Chen, ERC, inc
Michael Ewert, NASA
ICES305: Environmental and Thermal Control of Commercial and Exploration Spacecraft
The 50th International Conference on Environmental Systems was held virtually on 12 July 2021 through 14 July 2021.


ECLSS, Modeling, Crew Quarters, CDRA, THC, CO2 Removal, Thermal Control