System Aspects for Humidity Removal under Zero Gravity

The Columbus Orbital Facility (COLUMBUS) is the main European contribution to the ISS. Its Temperature and Humidity Control (THC) subsystem consists of the Condensing Heat Exchanger and Filter Assembly (CHXFA), the Condensate Water Separator Assembly (CWSA) and the Cabin Temperature Control Unit (CTCU).

The paper provides a description of the THC subsystem and its equipment focusing on the humidity removal function which has shown to be the major design challenge. Design solutions have been realised by optimising all equipment of the THC with respect to its system needs.

Test results both on equipment and on THC subsystem level are presented demonstrating that the humidity removal performance is adequate to meet the system requirements in the wide operational range of COLUMBUS.