The International Space Station (ISS) Temperature and Humidity Control/Intermodule Ventilation (THC/IMV) system for the U.S. Lab provides required cooling air for the U.S. Lab and also provides “parasitic” cooling air for Node 1 and its attached elements. This scheme provides cooled air from the Lab THC directly to Node 1 and also to elements attached to Node 1, at different stages of Space Station assembly.A development test of the U.S. Lab and Node 1/attached elements' integrated THC/IMV ducting system was performed in the summer of 1995. This test included the U.S. Lab's development level Common Cabin Air Assembly (CCAA), which removes sensible and latent heat from the circulated and ducted cabin air. A referenced 1996 ICES Paper contains the initial correlation results.An analytical model has been developed, which has been used to predict flow and pressure drop performance of the system for several potential and actual changes from the Development Test configuration. Flight configuration versions of the model have been prepared. This paper presents further correlations of test data beyond those presented in the 1996 ICES paper, and predictions of flight performance incorporating changes in hardware and changes in operating conditions.The Development Test results and further analytic evaluations have revealed that there is a need for more cooling air flow to the Cupola than was provided by the tested development THC/IMV system. It has been determined that by isolating the port and starboard THC supply air duct strings from each other and operating both CCAA's, this deficit in cooling air for the Cupola can be overcome.