This paper reports on a portion of the research sponsored by the ASHRAE Task Group on Energy Requirements (RP-66-0S), designed to field verify calculation methodologies for determining the energy requirements of buildings based on studies at The Ohio State University. Other sub-systems and the total sYptems are described in companion papers.The purpose of this study is to computer simulate the refrigeration subsystem (of a building's environmental control system) by modeling the system components and controls. Manufacturers performance data and the algorithms recommended in Ref 1 were used where possible. The simulation is carried out on an hour-by-hour steady-state basis. Field measurements made to verify the simulated results are collected on an hourly average basis. The preliminary results for this system were presented previously in Ref 6.