The results of a preliminary evaluation of the heat loads for the Space Station Freedom U.S. Laboratory and Habitation modules are presented. The data for this analysis was based on a rack-by-rack assessment of preliminary module configurations. Data gathered included cooling requirements, temperature range, duty cycle and cooling split between liquid and air coolants for representative subsystem. and experiment heat loads. A Monte Carlo analysis of the heat load data was performed. The analysis results allowed initial sizing of the module cabin air, avionics air, and liquid cooling systems. The analysis allowed assessment of the effects of additional experiment automation as well as the effects of decreased avionics air cooling capacity.Although the heat load data and module configuration are preliminary in nature and will undergo significant revision as the Space Station Freedom design progresses, the results of this analysis provide a first look at the module energy flow.