This self-study course is designed to familiarize Marine enlisted personnel with the principles of the refrigeration process. The course contains five study units. Each study unit begins with a general objective, which is a statement of what the student should learn from the unit. The study units are divided into numbered work units, each presenting one or more specific objectives. Text is furnished, illustrated as needed, for each work unit. At the end of the work units are study questions, with answers listed at the end of the study unit. A review lesson completes the course. The five units of the course cover the following subjects: fundamentals of refrigeration, refrigerants and lubricants, refrigeration systems and components, refrigeration controls, and air conditioning. (KC)