This student guide, one of a series of correspondence training courses designed to improve the job performance of members of the Marine Corps, deals with the skills needed by air conditioning mechanics. Addressed in the four chapters, or lessons, of the manual are the following topics: principles of air conditioning, refrigeration components as applied to air conditioning equipment, procedures for servicing air conditioning equipment, and commercial and tactical air conditioning units. In a seperate section following chapter 4 are 4 review units corresponding to the 4 lessons in the guide. Each unit contains a reading assignment, a lesson objective statement, and a written assignment consisting of a series of study questions for that unit. (MN)