This guide provides job relevant tasks, performance objectives, performance guides, resources, learning activitites, evaluation standards, and achievement testing in the occupation of environmental control system installer/servicer (residential air conditioning mechanic). It is designed to be used with any chosen teaching method. The course outline is divided into six duties: (1) brazing, cutting, fitting, soldering, and welding piping and tubing; (2) installing and servicing controls; (3) installing and servicing electrical circuits, components, and motors; (4) installing and servicing compressors, condensers, evaporators, and water towers; (5) installing and servicing refrigeration systems and domestic refrigerators; and (6) installing and servicing residential air conditioning and heating systems. A total of 154 performance objectives are categorized under these duties. The performance objective is defined in terms of task, conditions, standard, and source for standard. These components are provided for each performance objective: performance guide, enabling objectives(s), learning activities, resources, and evaluation (questions and answers). Appendixes include a cross-referenced table of duties, tasks, and performance objectives; tool and equipment list; sources of standards; state-of-the-art literature; a bibliography; and written evaluation questions and answers. (YLB)