Based on the Air Conditioning Institute Curriculum Guide, this text provides theoretical and practical information to supplement and advance skills of the entry-level student and technician. It focuses on air conditioning systems and the components that make up these systems, while emphasizing information that will be useful to the service technician. The material presented here stresses the competency-based educational approach, preparing students to exhibit learned skills in several different ways, and put information into practice so that it is useful and maintained.