An instructor's manual and student activity guide on air conditioning, refrigeration, and heating units are provided in this set of prevocational education materials which focuses on the vocational area of trade and industry. (This set of materials is one of ninety-two prevocational education sets arranged around a cluster of seven vocational offerings: agriculture, home economics, distributive education, health occupations, world of work, trade and industry, and office occupations.) The instructor's guide is organized into the following elements: title of activity, duration of activity (four to ten periods), activity goals, eight instructional objectives, related vocational clusters, and activity implementation (description, safety precautions, materials needed, teacher preparation prior to class, during the class, follow-up activities, answer key to student check point activities and masters for duplication). The student activity guide is organized into three units: thermostats, warm air blower, and wall heaters. Step-by-step instructions (narrative and illustrations) for completing each instructional objective are provided. At the end of each set of instructions is a student check point (evaluation activity). Occupational descriptions for a hot air furnace installer and repairer, heat-transfer technician conclude the document. (JH)