This curriculum guide contains 18 units of instruction for a competency-based course in residential and light commercial heating, ventilating, and air conditioning (HVAC). Introductory materials include a competency profile and an instructional/task analysis that correlates job training with related information for this course. Each instructional unit includes some or all of these basic components: performance objectives; suggested activities for teachers and students; information sheets; assignment sheets; job sheets; visual aids; tests; and answer keys. Units are planned for more than one lesson or class period. A list of tools, equipment, and materials and an alphabetical list of 38 references are provided. Unit topics include: psychometrics for residential HVAC; residential load calculations; residential duct design and sizing; residential air treatment; psychrometrics for light commercial HVAC; load calculations for light commercial HVAC; light commercial system design; light commercial air treatment; standard gas-fired furnaces; high-efficiency gas-fired furnaces; oil-fired furnaces; electrical heating systems; cooling systems; heat pump systems; balance points; introduction to hydronics; customer relations; and service operations. (YLB)