This document provides an overview of air conditioning systems, including: 1. It classifies air conditioning systems as either unitary systems (window units, split units, package units) or central systems, and also classifies them based on the season (winter, summer, year-round). 2. Unitary systems are factory assembled while central systems are assembled on-site, and it describes the equipment that makes up each type of system. 3. When selecting a system, factors like customer objectives, economics, occupancy, and thermal load must be considered. 4. Air conditioning systems are also grouped into direct expansion, all-water, all-air, and air-water systems, and it provides