Book excerpt: The Esco Institute Quick Guide to the Refrigeration Cycle, Refrigerants, and Components is intended to provide industry personnel with a review/refresher of fundamental concepts needed to be successful on the EPA Section 608 examination. This book will provide an overview of the following: -concepts and measurements of pressure as well as the related gas laws. -temperature/pressure relationship as it relates to the refrigeration cycle. -study of thermodynamics and heat transfer. -the refrigerant cycle, refrigerant states, and temperature/pressure relationships. -refrigerant composition, properties, and refrigerant applications. -common oils used with refrigerants, their applications and uses, and safe handling. -the process of retrofitting a system to use an alternative refrigerant and oil as well as system cleanup. -the function and applications of evaporators, condensers, compressors, and metering devices. -typical operating conditions for system components under normal conditions. -proper installation and maintenance of the refrigerant circuit components.