In the First Edition of this classic text, Roger Haines devised a simple building-block method which enabled students to quickly learn about the operating principles and applications of all the basic devices and subsystems used in HVAC control. The new Fifth Edition, completely revised by Douglas Hittle, takes into account the many technological changes that have arisen since then. Crystal-clear guidelines on combining control devices, circuits, computers, and HVAC equipment into efficient control systems that are accurate and energy-efficient are presented along with hundreds of charts and illustrations which provide data critical to the understanding and design of modern HVAC systems. These include: psychrometric charts and tables relating to optimal levels of temperature and humidity at specific altitudes: block/flow diagrams which show control component function; circuit diagrams of important electrical control system components; schematic diagrams showing the configuration of various control systems.