This book provides an in-depth review of the design, performance and control of variable air volume (VAV) systems. Since they were first developed in the US more than 30 years ago, VAV systems have been widely used in multi-zone air-conditioning applications throughout the world. The system remains one of the principal tools for the HVAC designer addressing commercial applications of medium to large scale. While the book concentrates on single-duct throttling VAV systems, all principal types of VAV systems are discussed, including fan-assisted terminal units and dual-duct VAV. It examines in detail the characteristics, design and engineering of VAV, and also includes comparisons of capital and running costs, energy use and the various alternatives available to the system designer. The book brings together, in a single volume, a wealth of information not otherwise available to the busy, practising HVAC engineer, and will also interest specialist researchers and students of building-services engineering.