A field study investigated outside air delivery and thermal comfort in a normally operating variable-air-volume (VA V) system. In addition to finding that outside air delivery and thermal comfort are generally acceptable under a variety of operating conditions, a number of practical diagnostic techniques were used to more fully understand VA V system operation and design. It was concluded that unless a VAV system is well understood or continuously monitored, the likelihood of unexpected system behavior that can impact the outside air delivery and thermal comfort is high.

Variable-air-volume systems utilize some of the latest technology available to control zone temperatures and save fan energy. In fact, the energy savings can be quite substantial. Then why do engineers and building managers have reservations about using this type of system? Probably the memory of past experiences. The chain of design, equipment selection, installation, and air balancing must be tailored to a building’s needs or conflicts will arise. There are many disciplines to consider when creating a VAV system, and if one link is weak, there can be trouble.

Over 90% of office workers would rather be served by natural ventilation systems, so why is it not normal practice?
Many architects and consultants argue that serious technical difficulties make it impossible to implement.