Lyons et al. (1990) describes the use of VAV systems.
Most laboratories today consider VAV with reheat. This has been made possible by the development of economical and reliable hood controls and the ability to accurately track the quantity of supply and exhaust air locally in order to main constant pressure relationships.
Many terminal devices are available today. Essentially, each hood or group of hoods controls its respective VAV box. A matching supply box or boxes, depending on air quantities, is provided, with controls to permit tracking.
Operating diversities of 70 to 85% are possible.