A VAV air system is an air distribution system that efficiently and effectively conditions outside and cools the spaces within a building.
It is an economical system because it operates right around the levels of the cooling loads. Since there are thermostats controlling each individual space, the amount of air being supplied to each room is continuously adjusted based upon the current cooling conditions.
This allows the system to be as efficient as possible.
The addition of an energy recovery wheel also helps to increase the overall efficiency and economy of the VAV system.
If used in a year round cooling situation, a variable air volume system is an effective way to keep a building comfortable.