Variable Air Volume Boxes are compact and design and easy to install. The Boxes are of pressure independent type, complete with a microprocessor DDC controller, damper, damper actuator, cross flow velocity sensor with differential pressure transmitter, thermostat and in-built step down transformer. The Boxes comprise of a micro processor based BAC net MS/ TP DDC controllers, and enable interface for the communication with the third party BAC net based BMS systems. The Variable Air Volume Boxes are capable of providing efficient performance.