This Honeywell Variable Air Volume (VAV) Controller Excel is a microprocessor-based controller designed for commercial HVAC control applications. The device operates on a 24 Vac power supply and communicates with the building automation system via a C-Bus network. It features an inbuilt actuator, temperature sensor, and pressure transducer to regulate air flow in response to room or duct temperatures. The controller also includes software algorithms for single-duct, dual-duct, fan-powered, and supply/exhaust VAV box control applications. It has a compact size of 4-7/8 x 4-1/2 x 2-9/16 inches and weighs approximately 1.5 pounds.