Transmitter Signals Precise Air Velocity Adjustments to Computer-Controlled Variable-Speed Fan Motor

In variable air volume (VAV) HVAC systems, a computerized control provides precise adjustment of air volume to meet changing system needs with maximum energy efficiency. The Series 641 has an optional LED display for local indication of air flow. The LED display provides a quick, visual acknowledgement of proper system performance. The computer reacts to any change in velocity by signaling the motor control to increase or decrease fan speed to maintain the required velocity. The computer, taking inputs from other ambient condition sensors, will establish a new required air velocity and signal an appropriate adjustment in fan speed.