Variable Frequency Drives
A VFD is a device that matches the energy the motor needs with the work that is being done. Installing a VFD on an AHU fan allows the VFD to vary the speed of the fan. As the fan slows down, it draws less power than at constant speed, resulting in energy savings.
Many AHU system are engineered for 100% design flow, but many could operate with less flow. For example, fans that are turned down just 10% can save up to 25% in energy costs. In most systems, reducing the speed by 50% can cause a 75% drop in energy consumption.