What type of equipment do you use?
Variable Frequency Drives (VFDs)
Many variable air volume fans operate at constant speed over the system’s entire operating flow range. The fan flow is controlled by opening and closing dampers to provide cooled air to the conditioned spaces. A significant amount of energy is wasted when the system is operating at low cooling loads. A variable frequency drive (VFD) can be used to vary the speed of the motor, thus allowing the fan to match its output to the fluctuating system load. A study conducted by Commonwealth Edison Company, in which inlet guide vanes equipping 200 hp supply and 50 hp return fans were replaced with a VFD, found that the VFD provided average energy savings of 48 percent. In this case, the result: annual energy savings of $15,734.Show More Info
Consider Variable Speed Drives on Pumps and Fans
Pump and fan capacities can be reduced and energy saved by using variable speed drives to control their speed. However, don’t forget to consider taking low-cost measures to reduce capacity, especially where the pump or fan is running at constant speed most of the time. For instance, if a fan is driven by V-belts, its capacity can be changed by altering the size of the drive pulleys. Similarly, a pump’s capacity can be changed by trimming its impeller. These are low-cost alternatives to expensive electric drive modifications. Reductions in both peak and off-peak energy costs can be obtained by using variable speed drives on pumps, fans and compressors that operate at varying loads. The use of these drives will have little impact on demand because they will require the same kilowatts at peak-demand periods as fixed speed drives. They pay off better if the systems they are applied to operate at part load for relatively long hours.
Use variable speed drives on pumps, fans, and compressors operating at varying loads
To reduce both peak and off-peak energy costs, use variable speed drives on pumps, fans, and compressors operating at varying loads. The use of these drives has little impact on demand because variable speed drives require the same kilowatts during peak-demand periods as fixed speed drives.