Appliances
Install VFDs or Outside-air Economizers on Freezers/Refrigerators
What Is It?
A variable-frequency drive (VFD) is a device that controls the rotation speed of an alternating current (AC) electric motor by modulating the frequency of the electrical power flowing into the motor. When used in conjunction with the ventilation and cooling system of a refrigerator or freezer, a VFD can save energy by decreasing the speed of the compressor when the target temperature has been reached, cycling it on and off as needed.
Air economizers help cool indoor air temperature by drawing air from outside a building when the air outside is cooler than the air inside. The cool air induction reduces the workload of an air conditioning unit, thereby saving energy.
Benefits
Utilizing air economizers and variable frequency drives saves energy by reducing the workload and operating time of a compressor motor. This in turn extends the life of the compressor and decreases utility bills. Depending on the climate and season, energy savings can potentially be very large. In winter months, the compressor may not have to go on for long periods.
NEWS
- "Empire State Building getting $20M green makeover to cut energy costs" Daily Tech, October 18, 2010
- “Integrating lighting and HVAC retrofits” Consulting -Specifying Engineers, October 17, 2010
Resources
- ENERGY STAR: Air-Side Economizer
- Seimens: Variable Frequency Drives
- National Resource Management: Commercial Refrigeration Case Studies
- Boston University: Case Center Upgrade
