Energy Efficiency
Install VFD’s Or Outside-Air Economizers On Fridges And Freezers

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.


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.

Read more about the benefits of air economizers.


Challenge Participants Currently Adopting This Practice

Financing Options, Incentives, And Rebates

Additional Resources

Examples of Boston Area Businesses Using VFDs or Outside-Air Economizers:


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