/, Contextual, Cooling, Electric devices, Heating, HVAC, Long term, Offices, Operators, Owners, Physical environmental, Psychological/2.2.5 Installation of Variable Frequency Drives (VFDs) on motors

2.2.5 Installation of Variable Frequency Drives (VFDs) on motors

2.2.5 Installation of Variable Frequency Drives (VFDs) on motors


VFDs efficiently meet airflow or water flow variation requirements by adjusting the frequency and voltage of the power supplied to an AC motor to enable it to operate over a wide range of rotational speeds. External sensors monitor flow, liquid levels, or pressure, and then transmit a signal to a controller that adjusts the frequency and speed to match process requirements.


  • Small decreases in equipment rotating speed or fluid flow yield to significant reductions in the energy use. For example, reducing speed (flow) by 20% can reduce power requirements by approximately 50%

  • VFDs also allow the savings of energy consumption at the start-up

  • Reduce wear and tear on the motors

  • Provide more precise levels of control of applications


  • In Direct Current (DC) motors, the relationship between power and speed is directly proportional, so the savings are not so high

  • The profitability of a VFD increases with the load variation and the number of working hours

Economic assessment

Investment: medium-high.

Payback: high.

References and best practices

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Environment or playable world:

  • Residential

  • Academic

  • Offices

  • All

Carried out by:

  • Public building users

  • Owners

  • Operators

  • All

Reduce consumption of:

  • Heating

  • Cooling

  • DHW

  • Lighting

  • Electric devices

Type of driver:

  • Physical environmental

  • Contextual

  • Psychological

  • Physiological

  • Social

Time framework:

  • Short term
  • Long term

Type of measure:

  • Envelope
  • HVAC
  • DHW
  • Lighting
  • Electrical devices
  • Other
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