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Managing Energy in Ventilation Systems: Variable Frequency Drives (VFDs) - ON-DEMAND WEBINAR


Electronic (digital download/no shipping)

Member - $99.00
NonMember - $205.00


Ventilation systems are inefficient by nature. Over 40% of the horsepower (HP) in most plants is expended on powering fans and pumps. In ventilation systems for large buildings, variable frequency drives (VFDs) on fans will save energy by allowing the volume of air moved to match the system demand. Current VFD costs have decreased in recent years to a point where they can be incorporated into almost all ventilation designs. They also have flexibility of control and offer considerable electrical energy savings through greatly reduced electric bills. VFDs also have special requirements to provide stable operation and to maximize energy savings potential. This webinar provides key information regarding the use of VFDs as well as how they work to reduce plant operating costs. Practical examples are demonstrated during the webinar.

The presentation follows the following outline:

  1. Energy Costs in Ventilation Design Horsepower Formula
  2. Volume and Pressure for System Operation
  3. Basic System Pressure Calculations
    1. Components of system resistance
    2. Effects of density on system operation
    3. System static pressure curve
  4. Basic Fan Curve
    1. Effects of changes in fan speed
    2. Effects of changes in density
    3. Horsepower curve
    4. Where to operate on fan curve
  5. Changing Fan and System Curves
    1. Operation at intersection
    2. Changing system curve with pressure (outlet dampers)
    3. Changing fan curves with dampers (inlet dampers)
    4. Changing fan speed (drive changes and VFDs)
  6. Operation of a VFD
    1. Method
    2. Effects on changes to HP
  7. System Goals
    1. Constant volume
    2. Variable volume (central plenum)
  8. Potential for Bad Fan Performance
    1. Operating point on curve
    2. Change in density
    3. Change in flow or pressure requirements
  9. How to Proceed
    1. Know your fan and system curves
    2. Understand how they may change during operation
    3. Manage density
After participating in this webinar, attendees will be better able to understand:
  • How the use of variable speed systems can help a large building save energy
  • How VFDs can be used for improved system reliability and system life
  • How system and fan curves interact
  • The system curve in a variable pressure system
  • How air density affects fan and system curves

This webinar is 2.5 hours in length and may be eligible for certification maintenance points.

Product Details:

Product ID: WB-011-USB
Publication Year: 2008