Objectives

1
Objectives

• Learn about Fans
• Discuss
• Exam
• Final Project

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Centrifugal fans
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Axial Fans
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Fan Laws

• Approximate relationships
• Given two aerodynamically similar fans, can
  extrapolate performance data
• Be very careful

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Question

• How does fan power consumption vary with
  volumetric air flow rate?

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Controlling Air Flow
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Dampers
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Effect on Fan Curve
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VAV Operation
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Summary of Air Distribution Systems

• Select diffuser based on ADPI
• Given a layout of duct system
• Calculate total pressure drop
• Identify fittings
• Deal with non-circular ducts
• Use fitting loss coefficient or equal length
  method
• Select the fan based on fan and duct curve