Objectives

Learn about Fans

Discuss •Exam •Final Project

Centrifugal fans

Axial Fans

Fan Laws

• “Approximate relationships”

• Given two aerodynamically similar fans, can extrapolate performance data

• Be very careful

Question

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

Controlling Air Flow

Dampers

Effect on Fan Curve

VAV Operation

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