Confusing the pressure drop with friction rate can lead to significant errors. TT-102 shows you how to read friction charts used with the Duct Calculation Slide Rule.

Topics Include:

• How to read the friction chart given any two of the four parameters (CFM, friction rate, velocity, and duct size)
• The difference between friction rate and pressure drop
• How to convert pressure drop data into friction rate values
• How to use friction rate values, velocity limits, and CFM requirements to determine duct sizes