Pressure Losses

[engggu]

Hi Guys, may i know what will be the calculation for losses of this type duct. I will be selecting fresh air fans for my ahu rooms

Friction losses
Entry losses
Exit losses

Please see attached thank you

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[BenMacier]

What about starting to read the ASHRAE guides or equivalent HVAC codes in your country first?
Then if you have questions for a particular configuration you're not sure of how to interpret the guidance, feel free to post it!

 

[GT-EGR]

Use ASHRAE duct design manual or duct fitting database and find nearest equivalent fitting and make a judgement if this is better or worse. You could nearly call that a 90 deg mitered elbow with no vanes, and then an entry and exit loss if applicable. Don’t forget the screen which I believe is also an ASHRAE item as well.


Don’t forget how you connect the fan to that intake and how close it is and the fan rotation may have it’s own system effect beyond just looking at that as a simple duct fitting though.