4000 CFM fan with 3 in static - Please check
4000 CFM fan with 3 in static - Please check
(OP)
Selected 4000 CFM fan with 3 in static for supply air normal application.
Please check if my calculation is correct I have a 20”X14” duct with 113ft running and three 90 degree elbows and two 45 degree elbows.
Thanks
Please check if my calculation is correct I have a 20”X14” duct with 113ft running and three 90 degree elbows and two 45 degree elbows.
Thanks





RE: 4000 CFM fan with 3 in static - Please check
Now, this is just for the duct mentioned.
Have you take into account:
-fliter losses?
-AHU/fan losses?
-dampers?
-registers?
All this needs to be taken into account when specifying the ESP for a fan or AHU fan.
I hope this helps.
RE: 4000 CFM fan with 3 in static - Please check
RE: 4000 CFM fan with 3 in static - Please check
Will you please explain the way you calculated? It will be really helpful for me.
Any easy calculation methods? Thanks in advance
elSid1 -Its SCFM.Thanks
RE: 4000 CFM fan with 3 in static - Please check
It is best if YOU post your work. Easier to correct and see your assumptions. Mech5 gave you the basics items that most forget.
RE: 4000 CFM fan with 3 in static - Please check
RE: 4000 CFM fan with 3 in static - Please check
Thank you for your kind email and clarification of your calculation. It is great to know that you are very detailed in your approach in calculating the static pressure.
Based on my calculation the fan is for a kitchen fan so the static loss at the hood is 1 in. WC and the losses at the bends are greater since they are without veins. I did not calculate the loss at the fan and I did add 10% as a safety. I recalculated the losses again based on SMACNA and achieved a static pressure of 2.8"?
Regards,
RE: 4000 CFM fan with 3 in static - Please check
RE: 4000 CFM fan with 3 in static - Please check
i suggest if you feature all the duct accessories you have from the AHU discharge up to the air outlet.
regards,
Sherif Abulfetuh