Fan sizing for heat removal
Fan sizing for heat removal
(OP)
I am a non-HVAC mechanical engineer that needs help. I have an industrial machine application where I need to determine the required fan size. I have determined the required CFM based on heat removal only (no losses in the duct). My duct has an area contraction, a 90 deg elbow and another area contraction due to packaging limitations. The total length of the run is less than 5 ft. Do I simply calculate my friction pressure at each contraction and the elbow and add them together, or is there more to it? Any information would be helpful.





RE: Fan sizing for heat removal
RE: Fan sizing for heat removal
The CFM will not change due to your ductwork. What will change, though, is the static pressure you need to specify your fan for. The static calculations will need to be as you have said. I would also add a safety factor of your choosing.
Just to be sure you have sized your CFM properly, did you use a formula similar the the following:
CFM = BTU /(1.08 * (Delta Deg F))
Hope this helps.
RE: Fan sizing for heat removal
operating ambient for motors, transformers). CFM = Btuh/(1.1 x TD) Where TD = 104-outdoor air design temperature.
RE: Fan sizing for heat removal
Would you please state the CFM, pipes, elbow, and transition duct size?????
Pardal
RE: Fan sizing for heat removal
Yes, 62hog, that is similar to the formula I am using.
I have determined I need 500CFM to cool a rollerscrew that is generating heat. The fan is pulling in air from the plant through a filter. The plant air could easily reach 110F in the summer. The duct is as follows - 38.21 in2, contracts to 19.10 in2, 90 deg elbow, contracts to 12.46 in2, exits to rollerscrew. My initial calculation shows a static pressure drop of .56". Does this sound reasonable???
RE: Fan sizing for heat removal
RE: Fan sizing for heat removal