Make-up air for air compressor
Make-up air for air compressor
(OP)
Hi all,
I have an air compressor (7.5 HP, 16.8 acfm @ 175 psi) in a confined space. I was thinking of putting a small louver in the exterior wall for make-up air. How big should my louver be? Or what is the required free area? Thanks.
I have an air compressor (7.5 HP, 16.8 acfm @ 175 psi) in a confined space. I was thinking of putting a small louver in the exterior wall for make-up air. How big should my louver be? Or what is the required free area? Thanks.





RE: Make-up air for air compressor
you may find that it really isnt too much. then it should not be too hard to convert your needed Absolute cfm to an areal flow rate. Then just size your louver 200% and no troubles, even when cottonwood and other fluff fills the screens.
RE: Make-up air for air compressor
RE: Make-up air for air compressor
RE: Make-up air for air compressor
I think you are confusing temperature rise across the compressor with the conversion from ACF to SCF. At sea level on a 60F day, ACF = SCF. In Garfield County Colorado(one well in that county sits at 10,000 ft and has an atmospheric pressure of 10.1 psia) on a -30F day then the conversion is:
SCF = ACF * (10.1*(460+60))/(14.73*(460-30) = ACF * 0.829
The reason for the conversion that flow equations are stated in SCF. Your inlet plennum should be sized for either a specific pressure drop or a specific velocity. I like to use velocity less than 5 ft/sec on the suction side of an air compressor (this is really arbitrary, I picked it up from a grey-haired old fart early in my career) so at sea level I get 3.2 ft/s in 4-inch for your 16.8 SCF/m. If you want to go with NickE's advice of doubling the size, a 6-inch would give you 1.4 ft/sec.
David Simpson, PE
MuleShoe Engineering
www.muleshoe-eng.com
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.
The harder I work, the luckier I seem
RE: Make-up air for air compressor