SCFM vs ACFM SCFM vs ACFM Matador (Mechanical) (OP) 5 Jul 05 23:33 Can someone please give me some information on how to calculate the SCFM for a compressor?Flow - 1100 acfmPressure - 100 psigAir Temp - 110 FAltitude - 1600 ftA formula and sample calculation would be great.Thanks in advance RE: SCFM vs ACFM quark (Mechanical) 6 Jul 05 00:01 thread798-106556thread124-95060thread135-97506thread378-90884thread378-97454 RE: SCFM vs ACFM zekeman (Mechanical) 6 Jul 05 19:11 scfm=acfm*(p+14.7)/14.7*530/(t+460)t temp fahrenheitp psig RE: SCFM vs ACFM Matador (Mechanical) (OP) 6 Jul 05 19:28 Thanks for the formula Zekman.Would you substitute the atmospheric pressure associated with 1600 ft elevation instead of 14.7? RE: SCFM vs ACFM quark (Mechanical) 7 Jul 05 02:20 Visiting the above given threads would have cleared your confusion. Actually, the equation for conversion of ACFM to SCFM isACFM = (SCFM x Pstd x T)/[(P-Psat*RH)x Tstd]Where, P and T are actual pressure and temperature in psia and Rankine respectively, Psat is the saturation pressure of water vapor at the actual temperature and pressure conditions. Pstd is standard pressure, 14.696psia and Tstd is (460+60)R.A general standard condition is at 60F temperature, 14.696psia pressure and 0%RH but there are some different values across globe.When you calculate SCFM these are the things you should consider. However, if you are trying to calculate FAD(free air delivery) then atmospheric pressure comes into picture.Regards, RE: SCFM vs ACFM Matador (Mechanical) (OP) 7 Jul 05 10:04 I did read the threads and called the compressor supplier yesterday. The compressors in question were purchased from Sullair and what they call standard conditions are 14.5 psia, 68 F, and dry conditions which i assume to be 0 % RH. There is no mention of the altitude being at sea level.It seems to me they are mixing numbers, They use atmospheric pressure but dry to me signifys a condition after the air dryer.The actual line conditions after the air dryer are known. I'm trying to determine the difference between the nameplate capacity and the actual. Once I determine the reserve capacity, then I have to size a larger receiver to keep the second compressor from loading and unloading continiously. RE: SCFM vs ACFM rorschach (Petroleum) 8 Jul 05 14:56 Compressor manufacturers are very prone to "fudge" thier numbers. Make sure you take thier numbers with a very large block of salt.