If you have an application that calls for a certain capacity at a specified temperature and pressure, and the capacity of the system you are considering lists capacity in SCFM, you need a way to convert between CFM and SCFM. This relationship is derived from the ideal gas law, which uses the absolute pressure reading and the absolute temperature scale. Unlike SCFM, there is no temperature, humidity, or pressure metrics in CFM. The calculator below can used to calculate ACFM: Standard absolute air pressure - Pstd - (psia), Actual absolute air pressure - Pact - (psia), Saturation pressure at the actual temperature - Psat - (psia), Actual ambient air temperature - Tact - (oR), The actual CFM of a compressor operating at "non-standard" conditions like, ACFM = (100 SCFM) [(14.7 psia) / ((12.23 psia) - (0.5069 psia) (80 / 100))]((540 oR) / (520 oR)). Since CFM is based on real-world conditions, the humidity level considered to calculate the unit is inconsistent. There are two types of measurement units, one is the SI units and the other is the non-SI units. All of our electric heater calculators in one place. SCFM, CFM What's the difference? | Tutco-Farnam Chris Deziel holds a Bachelor's degree in physics and a Master's degree in Humanities, He has taught science, math and English at the university level, both in his native Canada and in Japan. If you want to promote your products or services in the Engineering ToolBox - please use Google Adwords. A standard percentage of humidity is considered to estimate SCFM. Here is the complete SCFM to CFM formula we derive further on: CFM = SCFM (14.7 psi Pactual ) (Tactual + 459.67) (68F + 459.67). Here it is: To calculate CFM from SCFM, you need to know what is the pressure (in psi) and temperature (in F) youre calculating the CFM at. Gas Flow Calculator In systems with vacuum pumps, blowers, compressors, and heat exchangers, air pressure and temperature are constantly changing, which means the actual volume flow is changing. } The air compressor CFM is more relevant to the internal capacity of an air compressor. "@type": "Organization", Cookies are only used in the browser to improve user experience. Different industries and standard organizations actually cite slightly different values for what standard conditions are, but we are going to save that discussion for another time. nl to cfm - OnlineConversion Forums