Tractorsport Flowbench Forum Archive

Posted: **Tue Apr 26, 2005 12:21 am**

Anyone know what the formula is to convert air watts to cfm is.

Posted: **Tue Apr 26, 2005 9:14 am**

There's not a direct conversion from air watts to cfm because one is energy, the other is flow. You'd need to specify a pressure differential for your flow to be able to calculate cfm from the air watts. Beyond that, I can't help you, in fact, I'd like to know too.

Posted: **Tue Apr 26, 2005 8:14 pm**

I found the formula for air watts = cfm x H2O"/8.5. As near as I can tell, using all six of the vacuum motors from Surplus Center, the GS Electric ones, I can flow 596 cfm @ 28" of water. (596 x 28")/8.5 = 1963.29 air watts, an average of 327 air watts per motor. This is old data from some of my initial runs with the bench so the figures should not be taken as hard fact and maybe some others would offer their results. This was tested with the test port wide open pulling through a 3" flow tube using Bruce's averaging pitot tube. The test port was restricted with a plate partially blocking the test port until 28" of lift was reached on the vertical manometer.