Richard J Kinch wrote:

Grant Erwin writes:

CFM does not equal mass flow

No, this is wrong again. CFM *does* equal mass flow.

I think you don't understand what "CFM" and "SCFM" mean.

One CFM means a cubic foot of air at 1 atm pressure ("free" air), flowing
per minute. Or the equivalent mass of air at any other pressure. It does
NOT mean one cubic foot of air at any other pressure.

I'm obviously not the only one who's "wrong", Richard. Actually, I'm relieved
because now that I understand what you mean by CFM it makes everything you
say make sense. I took it to just be a three letter acronym for "cubic feet
per minute" which could be at any pressure. I did this because my whole adult
life I've seen compressors specified this way. If you try a quick google for
compressor cfm psi
you will instantly see what I mean - everyone specifies their compressors
at a cfm @ a psi.

So it's all a matter of a simple misunderstanding. In the circles you travel
in, CFM has some specialized meaning. To the rest of the world, it simply
means cubic feet per minute.

So what do you call simple cubic feet per minute as a volumetric gas flow?

Grant Erwin