# Converting scfm to lb/hr, which density should I use?

• Chemistry
• Frankenstein19

#### Frankenstein19

Homework Statement
If I convert from cfm to scfm, should I use the density of the material at standard conditions or what the conditions the material is actually at?
Relevant Equations
lb/hr = cubic feet/min * 60 min/hr * lb/cubic feet
For air for example at conditions 150 F and 125 psig, density is 0.61lb/ft3

At standard conditions it's 0.0765lb/ft3

If I convert 500 cfm to scfm, does this mean I should multiply by 0.0765lb/ft3*60min/hr to convert to lb/hr?

It is not clear to me what are cfm and scfm, never seen these units (I can guess, but I prefer to be sure).

berkeman and jack action
To convert CFM to lb/hr, you multiply by the actual density. To convert lb/hr to scfm, you then divide by the standard density.

In general the only invariant thing in such calculations is the mass.

Lnewqban said:
The Geneva convention should create legislation to stop America from making units.

BillTre