Air Flow Pressure Drop

[Futsal]

How do I determine the pressure drop of air across an opening? For example if I have 3,000 L/s (3 m³/s) and an opening of 8.4 m² I know the velocity is 0.4 m/s. If the free area is 80%, the velocity increases to 0.45 m/s. What I'd like to cal is the pressure drop in each case.

Cheers

 

[willard3]

You look either in SMACNA or ASHRAE volumes.

This should probably be posted in HVAC.

 

[chicopee]

Willard 3 is right; also unless you give us more details about the entire set up, I venture to guess not more than 1 in H2O.