Need Help With Blower CFM Sizing 1

[dfowler]

I am building a pressure chamber that is 10'deep, 13'tall, and 22'wide. It is to be equally divided in depth so both sides are essentially 5'x13'x22' in volume. This will be used to test variable pressure loads on garage doors to be placed in between the two halves of the chamber. The variable pressure loads will then correspond to effective pressure from different wind speeds.
The volume of air on each side of the door is approximately 1400 cubic feet. I want to use a blower to suck from one half of the chamber and blow into the other half.
The test criteria is that a pre-load be placed on the door (a pressure delta of only about 2 psi or 30 pounds per sq ft.) for one minute. The door is unloaded and then the test load of twice the pre-load (4 psi) is enacted for one minute. The door is unloaded again and then the safety load of 1.5 times the test load (6 psi) is placed on the door for 10 seconds.
Minimizing the time to reach full load is crucial especially for the safety load so I want to size my blower fairly large even though the pressure differential and the volumes are relatively low.
I realize that control over the blower speed alone would result in slow response time for pressure adjustments in the system. Therefore I want to run the blower at full speed and divert most of its flow into a duct with a control valve looped right back into the blower intake. This could be pinched off slowly to deliver more pressure/ suction to the test chamber with better control.
With these volumes, time frames, and pressures (specifically the delta of 6 psi) could anyone suggest a proper blower size in cfm? Or better yet a good source or handbook that I can look up easy to use formulas for air flow and pressure differentials. We are plastic wrapping the door and assuming minimal air leaks between the halves of the test chamber.
I am a mechanical engineer with minimal HVAC exposure. Thanks in advance for any help!

David Fowler

 

[Carnak]

Interesting thread, reminds me of a problem I had with a potential fire supression system.

The client was an international company, and their UK based Envrironmental People did not want FM200 fire suppression to be used. They opted for argonite a 50/50 mixture of argon and nitrogen. This system work by displacing air and therefore oxygen. It is very similar to Inergen, if that rings a bell.

The gas gets released in perhaps a one minute time span, and displaces close to 40% of the room air. Without a means of pressure relief, I figured pressure could rise by as high as 6 psi, and I was forced to design a pressure relief system.

Maybe some compressed nitrogen is what you may want to consider. Try talking to someone who sells Inergen concerning controls, manifolds, valves etc.