backward inclined blower with no housing

[slowwilly]

I have a situation where I essentially need to suck air through a long section of ductwork and discharge it to essentially the atmosphere.

Suction pressure will be around 5 inches H2O and discharge pressure will be small, around 0.1 inch.

Let's say I take a fan rated for 500 CFM at 5".

If I remember correctly, a large portion of a blowers pressure performance comes from the housing design. What happens if I remove that housing & simply have the suction portion of the blower hooked up to my fan (ie I keep the "face plate on the suction side, but remove the rest of the housing)? Will I get 500 CFM through my ductwork, more or less?

Thanks

 

[RossABQ]

You are describing a plug fan arrangement. If the wheel is in a large plenum, it might work OK, but all bets are off on the original fan curve.