[deniseO30]

The rubber couplings, are made to fit over the plastic pipe, about 3.5" dia so you would need a stub on the blower

 

[deniseO30]

depending on the installation, squirrel-cage blowers push air well. propeller types pull better.

 

[deniseO30]

Air handling 101 lol. I forgot most of it.

http://www.engineeringtoolbox.com/fan-types-d_142.html

 

[deniseO30]

I have the cage style on mine right now and I am replacing it with an inline. My cage blower is incredibly loud and vibrates the whole boat. I will give it credit though, it does move a lot of air.

you should have a debris screen on the intake.. I could just bet something is inside the wheel throwing off the balance! (very common)

 

[deniseO30]

Ok thinkers.. Don't skewer me if I'm wrong.

Sq wheel fans draw less HP with restricted intake which = less discharge air.

Prop Fans will use more HP if the intake is restricted = less discharge

 

[deniseO30]

FYI, a fan running and not moving air will over amp. Draw more power than when under proper load.

A. Sqrl cage If, the INTAKE has high static, will draw less. At open, or 0 static, amps go up, this I I know from many years in HVAC.

Prop fans or high static types like dust control, I've Really Not played with .

 

[deniseO30]

Let's not forget, these things are pretty small blowers.

 

[deniseO30]

the big box stores have alum 4" pipe and elbows. Most HVAC supply has it also. I'd go with abs black plastic.