I'm not certain that a computer fan is rated at enough air flow to force air through that scrubber.
Just for comparison, you need an actual BLOWER to run an odorsok properly, which is about the lowest-air-resistance carbon filter I can think of.
I think that guy may be ripping people off with a product that does not perform up to what is expected of it.

More ducting will quiet it down, but you may have more significant problems.
foxysox Reviewed by foxysox on . HELP! SILENCER BUILD IDEA! So i Have This Activated Carbon air Scrubber. i bought this off ebay from a man who makes them and sells them ebay member" aeroscrog" if any one is interested. this scrubber is attached to a 5 inch box fan. deffinitly a computer fan. But the sound the fan makes (with the air "wooshing" not the motor) a lot of noise. I want to build a silencer for this. from my Home box xs i have about 8 inches max of back space. does anyone have an idea how to build this silencer. How to attach a box like Rating: 5