Phredh Filter + Duct fan?

I can only afford a 4" Phresh 200cfm Carbon Filter.
My question is:
Do you think a 8" 400cfm duct fan would work with it?
Maybe install a speed controller as well?
Anybody got any experience with a similar set-up?
How did it work for you?
I heard duct fans are usually +/-150cfm then their indicated cfm rating depending on whether it's installed in an duct system with air flow.
Let's just just mine has no airflow going through it. So it be at 250cfm.

You definitely want a speed controller. If you move more air than you need to, the carbon filter won't be as effective. The longer the air circulates through the carbon particles, the more effective the odor neutralization. At some volume it will be so ineffective that you'll be able to smell it. (More likely, you'll be nose blind and *others* will smell it -- as you think you're safe).

You think it would be smart to get an Apollo 190Cfm Inline fan?

az2000 said:

You definitely want a speed controller. If you move more air than you need to, the carbon filter won't be as effective. The longer the air circulates through the carbon particles, the more effective the odor neutralization. At some volume it will be so ineffective that you'll be able to smell it. (More likely, you'll be nose blind and *others* will smell it -- as you think you're safe).

Click to expand...

Being a little slower then the Phresh Cfm would help filter out the smell a little better right?