Proximity of Fan & Carbon Filter

I've constructed a "high tech" grow cabinet from elegant wooden furniture, (photos coming soon). It's got an air cooled reflector, seperate air souce...anyway

I'm installing the carbon filter and fan and since there's limited space to work with, I wanted to know if there's any performance issues with having too long of a distance between the filter and the fan.

Most photos/videos I've seen with grow rooms and closets show the fan almost touching the filter.

with my set up, it would be ideal if I could put about a full 12" of mylar ducting from filter to fan.

Any advanced thoughts on this would be great.

you can seperate the fan from the filter, but the longer the vent gets between the two the less true cfm youll be getting from the fan. basicly the ducting creates air flow resistance. so keep that in mind, also by streching the venting so there are no creases or minimal creases this will help in reduceing the resistance. same thing applies when tuneing a sub box with aero ports. air resistance is a killer.