Carbon filter set up help

Any one got a opinions on how much ducting I need or does it matter I'm using a 4 inch carbon filter with a 4 inch inline fan also is this correct the way the air flow running in the picture to pull air though the carbon filter, any help would be much appreciated

The optimum way is to pull through the filter.

Filter —- fan —— out

Ive always found fans pull air much better than they push.

Measure the distance between the fan exit point to the window or where ever your going to pump the heat.and give yourself some spare.

Check your fan is less cfm than the filter. That filter looks tiny.