Does exhaust fan have to be inside box or can it be at the end of the deuct of the exhaust

Hey guys, just a general question, just planning my first ever grow, working on building a custom wood grow box. I have a 6" in-line duct fan but am unsure if it needs to be placed inside the box and then duct from it to the roof vent. Or if I can simply cut a hole in the box and attach the 6" ducting, and place the fan near the middle or end of the ducting run (could be 2'-5' away depending on where i place the box in the room)

Does it matter or is there a best option? Only reason I am debating putting the fan down the ducting is for noise, I havent heard it run yet but if its running 24/7 and Im going for a slightly stealth build, keeping the noise down would be ideal. As a side note this will be venting a 4X3.5X5box with 240watts of T5 flourescent

Cheers!

I run the fan at the end. I have an inline carbon filter before it.

I wont have a filter, atleast for the first grow (want to see if northern light are as tame as said to be smell wise)

it does not matter where you put your fan really, but just in case you need a carbon filter you want your fan after that they work better sucking air then blowing air good luck

Thank you, Im going to place it about 3' downstream just so it is on the other side of the wall

Just make sure everything is sealed well so the fan is actually pulling the air out of the box