getting rid of the odour

yo cannabis dot com quick noobie q; what are the chances of my mate getting gripped? hes growing a small bunch ofplants for himself, only 3 plants total from his flat, its halfway up a high rise block. Got it vented out the window n theres about 15 flats above me, oops him i mean, and about the same amount of stories below. Risky?

Was thinkin of buying him a mega powerful extraction fan for his birthday, setting that up then narrowing the exhaust toward the exit out the window to create a sort of venturi effect in turn increasing the velocity the odour exits at, obviously 'firing' it further away from the flat hopefully avoiding detection, thoughts? anyone done anything similar?

Carbon filter, buy the size that will fit you exhaust fan & for size of your room. It works & well worth the money.

thanks for the reply, regarding the carbon filter, just wow, that is an awesome idea if it works i imagine there would be no odour risk whatsoever.. Will i need more than one to be on the safe side though or should it be alright on its own? Wheres the most effective place to use it, some places say intake, some exhaust and even that you should hang it up... If you used one would you be able to tell there were plants in the room?

You can also buy a little window flower holder nd put a bunch of herbs in it. Like real herbs like rosmary and some sage nd stuff. Stick them in the sill of the window he's venting from if they'll fit, the smells will all mix together nd it'll be hard to identify it as only one substance. I have a carbon filter attached to my online fan nd it works miracles. Well worth the dollars.