Extractor and fresh intake advice

Hi all,

My growing space is 90cm x 60 x 185 (3' x 2' x 6'2") and I'm hoping to accomodate 3 plants.

There's two parts to the closet with a seperate little top compartment seperated from the main area by a shelf which is where I hope to have the extractor and filter,so will it be ok to vent through the wall (A) as indicated in the pic?
Also could I attach another fan at (B) as indicated to inject fresh air or will that be possible because of the expelled air into the room or even neccessary?

If any more relevant info is needed that's no problem

i would have to say if you are expelling into the wall, you would want to intake from the room.. reason being the air in the wall may be warmer than you need in the grow area... heat from lamps + heat from wall air might not be good.. i am no expert and just recently attempted my first grow ( and i am totally winging it ) but common sense would tell me that hot environment for the plant wouldn't be good, and insulation from wall and or ceiling/floor might be too much hot... that is just my two cents I hope it helped and didn't add to confusion :stoned: