i have got two 6" vent-axia commercial powerflow fans that i plan to use in my first grow . (that is still in the thinking stage but soon to progress ).do i use 1 fan for extract and 1 fan for intake ?

or do i use 1 fan for extract mounted at the top then make a bigger hole in the bottom of the room and have some desktop fans inside ?

any help on this would be much appreciated

use one in one out but i would turn intake down cos once you put a filter on the extractor it will slow down it airflow abit

and you want negative pressure

thanks for the reply ....

As JIffa said, you want negative pressure to make sure no air/smell escapes. The filter will add resistance to the extraction, either get a fan controller for in the intake or mayeb try and swap it?

i have two fan controllers so if i set the extract to run faster than the intake then that should be o.k right ? the fans are quite

powerful so i dont think they will be running at full speed anyway

once you add the filter