Wish I weren't so stoned...maybe I could help understand.

If you suck air in thru the filter, you are sucking indeed. But, if you are just blowing the air right back into the grow room, you are not accomplishing anything other than air scrubbing.

You are essentially placing hot air right back into the room from which it came from. That leaves little room for fresh CO2.

If you have a fan sucking air thru the filter, then you have tubing or other shit you are exhausting it thru, you are still PUSHING as well as sucking.

Hence the term vortex.

The end result is the same. These high end fans have extremely high static pressure levels and will push as well as pull. There is no difference and again, if you are dumping the air back into the grow area, even if thru vented hoods, you are only scrubbing the air.

Maybe when I not so high I can understand better....but I dont know when that time would be....