Makes sense. Heres the thing though. By pulling air from within the room, through the hood, it IS keeping my hood super cool but, most importantly... by pulling air from in the room it is sucking cold air into the room like crazy through the passive vent (outdoor cold weather). It's like a fan in self. It is amazing how the passive blows cold fresh air into the room when the vortex is on.

I have not tried to hook that filter up but I'm guessing you are correct. It will choke it somewhat. I'll have to see what happens to the temp.

Where would you put the filter?

I know we have got a bit side tracked = ) But I do really appriciate the advice.