Cool Tube Question

I have 2 400watt mh lights that i am making cool tubes for out of bake-around tubes. I want to have both of them going to one exaust using a y connector but i dont know how i should cap off the open ends of the tube.

Any help would be appreciated

Are you making the lights separate of the room venting, if not I have a ac hood and its open at the end to my room I put some panty hose on the end so when the fans off nothing flies in.

yea im gonna have the cool tube exaust seperate from the room exaust

Ok so then you should have the other ends of the cooltubes go to fresh air or where you get the intake air from outside the grow area. Ive seen a room before where they used 1 fan to exhaust everything out and a phylum(not sure if that is the name) pretty much a box where all the exiting air would need to meet up and connect to the 1 fan. Air acts like a fluid. I hope this give some type of ideas you could use.