Venting to attic, two 8" fans, advice please.

Im running one 8" fan to cool two 1000w lights and one to filter, will there be any problem using a splitter duct into the same outlet in the ceiling?

A y splitter from the lights and then use the filter in the attic. Blow out of the filter instead of sucking in.?

"Blow out of the filter instead of sucking in.?"
Can you do that?

Not sure about blowing out the filter but the duct thru the lights goes outside > lights > ceiling so no air needs to be filtered form it. But I only have one hole going into the ceiling, I have a big splitter from home depot, kind of a Y shape. Wondering if the fans both blowing into this one splitter is going to cause a issue?

Shouldn't have to filter lights if you have sealed hoods and intake outside the growroom.

If you live in Seattle, venting into the attic and leaving it there is a real bad idea. I almost rotted my roof, years ago.

You can push air through a carbon filter but I've heard fans work better pulling against the restriction. You also lose the prefilter unless you add them at the other end.

Having two identical fans, one pulling air through the lights from outside the room and the other pulling through a filter . . . the filter fan is going to have extra resistance pushing the air into the attic because the light fan doesn't have a filter dragging it down . . . unless it is a long duct run with lots of bends . . . so I guess I'm saying be prepared to dial down the speed of the light fan so each airflow is about equal when they meet at the wye.

sanjuan said:

If you live in Seattle, venting into the attic and leaving it there is a real bad idea. I almost rotted my roof, years ago.

You can push air through a carbon filter but I've heard fans work better pulling against the restriction.

Having two identical fans, one pulling air through the lights from outside the room and the other pulling through a filter . . . the filter fan is going to have extra resistance pushing the air into the attic because the light fan doesn't have a filter dragging it down . . . unless it is a long duct run with lots of bends . . . so I guess I'm saying be prepared to dial down the speed of the light fan so each airflow is about equal when they meet at the wye.

Click to expand...

Ahh, thats what I thought might occur, both fans needing equal air pressure... I live in oregon in a very rainy place, I fave a large vent on the side of the roof ill be running my ducting directly to so its blowing straight outside. That should work right?

Sounds good. I use insulated duct in the attic to prevent condensation during cold weather. At the other place, putting a big box fan between the attic and an attached garage was enough to stop the rot.