I have three fans connected separately to the same 6" ducting. I have two rooms, two fans in one room and another fan in the other. This ducting provides them the cool fresh air they need from yet another room. However, since they are connected to the same line when the fans run separately they pull air from the opposite room which contains hotter air. So my room temp in my veg cabinet hoovers around 82-85 degrees.

The only thing i figure i can do is make a flap that drops down to cover the opening when the fans are off. But can't quite think of how to do it. Any thoughts or other ideas?

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I've found that when it comes to ventillation setup, the more simple the better.

It sounds like you have a lot going on, and probably a whole lot of ductwork. There's static resistance in the ducting that creates problems, so the shorter the lines the better.

I have 6 600W lights with one exhaust fan that pulls air out of the grow room through the hoods, I just have an ambient intake.

If you can simplify everything it'll probably work out fine.

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show me a pic

I hear that, about the simpler the better. But i have a 1k hps and and a 400 mh. Each room just gets really hot. So i gotta have the vent system the way it is. But i figured it out. I'm ordered some vent dampers, they are like shutters to put at the end of the 6" ducting and will close when the fans are off. Thereby eliminating the problem of pulling hot air from the opposite room. I hope this gets the temperature down.

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I am more afraid of an army of 100 sheep led by a lion than an army of 100 lions led by a sheep.

it is a simple matter of pi-r-square. IF you insist on trying to run these lines together, just use the formula to find the capacity of the three seperate 6" lines, and make your exit line that size. a 12" diameter exit might do it. Or you could drop to 4" lines, in that case you could probably do it with an 8" exit. Backdraft dmpers will not solve the pi-r-square problem you have. VV

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It's a little early to be doing geometry and algebra... Isn't it VV?



--You're having problems overheating a 1000W and a 400W?

Post # 1 is like a word problem...

I think I can solve it...

I believe you have one duct that travels through each light, through two rooms, and into a third...

Simplify it by eliminating the hassle.

I think if you just run one vent from each hood to your third room, and pull/push air from the hood into the third room it'll work out.

You'll be sucking air out of the growroom, and blowing it into the third room, so you might need a passive intake for the grow room, but there's probably enough gaps in the walls, under the door, etc so it wont be an issue.

On the other hand, you could run your vents 24/7 so you won't have a damper problem, but I think if you simplify it you wont have any issues.

On the hood, one end is open, the other end has a vent sucking ambient air through the hood... That's my solution.

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get a sledge hamer and bust down the wall and make it all one room

that would work too, but make sure it's not a load bearing wall...

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Tada! I drew it for you guys to see. the room with the 400watt is my veg room that will host my mothers. The 1000 watt room is my bloom room where i'm doing SOG. The two rooms are in a closet next to a bedroom.

Attached Images

VF Diagram1.jpg (61.1 KB, 52 views)

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I am more afraid of an army of 100 sheep led by a lion than an army of 100 lions led by a sheep.

I'm not sure a closet qualifies as two rooms... I'm thinking it's one of those sliding door ones, 8ft x 4ft...

That's a tight enclosed area to house that much wattage...

And your vents are definately complicated as hell.

Try pulling air out of both rooms, through the hoods, and make the "cold air from bathroom" be your vacume line, make that bathroom a sauna, pull hot air into it, passive intake from the bedroom will work fine.

I'm willing to bet you this will work, make yourself a sauna in that bathroom, I know at least 7 growers that do this personally, not on here, I always have a room like that where all the hot air goes...

If it's hot where you are you could always scrub it and exhaust it from the house instead of the bathroom, but it's cold as hell here, and that will save you some cash on the heating bill.

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