Intake & Exaust

[1hitter]

Hi again, Ok here is my problem hopefully someone can help. My grow box is in my garage I live where it gets hot but right now my garage temp is only 78 but my box temp is getting up to 92. I have a 6" 160 cfm duct fan for exaust right now. I have a 6"x6" intake with a light defuser I made, also have a 5"x5" hole with a defuser I made also have two 2" 90s. If I open the doors I get with in 2 degrees of the room temp but with them closed the temps shoot right back up. So here is my question could I go to radio shack and pick up 2 small computer fans and put them over my intake to help increase air flow?

I have not found any other way to block out light which is why I made the defusers. Any other ideas would be great.

[Pullo]

The fact that your temp. problem is resolved when you open the doors, leads me to believe that your intake is either too restricted, or not large enough.

We need to ask a few basic questions first:

How big is your grow room? (dimensions W x D x H)
Where are your vents?
Do you have many bends in your exhaust line?
What type of lighting are you using?
Could your light diffusers be to restrictive?

Lets start with those and see if the GP team can take care of this.
Just wondering but, did you look in the FAQ about ventilation?

Hang tight, help is on the way.

Pullo

[MedGarden420]

My room the temp stays down nicely till I open the door and then it heats up in there after only a half hour. But if it gets hot outside, I have to turn the air conditioner on in the room where the intake is to cool it down. But I would have to turn it on when it gets hot anyway. :-)

[chaos420]

To make my box light-proof, I just used a thin hepa filter (or vacuum bag) and dyed the outside black.. Don't know if it would be less restrictive than a diffuser. As an experiment, take the diffuser off and moniter the temps.

If the diffuser is the problem, then build a vent to put over the intake. If built right, it will be lightproof with very little restriction. Remember, light can't turn corners... Something like this should work-

(I know you're in awe of my drawing skills)

[1hitter]

Originally Posted by Pullo

The fact that your temp. problem is resolved when you open the doors, leads me to believe that your intake is either too restricted, or not large enough.

We need to ask a few basic questions first:

How big is your grow room? (dimensions W x D x H)
Where are your vents?
Do you have many bends in your exhaust line?
What type of lighting are you using?
Could your light diffusers be to restrictive?

Lets start with those and see if the GP team can take care of this.
Just wondering but, did you look in the FAQ about ventilation?

Hang tight, help is on the way.

Pullo

Ok grow room is 36" w 18" d 42" h
vents are down near the bottom except the 5x5 it is about 1/2 way up the side
No exhaust line
312 watts of cfl
yes the diffusers are restricting air flow, I could not figure out how to block light with out the diffusers also i made them because of money issues.

[Pullo]

OK-

Your room is just under 19 cubic feet, with a 160 cfm fan you should be able to exchange the air in your room 8 times a minute, which is well above the minimum of once in five minutes, so far this does not seem to be happening.
You said your garage temp was 78F?
Lets try this, when your lights are on, remove the diffuser and see if your temps go down(I assume you have a thermometer), if so we know where to start.

What is the vent for mid-way up the cabinet?

[1hitter]

I didn't have room to put it on the bottom so i put the small diffuser just above the big one.

[rapt0r]

I've got the same worries about if I setup my cabinet in the garage, except it does get quite warm in my garage... an Idea I though of would be to draw in cool air from under the crawspace of the house (if you have one that abutts the garage, a two or three inch hole for source air may provide the adequate 10 to 15 degree cooler air to keep the temps in the cab down) just thinking out loud... down in my neck of the woods there are no basements... I miss the Northeast.


-rapt0r

[Pullo]

Use some tape or paper to cover the vent that is mid-way up the cabinet.
Remove the diffuser completely on the bottom(there should just be a hole there).
Turn your fan on, and watch to see if the temp. drops.

If you don't have any exhaust lines, does the exhaust side if the fan just stick out of the top of the box?
Is it an inline fan, or a bathroom fan?

Try that test with the vents, and we can go from there.
I had a hell of a time getting my cabinet venting and cooling fine tuned. It was one of the reasons I picked CFL's, because I thought they would not emit too much heat, but once you stuff things in a small cabinet and turn the power on, you just can't avoid it.

[jangel]

One other thing you can do is go to home depot or any building supply place and buy 4 inch or however wide your hole is plumbing parts, and do it just like the pic that chaos drew. make the pieces fit together in an s shape, and it will not restrict the air flow but will block the light. If you use black UBS pipe or sewer pipe, it will work and you can just put them together without glew and they will stay. I don't think that would cost much at all, and you would not need a light blocker.

Peace

[justplainbill]

The intake is too small. It should be larger than the exhaust.

[Pullo]

Originally Posted by justplainbill

The intake is too small. It should be larger than the exhaust.

I just noticed that, he is already one inch under the minimum.
I also thought that the lower your air intakes the better, the air is cooler and should contain more Co2.

[1hitter]

Originally Posted by rapt0r

I've got the same worries about if I setup my cabinet in the garage, except it does get quite warm in my garage... an Idea I though of would be to draw in cool air from under the crawspace of the house (if you have one that abutts the garage, a two or three inch hole for source air may provide the adequate 10 to 15 degree cooler air to keep the temps in the cab down) just thinking out loud... down in my neck of the woods there are no basements... I miss the Northeast.


-rapt0r

I was thinking about that today but I live in the southeast and it gets pretty hot. I am thinking about buying an ac unit to put next to the cabinet and putting an intake fan to draw in the cold air.

[1hitter]

Originally Posted by Pullo

Use some tape or paper to cover the vent that is mid-way up the cabinet.
Remove the diffuser completely on the bottom(there should just be a hole there).
Turn your fan on, and watch to see if the temp. drops.

If you don't have any exhaust lines, does the exhaust side if the fan just stick out of the top of the box?
Is it an inline fan, or a bathroom fan?

Try that test with the vents, and we can go from there.
I had a hell of a time getting my cabinet venting and cooling fine tuned. It was one of the reasons I picked CFL's, because I thought they would not emit too much heat, but once you stuff things in a small cabinet and turn the power on, you just can't avoid it.

I am using a duct fan and have it sticking out the back of the cab with a 90 on it right at the top of the cabinet. I will try removing the diffuser in a little while off to a birthday dinner for my nephew right now.

[Pullo]

I've got no experience in that department 1hitter, but have no doubt, someone will have some answers for you.

[1hitter]

Originally Posted by jangel

One other thing you can do is go to home depot or any building supply place and buy 4 inch or however wide your hole is plumbing parts, and do it just like the pic that chaos drew. make the pieces fit together in an s shape, and it will not restrict the air flow but will block the light. If you use black UBS pipe or sewer pipe, it will work and you can just put them together without glew and they will stay. I don't think that would cost much at all, and you would not need a light blocker.

Peace

How many 4" holes would I need to vent my cabinet?

[Pullo]

You need at least 8 square inches of area.
Is your fan the kind you get at Home Depot to be put into a duct to help boost flow?

[justplainbill]

Get a window unit and cool yourself too. I like to push the air in rather than suck it out. Then you make the exhaust hole a bit smaller than the supply hole. That way you have a positive pressure and will blow air out of the cracks etc, instead of sucking it in.
Good luck

[1hitter]

Originally Posted by Pullo

You need at least 8 square inches of area.
Is your fan the kind you get at Home Depot to be put into a duct to help boost flow?

Yes it is, it's made by Suncourt and according to their web site it is 160cf free air.

[Pullo]

I use the same fan as a "booster fan" to help exchange the air in the room that my cabinet is in.
I first installed it in my cabinet as my main exhaust fan, but it just was not up to the task, at least it was not right for my application.