Closet ventilation

I have a 5'x2'x8' closet that I'm going to use as a grow room and have a 400w mh/hps light. I am concerned about keeping temps down as I plan to go hydro. My question is this. Will merely running an a/c duct or two into the closet through the attic provide the type of cooling I need. Also do I need to run a bathroom fart fan or something to cycle out the hot air?

Your growroom has nearly the same cubic ft as mine and I'm running a 400w. In hot temps I do exactly what you said, cool my closet with a/c, and use a digital timer to turn my bathroom fart fan on for 5 min every 1½ hrs to refresh the co2.

In cooler temps (60-65f), the bathroom fan works like a charm without the a/c.

Im no expert mate. But i think a 400w may be a bit too much for that size. Saying that it will all come down to your extraction fan if u get a powerfull enough one.

Im in uk so not too familiar with ac units and what they can do.

Youl want a proper centrifugal fan for hid lights and good air exchange. Fart fans just wont cut it i dont think mate.

I tried that with a simiar sized space, 400w sealed light with 6" inline fan and all....it wasn't enough, temps in the space climbed to 90+ degrees. I had an exhaust fan to pull cold air into the room and pull out hot air even.

Here is my closet that is 3.5x8x8 with a 600w in a blockbuster hood.

Here in the UK we had temps as high as 29C and my closet only climbed to 30.4C i do not use AC, but i do use 2 independant fans

LINK >>>>>> https://www.rollitup.org/grow-journals/444034-600w-closet-dinafem-power-kush.html <<<<<<<<


If set up right and extracted correctly using the appropriate fans then you can manage to keep your temps only a few degrees above ambient.


Check it out as the above link is my JOURNAL here is the link to the actual design and setup.


>>>>>>> https://www.rollitup.org/grow-room-design-setup/441212-my-new-closet-re-design.html <<<<<<<

I use 1 fan on a speed controller for the lighting system. And a seperate fan for scrubbing and air exchange.


Check it out it should give you some help and ideas. IF you need anything further dont hesitate to PM me if you'd like.




J

I'm in the exact same size closet, with a 600w light, a stanley blower fan cooling lights and as intake, and a cheap 2 way window fan as my exhaust(1 on the light, 1 for the room), and just a window ac in the room that the closet's in and my temps are ok.

does your closet have attic access if so use that you take out the heat with a 6 inch centrifugal fan

I got the stuff to run an air conditioning duct or two into the closet if I run two ducts do I need to run anything for exhaust or will two ac ducts be enough?

You should always exhaust.

I exhaust my closet into my attic area. The idea is that you need to remove the heat as far away as possible from your grow space.


It is easier to remove heat from an area than it is to blow in cool air.




J

If you dont exhaust then you need to add Co2 supplementation and run a sealed environment.



J

I can also put a fan in the attic to vent hot air. I own my house and can get in the attic

So you need an exhaust fan.

Ideally something centrifugal like a vortex or RVK

You should look at something with around 200CFMs if you want it stay cool. AC units run up alot of electric and to keep one on constantly is pointless if your ambient air temps are pretty good as you can intake cool house air into your area passively through vents.




J

I can also put a fan in the attic to vent hot air. I own my house and can get in the attic

Totoe said:

I can also put a fan in the attic to vent hot air. I own my house and can get in the attic

Click to expand...

Yes i heard you the first time.

Am i missing something here??

I just told you that you are going to need to vent an exhaust fan into your attic to keep temperatures under control.

Do you know how to do this kind of thing?


Or do you need me to run through it with you?


You spent alot of time looking at my Closet ReDesign thread did any of the pictures on there show you how you could run your own setup?


Just mimic it but adapt it to your area.



J

you want the intake to be coming in towards the bottom of the grow. Heat rises, so if you pump in cool air from the top then it will just cool the top of your grow area as the heat from the light coming up will over power it. You want the cool air to come in towards the bottom and the exhaust at the top to suck out the cool air.

My bad earlier i was using my iphone and resent the same reply.

Ok couple questions to make this work best. If I run an AC duct should I run it down to ground level? I got the stuff and just figured I could patch it in to the existing lines in the attic no problem. The exhaust fan might be harder. I thought a bathroom fan would be alright but since that won't work what is best?

you could try using some can fans or inline fans with ducting up to the attic, just put a booster in the ducting leading up to the attic so you make sure you get all the hot air out of the ducts.

I was looking at the good vortex fans online the only thing is I'm getting all my hydro equipment in the mail and assembling it right now so I don't want to have to wait on one from the internet. I'm going to check lowes and home depot for the fans tomorrow and see if they have one so I can get the job done right and quickly. I live in the southern United States so shit can get hot in a hurry down here and I want to have control over it before I start the hydro systems

can I put an 8 inch duct fan in the ceiling and it work fine or do I need to go all out with this shit?