# Ventilation



## ugmjfarmer (May 17, 2008)

I will be running a 400w HPS in a 32" x 24" x 8' closet room. My plans are to use a 95CFM 4" Cage fan and vent into the attic of my house. 

Should I worry about an intake, or should I just overdo the exaust fan and pull air from the crack under the door? I know there will be sufficient negative pressure if there is enough exhaust. 

Also my concern is stealth. How loud are 100+ CFM exhausts?


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## PeaceKiller (May 17, 2008)

Hi ugmjfarmer,

How high is the crack under the door? 1/4", 1/2", maybe 1"?

As for fan volume, I have a Valueline 435 CFM, and the thing sounds like a freakin vacum cleaner, however its really powerful. To counter this noise, I bought a Fan Speed Controller (I think they are only for inline fans, not squirrel cage), and now I have turned it all the way down. It still pushes a lot of air and it is much more bareable noise wise (a little humming maybe like a computer but just slightly louder). Hopefully someone can chime in on this issue.

My only concern, is yours.
I'm sure you will have the negative pressure, however it may not be enough and you may have heat build up. A cool tube or sealed reflector would be very helpful in keeping down heat.

Is this exhaust only for heat or for odor as well?


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## camcam (May 17, 2008)

If you have a noise problem with the fan unit just build a box round it and pack it with fire resistant foam, it is amazing! I once had a inline fan that was 780 m3/h and it sound like a boeing 747 setting off, I made a box filled it with fire resistant foam and it was almost silent.

Can't you put a vent on the bottom of the door?


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## JohninWI (May 17, 2008)

I helped a friend with a problem like that.  We put the fan in a box built from particle board and covered in fiberglass insulation/duct tape.  Then we routed the air output through a 6" flexible duct pipe---the insulated kind you can buy at any home improvement place.  It went from the "vacuum cleaner" sound to a noise so low you have to be in the room with it to hear.  

I don't know what size the squirrel cage fans were.  They were actually recycled from the vent system on a gas burning water heater.  Excellent quality.


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## Puffin Afatty (May 17, 2008)

ugmjfarmer said:
			
		

> I will be running a 400w HPS in a 32" x 24" x 8' closet room. My plans are to use a 95CFM 4" Cage fan and vent into the attic of my house.
> 
> Should I worry about an intake, or should I just overdo the exaust fan and pull air from the crack under the door? I know there will be sufficient negative pressure if there is enough exhaust.
> 
> Also my concern is stealth. How loud are 100+ CFM exhausts?


 
_I use constant co2 so I have constant exhaust and intake fans going.  each are rated 265cfm and exchange the air in my 8x8x4 growroom 3-4 times per minute.  Noise is not a problem when the fans are mounted correctly.  the box and sound or fire insulation is a great idea. :hubba: _


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## ugmjfarmer (May 17, 2008)

PeaceKiller said:
			
		

> Hi ugmjfarmer,
> 
> I'm sure you will have the negative pressure, however it may not be enough and you may have heat build up. A cool tube or sealed reflector would be very helpful in keeping down heat.
> 
> Is this exhaust only for heat or for odor as well?



Heat and Odor. The Ballast I plan to use will be the starting point, just above the 400 HPS bulb. That way, the hotest point in the room has the air exhaust.


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## ugmjfarmer (May 17, 2008)

Ok scratch plans for Ebb n Flow. I'm going to build a Aero-DWC Bucket!:woohoo: 






















Plans are very simple, and the parts are very cheap. Should be good for 4 plants with huge huge root structures, which are going to be the biggest part of this thing.

I'll be picking up the parts Monday. This is going to be a long thread, as I plan to build/test the Bucket first, then prep the closet by sealing it with black/white vinyl and insulation, then purchase seeds and lights and the fan. As I stated earlier, carbon scrubbing will come soon but not immediately. My budget is pretty tight for expenditures like this.


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## The Hemp Goddess (May 17, 2008)

LOL--I have to chuckle at this:

"However I'm dead set on an ebb n flow (flood/drain) setup."

You seem to have things well planned out.  One thing I would encourage you to do now is to order some seeds.  They usually take 10 days-4 weeks depending on where you order from.  You can sprout and veg your seeds with a minimum of equipment.  Vegging plants can be quite happy under fluoros.  They can be vegging away, ready for you to put into flowering by the time the closet is ready.  You can buy things in the order that you will use them.  A carbon scrubber can be one of the last things you buy since it is generally only needed during the last half of flowering.  

One of the things I did discover about putting my closet together was that, no matter how much you read and studied, you were going to change your mind about some things as you got into it.  I think that you will be happy with the aero bucket (you might want to plan on having 2 of them).

I look forward to following your grow.


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## ugmjfarmer (May 17, 2008)

Gracias Goddess. Honestly it cant be that funny if plans change. I'm liking the fact that the Aero bucket will be a recycling system with no loss of nutrients to flooding medium. It will save me money in the long run on nutrients, and PH problems will be tamed down because of minimal use of the medium as well.

I think in a 1 Sq Meter area that 4 plants and 400w is enough with this kind of system. I'm going to go for a cheaper lamp at this point and spend more money on ventilation.


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## The Hemp Goddess (May 17, 2008)

Be advised--IMHO, your light is your most important piece of equipment.  I really believe that it is a mistake to scrimp on the lighting.  There is a direct connection between lumens and grams of bud.

I think in a .5 sq meter space (34 x 24 is 1/2 a sq meter) that 4 plants and a 400W  is enough, too.  I recommended 2 buckets because 4 plants are going to be really squished in one bucket and you have space for 2.  The roots will almost completely fill the bucket and grow around your aero sprayers.   With 4 plants in 2 buckets, the plants can spread out to better fill the space you have.  If you over or under nute or get root rot, it affects all your plants when in 1 bucket.

We here that give you advise are just trying to pass on what we have learned by experience in actual grows.  So, when someone suggests something different than what you were planning, it is with the best possible motives.


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