# 6 inch Intake and Exhaust; Is This Enough?



## IllusionalFate (May 22, 2008)

I have mostly everything for my upcoming grow ready besides ventilation. Once the two 6 inch inline duct fans arrive, I'll be putting one through the ceiling with a winding flexible duct to the outside (to ensure no light can enter), and the intake fan will be constructed the same way, pulling air from the adjacent room into the grow room through a flexible duct.

I will be running a 600 watt HPS in a 5'x2'x7.7' (LxWxH) space. The fans are rated at 250 cfm.

I have never grown using HID lighting before so I'm not quite sure how much ventilation I need, but taking into account the small area, a 6 inch intake and exhaust seems like it should cool the room plenty. Even with the heat of a 600w HPS, those size fans seem like they would do the trick.

These are the fans I will be installing:
http://www.htgsupply.com/viewproduct.asp?productID=46447

Do you guys think this should be adequate ventilation or will I likely need more to keep the temperatures in check at all times?


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## OdorDoc (May 22, 2008)

You should find another fan - these are NOT 250 cfm.  They are rated at 250 cfm MAX BOOST.  They are duct booster fans and the max boost rating is the point at which the fan starts to hinder flow instead of increasing it.  The actual free flow cfm is closer to 100 cfm and real world performance may be much lower depending on the static pressure in your setup. 

Any reputable company will state FREE FLOW CFM and not MAX BOOSTED CFM, which is completely meaningless for this type of application.

See the link below for an example of this type of fan from a seller that provides both the free flow and max boost cfm for an example:

http://www.hvacsolutionsdirect.com/catalog/SUNCOURT-4-THRU-12-SINGLE-SPEED-INDUCTORreg-DUCT-BOOSTER-FANS-p-36.html


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## SweetSoca (May 23, 2008)

i was thinking of buying that same fan, except i have a 400w hps, not 600. do you think that fan would be adequate for a light that size? or is it still too wimpy?


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## smokybear (May 23, 2008)

Maybe another one and you should be good. Just my thoughts. Better too much than not enough. Take care and be safe.


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## Timmyjg6 (May 23, 2008)

http://htgsupply.com/products.asp?categoryID=7&subcategoryID=39


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## Kupunakane (May 23, 2008)

Yo Ho IllusionalFate,
  Sounds like your getting a grip on the fans, and as far as the size of the duct work, your in really good shape there. Six inch is more than adequate.
 I look foreward to what you will have when your setting up is all done. 
  I have always advocated taking your time , and doing the job the right way, sounds like your right in the groove partner. 

smoke in peace
KingKahuuna


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## Eggman (May 25, 2008)

Cooltube it and pipe out 6 inches  you'll never have to worry about heat or air flow. You can also put a dimmer switch on an industrial fan :hubba: just groud it right so it doesn't scream. you'll see if you don't ground it


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## parkingjoe (May 25, 2008)

yes downside of cooltubes is the crap light spread which is candle like imho

youre getting 2 x 6" fans so first id just have one pulling air into room via venting fitted into rooms wall and check to see what temps are like with fan pulling air into room 24/7 if temps are too high then one of two things you could do have air pulled from roof space aka outside house or do same setup with both fans pulling air into room passively and its just a case of tweaking timer to adjust on/off for correct temps.

pkj


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