# Tent Fans and Ventilation



## maineharvest (Jan 21, 2011)

Im starting a new grow in my 4x4x7 tent and want some input on setting up fans and ventilation.  
Right now Im running one 400 hps and temps are getting up to 90f.  I plan to add another 400 hps in a few weeks at the start of flower and I cant imagine what the temp will be then.  Right now I have two six inch rotating fans blowing on the plants and one four inch fan blowing air out a ventilation hole the top of the tent.  
The two lamps I am using both have the butterfly type reflector so I cant really ventilate the hoods.  
Im curious to how other tent growers setup their fans in the tent.  I want to maximize every inch of my tent and do a  SOG style grow.  I will be doing two clones in each five gallon bucket and will be adding some plants that I am starting from seed(feminized) and putting right under 12/12 from the start.


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## nouvellechef (Jan 21, 2011)

You really need aircooled hoods in a tent. So I really dont have a answer. My only answer of compnsating with AC, would not make sense. Because in the long run, ordering 2 new hoods would pay for itself vs the cost of killowatt hour from a AC keeping it cool. Thats if outside temps are ok. Beyone that, AC is your answer with a combo of aircooled hoods. Hope that helps.


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## maineharvest (Jan 21, 2011)

Thanks Nouvellechef.  So your thinking aircooled hoods and then run ducting from the light to the hole in the top of the tent with a fan?  

Any pics of peoples setups would be great.


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## nouvellechef (Jan 21, 2011)

I dont have pic anymore of the tent. But hamster just posted some. Yep. Hoods go inline and insulated R6 ducting from depot. Keep it short and tight. Fan goes at end of line pulling air thru the hoods and exhausting outside.

Ok maybe he didnt of tent. But you get the idea. Short and tight! Get Pro-grip pulleys to raise and lower hoods. Use level to make them nice and even.


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## maineharvest (Jan 21, 2011)

Sounds pretty easy.  Thanks for the help.


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## nouvellechef (Jan 21, 2011)

No prob.


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## maineharvest (Jan 21, 2011)

Looks like Im going to have to drop another $300 on some hoods and ventilation.  Adding upgrades to my grow op year after year is costing me more money than my car does.


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## nouvellechef (Jan 21, 2011)

Haha. It will pay for itself though in many ways. For one, no compensation of AC via killowatt hours and second, no or at least less heat issues cause you can move air thru it quickly and efficently. Thirdly, no more posting here about 90 degree heat. Thats just too hot inside. Even for CO2. GL


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## Jericho (Jan 21, 2011)

Why not instead of buying another 400w you buy a 600w with a hood. That way you will only have one light during flowering and less too cool. 600w get hot but i doubt as hot as 2x400w. That also means less ducting. 

A 600w puts out about 90k lumens where a 2x 400w put out about 100-120k lumens. You only need 80k in that size tent.


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## lordhighlama (Jan 21, 2011)

maineharvest said:
			
		

> Thanks Nouvellechef. So your thinking aircooled hoods and then run ducting from the light to the hole in the top of the tent with a fan?
> 
> Any pics of peoples setups would be great.


 
maineharvest I posted these shortly before the forum went down, hope they help some.

View attachment flower%20tent1.jpg

*Inside of flower tent... Filter>Hood>Fan>Exhaust*

View attachment veg%20tent1.jpg

*Inside of Veg tent... Intake>Outlet to Flower*

View attachment venting.jpg

*Outside of tents showing duct from veg to flower, and exhaust from flower out the back*

View attachment venting2.jpg

*Intake and exhaust holes, both have screens on opposite end of wall*

View attachment venting4.jpg

*Crude Sketch.*


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## maineharvest (Jan 21, 2011)

Jericho said:
			
		

> Why not instead of buying another 400w you buy a 600w with a hood. That way you will only have one light during flowering and less too cool. 600w get hot but i doubt as hot as 2x400w. That also means less ducting.
> 
> A 600w puts out about 90k lumens where a 2x 400w put out about 100-120k lumens. You only need 80k in that size tent.




Right now I own 3 400hps lamps so I'd rather use what I have instead of going out and buying a fourth hid.    You know what Im sayin?


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## maineharvest (Jan 21, 2011)

Wow Lama!  There should be a whole section here dedicated to tents and that should be a sticky.  That breaks it down into simple directions and with pictures too!!  

Whats the math on figuring out what size fan I need to vent a 4x4x7 area?


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## maineharvest (Jan 21, 2011)

How did you hang that fan Lama?


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## Jericho (Jan 21, 2011)

You have 112 cubic feet there (4x4x7) So times that by how ever many times you want to exchange the air and thats the fan you need. Most people choose to change air 3-5 times a minute. 

If you already have the 400w then use them. Thought you was going to go buy another 400.


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## lordhighlama (Jan 21, 2011)

maineharvest said:
			
		

> How did you hang that fan Lama?


 
You cant see it in the picture but it has a bracket mounted to the fan that is then secured to one of the braces running across the top of the tent.

jericho got you sorted on the other question.


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## maineharvest (Jan 21, 2011)

Ok Thanks


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## hero4u2b (Feb 20, 2011)

HI everyone.. I am about to order 3 items from HTG supplys first is a 400 watt HID/HPS lamp I will want an enclosed unit with glass covering the bulb I was told..with 6 inch vent cooling thru the lamp I cannot run my duct out a window nor an attic so I will be attaching duct pulling from my Light and out into a carbon filter that will be strapped over head.  Does this sound good to everyone?  Any advice will be appreciated. Thanks yall


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## lordhighlama (Feb 21, 2011)

where will your intake air be coming from?  Your going to have to bring in fresh air from somewhere.


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## bho_expertz (Feb 22, 2011)

I suggest cooltubes ... two lamps with two cooltubes one end the carbon filter on the other end the extractor ... For closets/tents the cooltubes are great.


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## sickbiker (Mar 5, 2011)

maineharvest said:
			
		

> Im starting a new grow in my 4x4x7 tent and want some input on setting up fans and ventilation.
> Right now Im running one 400 hps and temps are getting up to 90f.  I plan to add another 400 hps in a few weeks at the start of flower and I cant imagine what the temp will be then.  Right now I have two six inch rotating fans blowing on the plants and one four inch fan blowing air out a ventilation hole the top of the tent.
> The two lamps I am using both have the butterfly type reflector so I cant really ventilate the hoods.
> Im curious to how other tent growers setup their fans in the tent.  I want to maximize every inch of my tent and do a  SOG style grow.  I will be doing two clones in each five gallon bucket and will be adding some plants that I am starting from seed(feminized) and putting right under 12/12 from the start.


I have a 2"7x2"7x5"7 tent with a 400w vented hood and i could hold the temp at 70 if i wanted i keep it at 80 and my fan kicks on about every 15 to 20 mins and only runs for about 5 mins at a time i will take some pics of my setup and post them so u can see if u want


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