40 degrees Celsius is grow tent!! Help

Hey all,

I have a 3x3x6 ft grow tent laid on it's side in a roof space. It is bloody hot up there and gets to 40c when outside temp is only 25c! I have a 250 cfm extraction with carbon filter attached. Passive intake which draws from a cooler area via ducting. I am only running a 200 watt cfl during veg. I have a small fan blowing over the plants. What the hell should I do?? More small fans? Another inline? I want to avoid Aircon. Any help would be appreciated (ps I'm a noob!)
Cheers

Where are you directing the air being blown out of the tent? Is the exist hole towards the top or the bottom?

The intake fan is probably sucking hot air into your tent from the attic. This wont cool anything. If you can draw air from a cooler spot youll have better luck, even outside.

Thanks. The intake is pulling air from a cooler area around 2 metres from the exit hole which is on the bottom of the tent. The air going out of the tent is going directly into the attic outside the tent.. Kind of answered my own question I think haha. Would additional oscillating fans help any if I redirected the passive intake. The area is always going to be hot in summer as we get temps up to 46c.

Im not sure if im reading your post correctly and you may already know this but... hot air rises.. if you want to move the hot air from the grow tent, you must have the vent exit holes toward the top.. so the hot air is quickly removed and not just blowing around in the tent.. hope this helps a little. good luck

have your intake from in the house or out side leading to a bottom corner of your tent and a couple of fans for air circulation

A 250 cfm fan hooked to a carbon filter and what sounds like at least 7-8 ft of duct work is probably only moving less than 100cfm due to the static pressure in the duct work and restriction of the carbon filter. Sounds like you need a bigger fan and more intake. Also make sure you are not creating a strong negative pressure in your tent. This will cause hot air from the attic to infiltrate your tent through small leaks at the seams, zippers ect........

If it gets 46C you wont be able to grow without a cool air source or AC. Attic is probably just not doable during that time.

You cant grow in the roof space, put the tent somewhere else or what you'll produce wont be worth it its too hot even at 28.

Thanks all! I have installed another inline and will now look for an aircon! Unfortunately this is the only stealth spot I have available at this point so I have to make it work! At least winter should be better?!?! Thanks again I appreciate the help

Alexander Supertramp said:

A 250 cfm fan hooked to a carbon filter and what sounds like at least 7-8 ft of duct work is probably only moving less than 100cfm due to the static pressure in the duct work and restriction of the carbon filter. Sounds like you need a bigger fan and more intake. Also make sure you are not creating a strong negative pressure in your tent. This will cause hot air from the attic to infiltrate your tent through small leaks at the seams, zippers ect........

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Thanks for your help mate. I have installed another inline fan. The sides of the tent are "sucking in" pretty severely. Is this what you mean by negative pressure?

If you really want to make this work you need first to supply the proper amount of fresh air to the inside of your tent a 250 cfm fan will require a 10 inch round duct from your cool air source to your tent ,then you need to take tha new fan you have hang it in the attic it self high as possible and duct that to the outddoors some how The other option is to buy what is called a attic ventelater fan, it gets cut in to the roof from the outside, it will also have a thermostat that can be adjusted to come on at dif temps, this would be the proper way to remove the heat from your attic ,they are not expensive, but unless you have experience in cutting in to roofs ,I would recomend you call a roofer to install , this will pull more air through your soffet moving more outside air to your attic that will lead in a ambient temp to drop.

Try installing a Whirlie Bird on your roof (One of those round spinny vent things..) They work awesome for venting attic heat.. and wont draw any heat to your grow

Jay3Lee said:

Try installing a Whirlie Bird on your roof (One of those round spinny vent things..) They work awesome for venting attic heat.. and wont draw any heat to your grow

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You are a mind reader my friend... I just bought two today! I just have to work out how to put it on the roof as it's 6 metres high!

Can you move to the basement instead of the attic?
Basement temps are usually more stable as well as cooler.

Might want to invest in a mini air conditioner. (not cheap)