hi there any help would be great,ive got a h6ft w3.4ft d2.8ft box and ive got a 400w growlux sodium bulb with reflecter the ballast is on the outside of my box,an extractor fan sucking 85m3 at the top and at the bottom there is a slightly bigger inlet hole at the bottom that gets air from the outside and an 10inch fan blowing the top of the 2 plants which my friend gave me yesterday and he has started flowering them for about two weeks so i put them on 12/12,the problem is that the temp inside the box is reaching 40c it does not feel that hot.please if you have any info/solutions i would be gratefull as ive just built the box and im new to all this,my mate gave me theese plants until my seeds get big enough to put in there thank you and please help
are the leaves begining to curl? if so, i recomend another small fan pushing air through your inlet. I have about a 3 inch gap at the bottom of my closet door. i often see my leaves curl if im not running a fan directly on that gap. Also, to help with heat issues, I have my lights off noon to six(grow) and 8am-8pm(bloom). keeping the temp down during the hotest part of the day. I hope that helps, T.Bug
Sup man, How we doin? just get some big ass fans in there. They do sell namebrand air extractor fans at home improvement stores. If your short on cash just get those vortex fans they do wonders even though they are really small. Ok all lates.. PEace, JOnAS
What is the ambient temp of the intake air? Any way to cool the intake air down more? Adding a fan at the intake could be helpful, but my first recommendation would be to get a stronger exhaust fan. Typical rule of thumb is that you want an exhaust fan rated at three time the volume of your grow area. Your volume is 57 cu ft and your fan is rated at only 85, I would shoot for 150+. If you buy a new exhaust fan use that 85 to draw in at the intake.
this is my first post and i hope i can help. i have a small area i am using as well and getting the temps just right are very hard. i have just bought a system called Growtronix that has made my growing a lot easier. with Growtronix i am able to control my temp through my computer. i have a temp senor in my room and a box with my light and fan plugged in to it. if my room is too hot my computer turns on the fan to cool it down and when the temp goes down the fan will turn off. it also works as a light timer too. you should look into it man, it has helped me a lot!!!!! good luck with everything
Your rule of the tumb (correct or not) lacks a critical component. Power! Or does that rule of the tumb go together with rule of the index finger for an average Wattage/sq. ft.?
The rule of thumb is a minimum of three times the volume of the box for the rated amount of air the fan will move per minute. Whatever amount of power the fan consumes is...well, not irrelevant, but it is built into the mechanics of the fan and ultimately is expressed in the cfm. If a fan is rated at 150cfm then whatever the power it consumes to achieve that is what it is. But power is not missing from the equation because the equation is about matching the fan's volume capacity to the volume capacity of the space. To put it another way, if the fan had more power it would be reflected in a higher cfm. None of this has anything to do with watts per sq foot, which is a lighting rule of thumb. And of course, all of these "rules of thumb" are just general notions to see if you are in the right ballpark, none are hard-and-fast rules, none will guarantee a successful grow, etc. They are good for telling you if you are way off base. For example, with regard to the poster of this thread it seems clear to me that he is not moving enough air to control his temps. I don't know if 150cfm will correct his temps, but I know 85cfm is not enough.
I agree with toasty. My box is 39 Cu. Ft. and I have a large computer fan rated to 100 CFM sucking the hot air out at the top. I'm maintaining 27C temps.... Hey
I agree with toasty. My box is 39 Cu. Ft. and I have a large computer fan rated to 100 CFM sucking the hot air out at the top. I'm maintaining 27C temps.... Hey guys, will you give me a green card? I had some losers blast me with red cards and I don't think they were warranted. Thanks bros! I'm not a total newb anymore and I have respect for the forum.
LOL. 1x2 I agree withs and 1 green flag. All of them misunderstand me. The power I am refering too is the power usage of the lights in the box. Not the fans power usage you dummy! This because 90% or more of the power that goes into the lamps comes out as heat and not light. And I agree with you that his setup needs much more then 85 CFM.
My mama didn't raise no dummy! The "power" really isn't what is needed to be measured, it is the amount of heat that needs to be vented whether generated from the light or ambient temp. From that standpoint my previous answer was deficient. there is no rule of thumb -- the one I was quoting is really for ventiation requirements only, so should be considered the minimum. Controlling heat is a matter of four variables: - The temp of intake air - The amount of heat radiated in and into the space (lights, walls, etc) - The size of the space to be cooled - The volume of air moved though and out of the room There is no magic answer to reducing a given amount of heat in a certain space, it is playing around with all of these variables.
I had the same problem of temp. adding an active intake is really helping to reduce high temp. I also noticed that humidity reduces temperature so I just keep the level of humidity high. as it evaporates, the temp raises( i dont know if you understand my english!!!!haha). good luck men