Can't Keep Temps below 90-100F

I built a grow box in a dresser (3.5' H, 2.5' L, 1.5' W).

The lighting is with a CFL fixture I built out of PVC pipe.
It consists of 10 23W CFLs

I have 2 x 120mM 12volt fans, 1 intake on the bottom and 1 exhaust near the middle back of the box (can't put it at top, be a DEAD give away to the grow boxes existence), and an oscillating fan inside.

They are still babies (grown from seed), so its hard to say how they are reacting to these temps, but most of them are drooping pretty bad (they are growing very fast however, with almost NO lateral growth between each set of new leaves).

With the lights on and dresser closed temps approach 100F. They are typically stable at 92F though, which is ... way too high.

When the dresser is COMPLETELY open the temps dip to 82F which is still WAY too high for me, esp. with the box completely open.

I thought these CFL's wouldn't create any heat problems, but apparently they do (its a good thing I didn't put my 400W MH in there).

Ambient room temperature is 65F, thats a delta of over 25F, so I don't know whats going wrong.

Any advice would be greatly appreciated.

cfls shouldn't produce that much heat im running 8 of them and my temp doesn't get below 70 or above 82 there is no reason for the heat i only use a 3inch computer fan to keep the heat down and that works well

you have serious problems if even 3 fans still aint keeping the room cool

id say reduce the number of ur cfls from 10 to 4 because 10 in a space of that your using well over the amount of lights but keep the 4 of the light 3/4" away from the plants
see how that goes

guitarguy10 said:

Any advice would be greatly appreciated.

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a major upgrade to your ventilation or switch to LED lights.
CFLs are not as eficient as HID so they will produce a lot of heat.
Check out this dude's LED grow-->
https://www.rollitup.org/grow-journals/419673-first-grow-300-watt-led.html

That doesn't sound right, especially when your actual room temp is 65F.
My whole room is 85F right now but it's been getting to be 95F-100F on my temperature meter.

Do you have the fan blowing the lights? I keep one below my T5 fixture blowing heat up and away from the plants.
Plus when I get up I open up the closet, the dresser and then turn on my fan that blows fresh air in from the window.

I'm getting sick of having plants in my room (I have a lot of different plants) so I might turn the guest bedroom into a plant lab this summer.
should be a fun little project.

The oscillating fan is blowing on the lights constantly (its on its side ... not oscillating ). The intake blows partly over the lights, the exhaust is way higher in the box atm It is very bizarre lol

As for LED growing, why would I throw away all the money I spent on creating this CFL fixture to spend even more on LED lol, I don't have much money, I don't grow for profit (I grow for medicine .. for myself heh)

i needs a few bits of info

how many plants?
you space it that in inch/mm/ft

I understand ur heat problem. I had heat issues with just 4 cfls in a 1'x1'x18" space.

If you get a duct booster it will take care of the job. You dont need one of those super high powered vortex fans for your dresser, but a duct booster will do.

http://www.homedepot.com/buy/building-materials/heating-venting-cooling/inductor/6-in-inline-duct-booster-fan-62750.html

EDIT: The duct booster doesnt come with a wall jack plug. I just cut the end of my cellphone charger and wired it up took 2 minutes.

You need better ventilation. Your space is too big for those little computer fans. A while back I was running a box of a similar size with a 200W cfl. I had 3 4" intake holes in the back at the bottom and three 4" holes at the top with computer fans exhausting from those. I had temps of 8deg over ambient which was ok.

The thing to keep in mind is that all computer fans aren't created equal. Some are really shitty fans. I did my research on the ones I was using and got fans intended to exhaust the small cramped area of stereo equipment. Those fans have a higher static pressure rating than some others. I bought these http://www.ncixus.com/products/26744/DFS123812H-3000/Scythe/

they rock as far as case fans go. High static pressure, high cfm and reasonable price...

Xiphos said:

I understand ur heat problem. I had heat issues with just 4 cfls in a 1'x1'x18" space.

If you get a duct booster it will take care of the job. You dont need one of those super high powered vortex fans for your dresser, but a duct booster will do.

http://www.homedepot.com/buy/building-materials/heating-venting-cooling/inductor/6-in-inline-duct-booster-fan-62750.html

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The problem with those online duct fans from HD is that they have basically 0 static pressure. They suck cause they don't suck...

pixelpusher said:

The problem with those online duct fans from HD is that they have basically 0 static pressure. They suck cause they don't suck...

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Go invent a better windmill or something then.. fuckin dork. You really think a 120mm fan is gonna do shit? They're for coolin computers but not a 13 cubic foot grow space with 10 lights..

Nitro1990 said:

i needs a few bits of info
how many plants?
you space it that in inch/mm/ft

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8 but 6 will be going outside leaving only 2 to be grown to ... fruition in the dresser
Feet as I stated in my first post of 3.5' H, 2.5'L, 1.5'W (I hate imperial but that seems to be what everyone wants to hear)

pixelpusher said:

You need better ventilation. Your space is too big for those little computer fans. A while back I was running a box of a similar size with a 200W cfl. I had 3 4" intake holes in the back at the bottom and three 4" holes at the top with computer fans exhausting from those. I had temps of 8deg over ambient which was ok.

The thing to keep in mind is that all computer fans aren't created equal. Some are really shitty fans. I did my research on the ones I was using and got fans intended to exhaust the small cramped area of stereo equipment. Those fans have a higher static pressure rating than some others. I bought these http://www.ncixus.com/products/26744/DFS123812H-3000/Scythe/

3x2x1 is too big?

The fans I am using are equal, as they are fans I purchased back in my overclocking hayday. They are QUALITY panaflo fans, they push a lot of air and generate a lot of static pressure (I know cuz the back middle fan blows the cover (which weighs like 15 pounds) right off the front of the dresser when its blowing in, and sucks the panda plastic HARD when its blowing out (exaust). I may look into those scythe fans because of their price, but they will not replace these panaflo's heh.

Xiphos said:

I understand ur heat problem. I had heat issues with just 4 cfls in a 1'x1'x18" space.

If you get a duct booster it will take care of the job. You dont need one of those super high powered vortex fans for your dresser, but a duct booster will do.

http://www.homedepot.com/buy/building-materials/heating-venting-cooling/inductor/6-in-inline-duct-booster-fan-62750.html
How much CFM do they push? They look ultra wimpy, if I were to go this route at all I think I would just buy an inline fan (though I would need ducting in my ventilation, which I have none of atm).

I'm glad to see my post has sparked so much .... passion ... lol. NO HATE !

Thanks for all your advice, will try some things (like making the intake a second exaust and the current intake 'port' a passive intake).

Still frustrating and confusing though !!

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you really think that piece of shit HD inline duct fan is going to do shit you fucking cunt?! go back to fucking your mom and stop giving folks brain dead advice. I mean seriously if you don't know what the fuck you're talking about just shut the fuck up.

Ok you're all cunts that fuck your mothers, back to the topic.

How many plants do you have in this box? is this a veg box only?
It would probably be 100x easier to figure out why it's getting so hot if you had some pictures.

guitarguy10 said:

As for LED growing, why would I throw away all the money I spent on creating this CFL fixture to spend even more on LED lol,)

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you ain't growin' shit at those temperatures, figure it out yerself then, jerk.

You need 3 of those pc fans (high CFM rating) for exhaust probably one more intake and fans blowing in between the bulbs and the tops. The exhaust needs to be as high as possible and definitley above the lights. Take your temp readings from the tops of the plants.

Get a fan rated for at least 40 cfm for exhaust, if you have enough exhaust it will pull in cool air. Since you are handy with electricial rethink your light setup less lights higher watts. Two or three 54w or one 75w cfl, 65K for veg and 27K for flower. Remember CFM is the rating for moving air.

lol why so much hate?

Anyways ...

ganjames,

As I said to someone else who asked, there are 8 babies in there (in beer cups), 6 of them will be getting planted outside once they look healthy/vigor enough, 2 will remain in the dresser until harvest.

It will be for both veg and bloom, its solely veg right now as all of my 8 plants were grown from seed and will be a while off before I flower them. Today is day 16 since I put them in paper towel.

I would love to have posted pics and would have definitely done so if I owned a camera or any device capable of taking pictures, which I don't (no I DO NOT own a cell phone).

Frmrboi,

I know i'm not growing at these temps, hence why I asked for the advice of the wise. Your advice, no offense, was tantamount to telling someone with car troubles to drive their car off a bridge and go buy a Mustang.

I can't (and won't) just throw away the few hundred dollars i've already invested into CFLs when I know they are supposed to be running much cooler, just to buy a much more expensive technology. If I were made of money i'd be full out aeroponics setup growing in a rented space with HIDs, not a dresser.

JL209,

These fans are rated to push about 90CFM each, they aren't 'typical PC fans', they are high performance 120mM fans I bought a few years back when I had the full blown watercooled CPU/GPU/Northbridge and required GOOD intake and exhaust into my PC case.

I know what CFM (and ACH) stand for ... did I say they stood for something other then air flow dynamics before?

I wouldn't call myself handy with electrical, more like 'barely capable', lol but thanks for the compliment I wanted to use higher wattage lights, but unfortunately, of the like 20-30 stores I went to none had anything higher then 43W and those bulbs were $20 each ! (I live in Canada so ... the availability of some products is limited). These stores were all in Toronto, so if I were gonna find em anywhere, thats where heh (I would buy em online but customs is too much ).

If you or anyone knows a retailer in Canada who sells higher wattage CFL bulbs for ... not crazy amount of money, I would be grateful. I built the fixture with enough clearance that it can hold the largest dimension E26 socket bulb I could find the dimensions for (on 1000bulbs.com)

Currently there are 10 23W 6500K bulbs in there for veg. I will switch them out with 2700K bulbs when I go to flower (hopefully my plants don't die before then !)

Mrdank007,

3 90CFM exhaust? Should I not just use the 260CFM squirrel cage fan I have then? I didn't use it in the first place because I figured a 260CFM fan in a 13 cubic foot space, which would be 1200 ACH would .... implode the dresser, or at the very least create so much negative pressuire as to kill the plants?

With so many fans, I imagine odor control will become much more of a problem (i'm not too concerned with it atm since they are all babies with no smell)

I'm sorry for the confusion, just getting a WIDE range of answers lol

I appreciate all your responses, and sorry if my answers seem rude or whatever, just trying to answer all of your many responses (for which I am extremely grateful !) with as much detail as I can.

I'm also sorry for the rude flame war between Xiphos and Pixelpusher . I created this thread with the aim of hopefully solving my own problems, while at the same time answering them for anyone else who might be as unfortunate as I am atm with this crap lol

O, I raised the lights to be completely above the intake (vs. half above it before) and the temps dropped at least 5F from just that alone, so ... positive thinking.

i was just having this overheating problem myself, thankfully im in an unfinished basement and my air-supply duct was running right over my tent. i popped a whole in that bitch, ran a 4" duct to the tent. and cranked the AC, now i am living in a cool comfortable 72 degrees and my plants are back down to 78 or so

Too many bad posts to comment on >.< Great job trying to keep up the good vibes guitarguy.

LED post looked like a spammer haha

Inline fans are fine! It, like any other axial fan, has a hard time creating negative pressure because of just that, they are axial fans. You can't say a cheap, $25 6" inline fan that is rated at 450CFM is shit compared to X axial fan rated <450CFM. Most axial fans have the same basic design flaw in terms of creating negative pressure, they are axial. My inline fan for my 1000W cooltubes is just the 6" one and my tubes are barely warm to the touch. You could hold the cool tube for an hour and be annoyed that you touched damn thing for an hour.

Also, since computer fans are axial it's just comparing cfm to cfm. Squirrel cage fans aren't ideal to create negative pressure but work much better than axial fans. Just sub-par to centrifugal fans. (I know this is a cost issue so the squirrel cage shall have to do.) When worried about smell that's when it should be used with a type of carbon scrubber DIY for cheapness ^_^

Honestly with your fans I'm not sure why it's getting so hot in there. Could it be fan placements? I'd need to see the grow to see what's going on.

MasterS said:

Too many bad posts to comment on >.< Great job trying to keep up the good vibes guitarguy.

LED post looked like a spammer haha

Inline fans are fine! It, like any other axial fan, has a hard time creating negative pressure because of just that, they are axial fans. You can't say a cheap, $25 6" inline fan that is rated at 450CFM is shit compared to X axial fan rated <450CFM. Most axial fans have the same basic design flaw in terms of creating negative pressure, they are axial. My inline fan for my 1000W cooltubes is just the 6" one and my tubes are barely warm to the touch. You could hold the cool tube for an hour and be annoyed that you touched damn thing for an hour.

Also, since computer fans are axial it's just comparing cfm to cfm. Squirrel cage fans aren't ideal to create negative pressure but work much better than axial fans. Just sub-par to centrifugal fans. (I know this is a cost issue so the squirrel cage shall have to do.) When worried about smell that's when it should be used with a type of carbon scrubber DIY for cheapness ^_^

Honestly with your fans I'm not sure why it's getting so hot in there. Could it be fan placements? I'd need to see the grow to see what's going on.

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Thanks MasterS. I managed to borrow someone's camera (I don't own my own, nor a cell phone), and took a few pics, 3 of drooping plants, 2 of what I consider the 'healthy' plants (notice how short they are?), and one of the fixture/box. I can take more if you'd like just ask me what you want a pic taken of I am sorry for the bad quality, I did everything I could, but its an older camera

O yeah, these plants are on Day 16 from seed (day 1 being the moment I put them in paper towel)