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450 watts too much?

S

sman

Member
I have roughly 450 watts in my rubbermaid stacked box and i think it might be too much heat. I have a 120mm computer fan for exhaust and the lights are separated by Plexiglas but the temp is pretty high.

box dimensions
Capacity:
35 Gal / 132 L
Dimensions:
32 1/2" L x 19 3/4" W x 18 5/8" H X2 because i have 2 stacked

the temp gauge i have in the box says its 100F with 16% but it does not feel that hot when i put my arm in there

**here is my design thread http://www.icmag.com/ic/showthread.php?t=192790**
 
O

oldtree

Member
That's alot of light for such a small place. When I grew with rubbermaid tubs I was using half the wattage. You're temps should be around 70 to 80 degrees. If you are commited to your lighting then you need a larger fan or one that moves more cfm's
 
S

sman

Member
oldtree said:
That's alot of light for such a small place. When I grew with rubbermaid tubs I was using half the wattage. You're temps should be around 70 to 80 degrees. If you are commited to your lighting then you need a larger fan or one that moves more cfm's
Click to expand...

so sould i

1. take out a couple lights and see if the temp goes down.
2. make another intake in the lights chamber (neg pressure box)
3. add another fan and intake, leave the lights
 
M

microbox

Member
i wouldnt use a intake fan unless you wanted positive pressure , i'd take out a few lights

do you a intake at the bottom? how big is it? it should be 2-3 times larger than the exhaust. if you dont have a exhaust in the plant are, than you'll need one there too.
 
durka_durka420

durka_durka420

Member
are you using cfl or what dude you never said and my guess is your using cfls and looking at the light equivalency rating which is totally wrong you look at what the actual wattage of the bulb is....and you need some more intake and exhaust if your at 100f get it to 75-85f
 
S

sman

Member
microbox said:
i wouldnt use a intake fan unless you wanted positive pressure , i'd take out a few lights

do you a intake at the bottom? how big is it? it should be 2-3 times larger than the exhaust. if you dont have a exhaust in the plant are, than you'll need one there too.
Click to expand...

i do not use any intake fans.

I have (2) 5'' pvc intake elbows (on one each side) in the bottom tub (grow chamber) and (2) 4'' dryer duct exhausts connecting to a scrubber that has a 120mm exaust fan.

and in the lights chamber i have (1) 5'' pvc intake elbow and a 120mm exhaust fan.
(this is not mine but i have the same exact design https://www.icmag.com/gallery/data/500/12309252W_Tub_p3.JPG)

*i do not know the cmf on the fans nor do i know how to measure cmf. it does not say on the fan what it is.

**but in my lights chamber my exaust is not 2-3 times larger then the intake. maybe that is my problem?

***also, this thread is probably supposed to go in "Growroom Designs & Equipment". Sorry for misplacing
:smoke out:
 
S

sman

Member
durka_durka420 said:
are you using cfl or what dude you never said and my guess is your using cfls and looking at the light equivalency rating which is totally wrong you look at what the actual wattage of the bulb is....and you need some more intake and exhaust if your at 100f get it to 75-85f
Click to expand...

i have (14) 27 watt cfl's and (2) 47watt cfl's = 470 something
 
E

Emph

Member
Pc fans list their cfms on the back of the box, where they have more specific, technical listings for their specifications.
 
E

Emph

Member
In that case, measure them. They're probably normal PC fans, either 80mm or 120cm. Google 120cm PC fan CFM and I'm sure you can get a rough estimate to how much they move... But no real point, 'cuz like scurred said... lol If it's too hot, less lights or more fans. :p
 
M

microbox

Member
you might want to look into a "real" fan, not a pc one, cfls run hotter because the ballast is connected to the bulb, so I would guess 450watts of cfls is something like a 500 or 600 remote ballasted hid
 
C

CFL_Grow

damn 500 bux on rubbermaids..

With that kind of cash just throw a 250w HPS in there...
 
I

IwannatokeNbone

Member
makes no sense to run clf to that wattage over n h.i.d. i would of just ran a 150hps with two 42 watt 6400 cfls . i would of started horizontal and budded vertically, heat wouldnt be an issue any fan couldnt take care of, what are u shotting for a 100 watts a sqaure foot?
 
I

IwannatokeNbone

Member
microbox said:
you might want to look into a "real" fan, not a pc one, cfls run hotter because the ballast is connected to the bulb, so I would guess 450watts of cfls is something like a 500 or 600 remote ballasted hid
Click to expand...


great point, people dont get this, just go to target an by a 15 dollar little fan, cut a whole on both sides, blow the hot air right out that thing, problem solved, dont mess around with little comp fans doing next nadda, not with that kind of heat output. what made u go so crazy with the watts, on top of the fact that they have no penetration and are unmovable at the very top of your box, u could of just got a pl-l and got ten thousand lumens for a 110 watts and kept your girls n inch or two from the bulbs with no heat problem? the reflective material also isnt needed, after an a few inches from the lights the light is so weak that bouncing of the walls aint gonna matter to anyting but your eye, i would of gone pl-l perhaps even three units, top n on both sides with the sides one covered with a piece of plastic so the plants didnt touch the bulbs, at that wattage and hid even at 150-250 would of been easier to cool n yeilded better as well as cost u less initially, if u could id take the lights back n get diff ones.
 
S

sman

Member
well it's probably too late to turn back now I just got super excited with red's box and built mine twice as big but with the same vent design as his. so i should have also doubled my vent-ness. O well learn from da mistakes.

thanks everyone for the advice!

:wallbash:
 
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