Cooltube, blow or suck?

303

Well-Known Member
Can someone set this straight? I thought it was most logical to have cool air blown from outside, or another room through the light reflector and out of the room. Others suggest they suck the hot air out, this way you can also use in conjunction with a carbon filter if you wish. Which is it? I've never had a air-cooled reflector and just got one, and am confused which is the proper more efficient way. Thanks for input in advance..
:confused:
 
I use my fan to suck the air but you can use it to push.I use it to suck because i have 1 end open also exhausting the growroom.
 

303

Well-Known Member
I use my fan to suck the air but you can use it to push.I use it to suck because i have 1 end open also exhausting the growroom.
OKay so either way works it sounds like. Just didn't want to do it the wrong way. My first grow I had the fan blowing into the carbon filter for a week or so until someone on RIU pointed out to me I needed to suck air thru.. LOL. Stoner..
 

frenetic420

Well-Known Member
i have ducting pulling air from outside and blowing through the light. with the fan in front of the light blowing cool air through the hood then out the grow room.
There are 2 advantages to this. Your blowing cooler air through the fan by having it blow air through the light. And you have cool air blowing over the bulb.

Either one will work and fans are made to run at high temps. But i think my method is best in my opinion. Since there is less stress on the bulb and the fan.
 

303

Well-Known Member
i have ducting pulling air from outside and blowing through the light. with the fan in front of the light blowing cool air through the hood then out the grow room.
There are 2 advantages to this. Your blowing cooler air through the fan by having it blow air through the light. And you have cool air blowing over the bulb.

Either one will work and fans are made to run at high temps. But i think my method is best in my opinion. Since there is less stress on the bulb and the fan.
That was my plan, blow cold air in from outside.. Sucking hot air out doesn't seem to be most effective without some serious CFMs
 

303

Well-Known Member
Gotta be careful when it goes below 30 degrees blowing into a hot bulb, could shatter....??? where I live it freezes at night already..
 

mrmadcow

Well-Known Member
I wouldn't worry about the cold air as long as it is constant,most streetlights are HPS or MH.they works well below 0
as to suck or blow,most fans are more efficient when sucking but another thought is odor.if you are drawing fresh air from outside throu the light and out of your growroom,a fan sucking will also suck air(and smell) from any leaks in the tubing so some air will get out of the room without passing through your filter but a fan blowing air through the vents and light will blow air out any leaks & into the grow so it can be filtered.all in all,I would seal ducting well & set fan to suck air unless smell is a VERY BIG concern.
 

ympb

Member
as to suck or blow,most fans are more efficient when sucking but another thought is odor.if you are drawing fresh air from outside throu the light and out of your growroom,a fan sucking will also suck air(and smell) from any leaks in the tubing so some air will get out of the room without passing through your filter but a fan blowing air through the vents and light will blow air out any leaks & into the grow so it can be filtered.all in all,I would seal ducting well & set fan to suck air unless smell is a VERY BIG concern.
I started out pulling air through my lights but the leaks caused my garage to smell bad. I say push the air through, may not be as efficient but my odor problem dissapeared when i switched mine around.
 

303

Well-Known Member
I wouldn't worry about the cold air as long as it is constant,most streetlights are HPS or MH.they works well below 0
as to suck or blow,most fans are more efficient when sucking but another thought is odor.if you are drawing fresh air from outside throu the light and out of your growroom,a fan sucking will also suck air(and smell) from any leaks in the tubing so some air will get out of the room without passing through your filter but a fan blowing air through the vents and light will blow air out any leaks & into the grow so it can be filtered.all in all,I would seal ducting well & set fan to suck air unless smell is a VERY BIG concern.
Nicely put, +Rep..
Guess I'll try it both ways and see.. I feel like the fan doesn't have much "suck" power, it blows really hard though..?
 

whynot

Well-Known Member
I just did a DIY Cool Tube for my 150w and it is just a light vent, cabinet has it's own passive intake/fan exhaust. So I did mine intake>fan>light>exhaust, straight across and it seems to be pretty god damn SWEET!! It's on a test run and i'll check it in a little bit and see how well it's working. But so far, very pleased. I was worried about sucking the hot air through the fan as from what i've read it's not good for them.
 

whynot

Well-Known Member
My fan is to the right of the bulb, blowing left. Straight in one side, straight out the other. Is this correct? The glass is not hot to the touch, with about 1" between the bulb and the glass all the way around. It tops out at 83 degrees 6" below the glass now.

IMG_2280.jpg
 
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nickfury510

Well-Known Member
My fan is to the right of the bulb, blowing left. Straight in one side, straight out the other. Is this correct? The glass is not hot to the touch, with about 1" between the bulb and the glass all the way around. It tops out at 83 degrees 6" below the glass now.

View attachment 1163934
if you switched it around and pulled the air across the bulb your canopy temp will drop lower. an inline fan moves air with more velocity on the pull than on the push. it is also less drag on the fan motor to pull air through 4' of ducting than it takes to push it
 

whynot

Well-Known Member
The air won't be too hot on the fan motor doing it that way? Just worried about the fan failing due to heat. They say not to expose the fan motor to more than 140 degrees F. Should the fan be a certain distance from the bulb?
 
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