cool tube ? extraction

[Gruffy]

why do u need a filter before the cooltube ? just curios as i wasnt gonna bother lol :P

Most fans you will find for this application do better sucking or pulling air than they do blowing or pushing. Inlines are the best as they are more efficient, quieter, etc., and also pull air better. This means you will want the fan to be at the very end of the exhaust side, pulling air through a filter, then your cooltube, then ducting (as little as possible), and then to the fan and exhausted.

air flow---->filter--->cooltube-------------------------------------->fan-->exhausted

Gruffy Reviewed by Gruffy on 02-19-2008. cool tube ? extraction Hey guys n gals .. I am gonna buy a cool tube for my setup .. what fan would i need to sufficiently cool a 400w hps light ? and would the fan be pushing the hot air out of the tube or sucking it ..in other words does the fan go before or after the light .. im having a dumb moment and i reckon its extraction hence why they are called extraction fans lol i just need someone to verify lol regards :) hope someone answers :) Rating: 5

[Opie Yutts]

Most fans you will find for this application do better sucking or pulling air than they do blowing or pushing.

I've heard this from several people. Does anyone know the physics behind this?

Also, I'm pretty sure 2 fans would be better than 1, especially in longer runs. If I had a bigger one and a smaller one, would it go like this?

intake>smaller fan>cool tube>carbon scrubber>bigger fan>exhaust

Or I guess, depending on how closely matched the two fans are, it might be better to just leave out the smallest one. Anyone? And where's the cut off point? At what % difference would it be best to just leave it out. If it can't keep up, it would just hinder air flow. Would the two fans need to be the same? And why are those sheep up in the trees?

[Gruffy]

i was thinking

intake>cool tube>fan>exhaust

im only a hobby grower and i have 3 plants i would have thought one decent fan would be sufficient to withdraw enough hot air too keep my 400w light cool enough.

i think we need someone with some experience to comment here possibly some pics of their setup ? :stoned:

[Opie Yutts]

What we need is an HVAC guy, or else we need to look up the formulas on the web and do some calculations. Naaa, too much work.

[FourOneNine]

Obviously, it would be better suited to have the carbon scrubber at the complete end.

(passive intake)-->Cooltube-->Fan-->Carbon Scrubber--> AIR

Construction should vary mostly on CFM of the fan.

I run a 400W MH, on A OPEN reflector. 6inch Duct connect to fan then scrubber, I get 82F.. But my fan is 400+ CFM so I dont need any take holes, air gets pulled from cracks around the cab. My friends seldom wonder why Smoke gets sucked into my closet.

[gainesvillegreen]

Obviously, it would be better suited to have the carbon scrubber at the complete end.

(passive intake)-->Cooltube-->Fan-->Carbon Scrubber--> AIR

Construction should vary mostly on CFM of the fan.

I run a 400W MH, on A OPEN reflector. 6inch Duct connect to fan then scrubber, I get 82F.. But my fan is 400+ CFM so I dont need any take holes, air gets pulled from cracks around the cab. My friends seldom wonder why Smoke gets sucked into my closet.

I would like to know the reason why "obviously, it would be better to have the carbon scrubber at the complete end".

Most setups I have ever seen had the scrubber-->light-->ducting-->fan-->exhaust. Because fans suck better than blow, forcing a fan to blow against the filter will diminish the volume of air flowing.

I'm guessing you could find supporting info either way, but this page talks about it at the bottom.

[xcrispi]

I tried cooling my cooltubes both ways . Pushing and Pulling air through them . I went as far as checking surface temps of the glass w/ a hand held laser temp gun too. They were significantly cooler w/ air being pulled through them .

I also tried Opies theroy - 1 pushing and 1 pulling and the 1 pushing air was a restriction = temps went up .

We now have 3 -1000w. hps. inline cooled by a 630 cfm hurricane blower now and the 10 by 12 foot room doesn't get over 82 degrees . Here's a pic. w/ just 2000w .
Peace
Crispi :jointsmile:

[CashandPrizes]

im gettin ready to upgrade to cool tube hoods.

this might be a dumb question but all i have to do is plumb them into my main exhuast fan?

for some reason i thought there was a little fan built into the end of the hood were the duct starts?

[Opie Yutts]

I would like to know the reason why "obviously, it would be better to have the carbon scrubber at the complete end".

I was wondering the same thing.

[Opie Yutts]

forcing a fan to blow against the filter will diminish the volume of air flowing.

Yeah but so does sucking through a filter. Theoretically, wouldn't it take the same amount of force to go through something one way as it does the other, not counting diodes and stuff?