Vortex Inline Fan to Cool Light

Can anyone point me to a site or a youtube on how to best put together a Vortex inline fan + ducting system to cool HPS light (in reflector) with duct apertures built into both sides of the reflector?

I'm not a handy-man.

I just browse ppl's journals and look at the pics. Pick and choose what looks and sounds best based on how the journal is going.

I just bought a 400w HPS/MH cooltubed light, with a 6" to 4" duct converter (the cooltube is 6" but my duct and vortex are 4"). Then just buy a couple of them duct clamps (something like these, you can grab em at Home Depot for like a buck a piece- http://www.novaflex.com/productcart/pc/viewPrd.asp?idproduct=734&idcategory=42 ).

Then all I did was clamp down the adapter to cooltube, clamped the duct to the adapter, and ran it up to my vortex. I'm not 100% sure if this is the RIGHT way to do it, but its been working for me so far, Ive been maintaining high 70 degree temps in a small closet grow. Hope this helps

the filter is the first thing in the line. drawing air into the filter then goes through the fan and pushes through the sealed hood,. keep all lines as straight as possible.,fans cool best by blowing through hoods and suckin through filer.

Medi 1 said:

the filter is the first thing in the line. drawing air into the filter then goes through the fan and pushes through the sealed hood,. keep all lines as straight as possible.,fans cool best by blowing through hoods and suckin through filer.

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A lot of people recommend:
filter->hood->fan->exhaust out tent/room
instead of:
filter->fan->hood->exhaust out tent/room

But I see people doing it both ways, so I imagine that for the most part, it's simply preference (or maybe sometimes logistics too). Either way, the filter does need to come first, and these fans are primarily designed to pull air.

its not realy preff..its fans are made to blow more than draw. so our filter life is longer. and cools better by blowing.

Golden reply. Thanks to all. Medi 1 and fourtwentychat differ in their opinion of the primary function of the fan, i.e. to pull or push air. Let me restrict this question to ventilation: the most efficient exchange of air. Quoting someone smarter than me, "A vent fan pulls air out of a room four times more efficiently than a fan is able to push it out" as stated by J. Cervantes, Horticulture . . . Medical . . . Bible, (2006), 317. My confusion is with the difference between a vent fan and a fan. Cervantes never clarifies it. He insinuates that the vent fan is part of a semi-closed system, situated toward the end of it, pulling.

If the above is accurate, it would support fourtwentychat's first option: [filter > hood > fan > exhaust port], which seems more logical than the alternative. I've read this section of the book one too many times. Everyone here's more experienced than me and I respect experience, so, Medi 1 if you wouldn't mind, if I got it wrong, where did I get it wrong? Are we agreed that regardless, the filter comes first in the ventilation circuit? Are there other opinions from other people?

At the risk of hijacking my own thread, are we agreed on some type of carbon scrubber inside the ventilation circuit, i.e. in-line? Are carbon scrubbers considered the best device to control the smell?

Thanks people, for taking the time to read and reply.

cerventes isnt a grower,,,he writes books and does it for money.

i am with a major competitor in this bizz( as a consultant not for pay) and a med patient and work in labs to test all this internet forum rumours or old data,. fans are built to blow bot suck or draw out of a room.

use one fan to blow filtered air in 24/7
use a second fan to suck air out when your light is on and when above 80deg.
use a carbon filter they are best suck threw the carbon filter to use more surface area for filtration
blowing threw them will make them clog faster and you cant see the dust build up.
and...
suck threw your lights too just keep them sealed good to prevent leakage of smell.
my logic to this is
exploding bulbs and fires and smoke and glass you want a negative air pressure to suck all that out
not blow it all on your crops or in your face when changing the bulb

using one fan will make the fan work harder
not having a intake and exhaust will make your fans useless
having the fans in the grow room makes more heat and if one fails it may smoke up your room

I grow with GOD

You want to pull the air through your light, Filter ----> Reflector -----> Fan ------> Exhaust out. The air coming out of the fan is heated by the fans motor and will add unnecessary heat. Inline fans are made to exhaust rooms.(i.e. pull air out)..dunno which fans Medi is talking about.

infinitescrog said:

You want to pull the air through your light, Filter ----> Reflector -----> Fan ------> Exhaust out. The air coming out of the fan is heated by the fans motor and will add unnecessary heat. Inline fans are made to exhaust rooms.(i.e. pull air out)..dunno which fans Medi is talking about.

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Now I'm curious about other feedback. I'm sure the difference is negligible in a short duct run setup on both sides, but given longer ducting requirements, is it best to position the fan at the end of the run (pulling everything) or not? I keep seeing conflicting reports (but mostly people seem to support the pull argument, which seems intuitive).

Medi, you mentioned that you run tests in a lab for this sort of thing. What tests have you run to determine that pushing air is the best approach?

Medi 1 said:

its not realy preff..its fans are made to blow more than draw. so our filter life is longer. and cools better by blowing.

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Im going to have to disagree; centrifugal fans are more efficient when sucking air out of the grow room. If you try to push the air all the way through the duct, you will have build ups at any bending, sending air backwards instead of forwards and creating unnecessary turbulence in the ducting. When you have a constant suction though, the air has a much harder time bouncing backwards against the air, thus creating a much more stable and efficient airflow.

I agree that sucking in the air from a HPS light might wear down the fan a little bit, but remember, most top of the line fans are MEANT to be used as high temp exhaust fans. Mine is rated for 200F.

You want to pull the air through your light, Filter ----> Reflector -----> Fan ------> Exhaust out. The air coming out of the fan is heated by the fans motor and will add unnecessary heat. Inline fans are made to exhaust rooms.

Click to expand...

The logic behind this is sound and I double checked the physics (God help me) and Cervantes is correct regarding the relative enhanced efficiency of pulling versus pushing air in a semi-closed ventilation circuit. And in the parlance of Newtonian physics, inefficiency equals heat - our nemesis. At this point, I'm going to have to agree with infinitescrog.

Clearly there are dissenting opinions on something that should be scientific. I'd very much like to hear other viewpoints.

Any other physicists about? How tight is the seal going from left to right (or whatever) across the hooded bulb from the intake ducting to the exhaust ducting?

I'm not a physicist beyond a year of college physics, I am a chemistry major

And I think a 600w HPS runs at like 185 degrees so thats well within the temperature limits of a decent inline fan.

infinitescrog, that's why I want to pull the coolest air (from the floor) across the HID. purplehazin talking about laminar flow plus Bernoulli's principle makes sense, which is why I still am unsure of where to put the filter in the circuit so that it doesn't compromise the speed and laminar flow of air across the bulb.

With filter first, inline fan last, doesn't that put a cork in the dryer hose? Fans and charcoal filters sold together have the filter attached to the fan. Behind the filter is the hood/bulb. On the other side of the hood/bulb is open ducting, going from a 6" radius to a 4" radius as it attaches to the ducting, trading velocity for pressure and ensuring that the potential energy is pulling cooler air from lower down in the room into the hose. Heck, I'm lost.

What do others do with a small closet garden?

I'd like to say " who cares" but it really matters in terms of ventilation.

For my closet grow I am pulling fresh air directly from outside the cab thru a fan and duct across the light and out thru the attic.

Then for cab ventilation I use a carbon inline filter mounted in the top that sucks air thru vents mounted in the bottom of the door covered with screen to keep out bugs and this exhausts into the attic also.

I like this method for keeping the air going across the light very cool since in my closet the cab is mounted in rarely gets more that 72 degrees.

HTH, Peace out

Seaghost, thanks for taking the time to reply. As long as you can keep your ducting organized and out of the way, yours sounds like the perfect solution. Shit, my office is 75 degrees and it's like 7 in the morning. I actually never thought of a dual system. The sound of two fans doesn't get to you? Is your cab vent fan inline or a squirrel cage (or all-in-one exhaust with activated charcoal)?

Again, thanks.

This question may get more replies elsewhere but I shall try here. If you are doing CFL lighting, is there any great reason to modify your ventilation circuit? Your temperature is lower and hence, the aroma will be a bit muted but it will be there, nonetheless.

Thoughts?