What's it going to take to cool this 400W HPS

Hi I have a 400W HPS Im really wanting to use.

I have one central air vent that is pretty strong (gets to around 70 easily enough). Atm it is vented directly into my tent. In a 3x3x6 grow tent (and regular room tempts around 85) would intake/exhaust fans be enough to cool the tent?

How would you set this up?

So basically Inline fan pulling air from outside ->ducting-> 400W in cooltube ->ducting -> another inline fan pulling the cooltube air out


What type of CFM power am I going to need for these fans?

Hi dude you could run your ducting :-


Window > Carbon Filter > Ducting > in-line fan (Pulling air out) > Cool-tube/air-cooled reflector and just have a passive intake.

or

Window > Ducting > in-line fan > (Pulling air out) > cool-tube/Air cooled reflector > ducting > Carbon Filter and passive intakes

or if the air outside is cooler than the air in your room..

INTAKE :- Odor Sok > Window > Ducting (to intake @ bottom) then separatley.......
OUTTAKE:- Cool-tube/Reflector > Ducting > In-line fan (sucking out) > Ducting > Carbon Filter (in your room/ not in the grow tent etc..) , You can draw in cool air from outside and exhaust 'INTO' your room/house via a Carbon Filter, just leave a few windows ajar for air exchange and job done..

I do this, and it works great.... except I replace the window.. with an AC, but it still works great

If your only running a 250 or a 400 you should even be able to get away with pull air in and exhausting from/to the same room, as long as you can leave a window or 2 slightly open


a 400+ CFM in-line fan is to be recommended, what size cool tube/ reflector ducts are you using ?? - STELTHY

So much of your question depends on variables such as length of run from light to final exhaust,how many bends or turns in the pipe,weather its flex pipe or straight pipe ect.

Also when you say regular room temp is 85 degrees are you refering to the temp inside the tent or ambient temps in the room the tent is located in,85 degrees is too hot if its the temp inside the tent,you want temps in the grow area to be from 70 to 75,anything higher & growth slows,above 80 degrees buds start to loosen up & at 85 & above all buds loosen up with the smaller buds turning into wispy popcorn type buds.

You should have the intake side of the bent bringing in air from outside the grow area unless the intake is attached to a carbon filter,if i was growing in a tent this is how i would vent the light & cool the tent.

I would use a carbon filter attached to the intake side of the light,then have the exhaust running outside the tent to a 6 or 8 inch fan pulling air from the light & tent at the same time,the exhaust comming from the fan would be directed out the nearest window.

When you use air cooled lights even the strongest fan cant stop all the heat from the bulb,radient heat from the bulb & glass on the hood/tube will allways release radient heat into the grow,this is why i reccomend pulling air from the tent to cool the light.

Setting up like this where air is being sucked out of the tent creates a vaccume effect that keeps all smell inside the tent ,the air being sucked from the tent will draw in air from the surrounding room outside the tent & keep a negative pressure on the tent keeping smell inside.

Use atleast a 6 inch centrifugal fan,those lil duct booster fans are no match for a centrifugal fan of the same cfm rating,centrifugal fans pull much more air when a load is put on them,connecting to filters creates load & all regular duct fans loose more than half cfm when loaded,centrifugal fans only loose about 10% when a load is put on them,you can get a 6 inch centrifugal fan from HTG shipped to your door under $100 & their fans are just as good as any fan on the market,infact all centrifugal fans are made by 1 of 2 manufacturers with the exact same motor so by the cheapest costing centrifugal fan from htg.

Using outside air is definitely out of the question. It's around 110 outside.

To be able to use the AC vent and to vent outside the window would require ducting running around my whole apartment room which I don't want to do. I was hoping since its a 400W light I might be able to just pull rooom temp air through it to cool but since the room (outside) the temps are around 85 it might heat up (this outside room) too quickly.

I saw some pretty dank bud grown with CFLS so I think I'm just going to try that.

use a 4" inline fan 170-200 cfm. just hook the ducting up to the hood andd exhaust into another room in the house. as long as the ambient temp in the room is around 75 and you are exhausting thee light out of the room you should be fine.

ran into the same issue, had two 400w hps with air cooled hoods. Wound up switching to leds. More expensive up front, but with a three year warranty and energy savings it balances out in the long run (esp with bulb replacement costs over three years). Now running 690w of power as opposed to well over 1000w with the cfl side lights. Temp in my room is a cool 74 degrees. Pics in the journal in my signature if you're interested in seeing what I've done with them. When I purchased I thought I could always flip them on ebay if they were shit, recoup my investment and get my two hps lights back. I will be keeping my current led set up.

what LED do you recommend?

I run 2 systems. 1 exhaust, and 1 for the cool tubes.

The exhaust: Carbon filter>Ducting>Inline fan>ducting>Attic
Cool Tube system: Attic>ducting>Cooltube>ducting>Cooltube>ducting>Inline Fan>ducting>Attic ....pretty much closed off from the grow area so I don't have to tax it with a filter.

My exhaust shuts off and stays off for a bit while my co2 system runs. If my cooltubes were apart of the exhaust system, the glass would get pretty hot when the system shut down for co2 injection.

The best leds I've personally used are from HydronpicsHut.com. I have two of their 180 Pro-Grows and 1 PG 250. I also have a 100w UFO from Grow LED Hydro and two shitty 90w ufos from Ebay (one brand unknown, the other from LedWholesalers - they're both jokes and only used as side lighting). Pro-Grow or GLH will give you good results, I know this to be true. If you do wind up buying leds make sure they're covered by a substantial warranty. There is a ton of bullshit panels and ufos out there giving this tech a bad rap. There is no substitute for proper research. Whichever route you go (venting vs. different lighting) best of luck man.