Cooltube/Vent question, 400W HPS question

First of all I would just like to say thanks to all of you on here, I was successful on my first grow with just some basic CFLs and soil but I'm lookin to step it up now. I couldn't have done it without the help of you veterans that really know your shit... Thank you!

For my new grow:
Home-made box and drip system.
Box is 4'x4'x6' with a simple bucket-drip ring setup.
It is essentially a homemade version of the stand alone waterfarm unit with a drip ring above a hydroton grow chamber.

Now I am on HTGsupply and getting ready to order:
400W HPS with Euro Reflector for air cooling.

Now my question, if I get this in-line fan/carbon filter combo and hook it up so it is sucking air from one end of the Euro reflector through the carbon filter and out above my closet (into my attic), can I leave other end of the hood exposed?

This will allow the fan to not only cool the light but also vent the box... I am just wondering if it is bad for me be sucking all that air from the box right past the light, because I see alot of people have 2 exhaust systems. One for their light and one for their cab. Just an FYI, I have a passive intake system setup... My growbox has a 6" round hole in the bottom corner where I will be attaching few feet of 6" dryer ducting so the light will not escape but the air can get in.

So my question is... is it imperitive that I have 2 venting systems and separate the air going to/from the light from the rest of the cab, or can I get away with using 1 fan and exhausting all the hot air from the light/cab at once. My main concern here is heat because I have never grown with a HPS bulb before. I am also new to hydro in general but I don't forsee any issues with that...

I already have all the supplies I think I will need such as a PH tester, nutes, and airstone for when the roots grow past the hydroton into the water.

Any help is really appreciated!!

I am currently using the one that cost 185 and I would recommend that. You are looking at a 4" filter, most ducting and the euro reflector is 6" and for an extra 40 bucks you get a lot more air flow 424 cfs and a bigger scrubber which will last you longer. The 4" to 6" conversion piece is probably like 5-6 bucks anyway. I'd go big for the fan you wont regret it.

I currently have it rigged to ducting and pulling air off an open faced reflector. I just have the ducting right below the bulb so it sucks the heat off the bulb and in the room as well, it then blows it out the other side of the wall and out of the room through the scrubber, and into a room where you wouldnt even know (except for the noise, those fans are loud).

I am about to be upgrading my open faced 400 to two 400's in the Euro reflector. If I was you I would also consider upgrading the reflector. I am going for the Euro because I am in a 4x5 room and will have two of them casting a perfect light shadow, but with just one your light shadow may come up a little short. The Super Nova would be perfect for you. It is 99.00 dollars.


But fundamentally I have the same question- because I am going to be linking my two 400's in euros together and i would like to leave the far end open to pull air in and diminish drag from the ducting. I have a fresh air intake pulling near the euro's blowing air into the room. Linking them would mean I'd need a new intake...

I think your situation is easier than mine, you should have no problem using a euro reflector with an open end (barring you upgrade to the larger fan, its the only one I can speak on since I own it). I think it would help pull off heat that rises from any radient heat that escapes the glass.

But make sure you still have good intakes.

OB Cron Kenobi said:

I am currently using the one that cost 185 and I would recommend that. You are looking at a 4" filter, most ducting and the euro reflector is 6" and for an extra 40 bucks you get a lot more air flow 424 cfs and a bigger scrubber which will last you longer. The 4" to 6" conversion piece is probably like 5-6 bucks anyway. I'd go big for the fan you wont regret it.

I currently have it rigged to ducting and pulling air off an open faced reflector. I just have the ducting right below the bulb so it sucks the heat off the bulb and in the room as well, it then blows it out the other side of the wall and out of the room through the scrubber, and into a room where you wouldnt even know (except for the noise, those fans are loud).

I am about to be upgrading my open faced 400 to two 400's in the Euro reflector. If I was you I would also consider upgrading the reflector. I am going for the Euro because I am in a 4x5 room and will have two of them casting a perfect light shadow, but with just one your light shadow may come up a little short. The Super Nova would be perfect for you. It is 99.00 dollars.


But fundamentally I have the same question- because I am going to be linking my two 400's in euros together and i would like to leave the far end open to pull air in and diminish drag from the ducting. I have a fresh air intake pulling near the euro's blowing air into the room. Linking them would mean I'd need a new intake...

I think your situation is easier than mine, you should have no problem using a euro reflector with an open end (barring you upgrade to the larger fan, its the only one I can speak on since I own it). I think it would help pull off heat that rises from any radient heat that escapes the glass.

But make sure you still have good intakes.

Click to expand...

I was thinking about getting that 6" fan/filter combo, I just wasn't sure it was necessary, but I think I'll just splurge for it, knowing it will probably be worth it in the long run.

I was also considering putting a smaller piece of ducting on the opposite side of the Euro hood and just running it to the top of the box, this way it wouldn't be completely open and I could vent all the hot air from the top of the box as well as the heat from the light, my main question is still the same though. I heard it was a bad idea to be pulling alot of moist air from the box right past the light, which is what i would be doing. This method allows for only 1 fan which is what I am trying to accomplish in order to minimize cost. A single 6" fan/filter is still cheaper than two 4" fans and 1 filter

Thanks for your help man

I'm happy you've found rollitup to be useful to you as I have as well : best wishes and may your harvest be all you want it to be ...