Cool tube and ventilation Question

SO i have my cab built and my cooltube installed.
Should I pull cool air from outside this winter into the tube to cool the bulb and then back out? Would the cold break the bulb?
I'm trying to figure out how to manage my ventilation and the coming winter, so any experienced thoughts would eb much appreciated.

How big a light? How big of fan?

400w hps and a 6 inch duct fan blowing cool air through the tube duct.

If there's nothing else providing resistance you can probably get away with just cooling it with room temp air.

How are the temps inside the cabinet now? If you aren't having any heat troubles this time of the year, you should be fine.

You are blowing the cool air thru the tube? You should rig it so that it's sucking the hot air out and blowing it out the back of the cabinet(or side)

I was told that it might melt the fan blades which are plastic if I pull it out that way. Also the cab temps with a 4" duct fan pulling air out at the top and using the cool tube in it's current way are at about 80. I'm playing with the temps.. running it for about 2 hours to see what the heat would get too. I want to get it right before I fire up the hydro in about 2 weeks. I want to get it at least down to 75 consistently. I'm thinking I may need a better fan to pull air out.

I have been doing the same thing as you, getting it ready before the girls go in...
I have a Can Fan 4" with speedster speed control, Can Filter 9000 and a cool tube,
my temps are higher about 85 but im doing it in a dresser so small space and my ambient temps are hot right now 78 inside and 90 somethings outside
An option for you would be to suck air from in your grow room through your cool tube and out wherever you exhaust, and then I would suck the cold air in from outside and use that as air into your room.. Because the cool tube is more about getting the hot air out then actually cooling the light, and if your afraid of your room getting too cold you could maybe adjust how much air your exhaust?
Good luck and keep us posted on the battle!
Oh yeah and You shouldnt pull hot air through your inline fan because even if it doesn't melt the blades the fan uses the air going through it to cool itself too

Very helpful info thank you. I'm going to get a 4" Vortex from the hydro store. I think it's just easier and it will turn the air over every 10 seconds or so. I'm imagining that will keep the temps down and it comes with a 10 year warranty. I'll install and try that and vent the cooltube into the room and see how that goes. After that I'll set a timer to pull from the outside if it's not cool enough. I got a free carb booster from the hydro store.

you never said how cold it gets their in winter,if it is below freezing,no i would not.

Yes it does get well below freezing in the winter particularly at night. I think I'm just going to vent both outsides and when it gets really cold switch the cooltube to the inside to help with heating.

greenjumble said:

Yes it does get well below freezing in the winter particularly at night. I think I'm just going to vent both outsides and when it gets really cold switch the cooltube to the inside to help with heating.

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make sure you exhaust carbon scrubbed air outside and use the light to heat your home,you dont want them both on the same system.

below freeing! yikes

I'm going to be heating my home with my light too.

It's rough when it's below freeing. You can't go to the john when you want... they make you wear that itchy collar. Marijuana is all I have


I should post a pic of the cab. I'll do that later today. It's coming along nicely. I installed an exhaust fan which moves 171cfm and will clear the air every ten seconds or so. That should take care of the venting issues.