Vert Bulb Distances

**ActionHanks** · 04-10-2012, 08:06 PM

I see alot of people running bare CMH and HPS's in their vert set ups.
I understand that a cool tube would be the way to go, but how are some of these guys getting away with bare bulbs inches from plants? Rediculous cab airflow? Low ambient indoor temperatures? Lemme in on the secret, I'm tempted to try a vert for my next grow, and i dont feel like ordering a baking tube even though i probably will end up doing so.

**cowell** · 04-11-2012, 12:38 AM

heat rises... straight up. put a fan on the floor blowing up, and there's no heat right beside the bulb. haven't you seen the big box fan on the floor of all our grows?

**bboybojo** · 04-12-2012, 04:19 AM

have an 8 inch inline fan that i wasnt using anymore, chucked it on a milkcrate underneath the light; no heat issues.

**OGEvilgenius** · 04-13-2012, 07:14 PM

Originally Posted by cowell

heat rises... straight up. put a fan on the floor blowing up, and there's no heat right beside the bulb. haven't you seen the big box fan on the floor of all our grows?

I just use a little honeywell.

I think I paid 15 bucks for it.

**Stonetech** · 04-13-2012, 09:04 PM

I think the trick is to have a fan blowing up from below the light that matches the speed of your exhaust fan (which should be above the light). If the fan cooling the light is too fast it will just recirculate the air over the bulb, warming the ambient temperature in your space. But if it pushes air up slightly slower than the rate of the exhaust, it keeps the light cool (much like a cool tube) as well as help get the heat out of the space.

**glann** · 04-14-2012, 07:37 AM

you still get radiant heat from the bulbs. I have a 20 inch cyclone fan pointing straight up and much closer than 8-9 inches and you start climbing over 90. (ambient temps being 82-84)

**Phatman** · 04-18-2012, 02:17 PM

Originally Posted by Stonetech

I think the trick is to have a fan blowing up from below the light that matches the speed of your exhaust fan (which should be above the light). If the fan cooling the light is too fast it will just recirculate the air over the bulb, warming the ambient temperature in your space. But if it pushes air up slightly slower than the rate of the exhaust, it keeps the light cool (much like a cool tube) as well as help get the heat out of the space.

thats why he said slightly less than your out take stonetech

**Bob Smith** · 04-19-2012, 08:06 PM

I know I'm in the minority, but I much prefer using cooltubes over running bare bulbs.

Easier to cool and safer (IMO).

**ActionHanks** · 04-19-2012, 08:48 PM

Yeah I'm not seeing any disadvantages to using cool tubes, so that's probably going to be implemented. Cant decide if i want to dig around online for an actual tube, or construct one myself out of plexi