650 Watts in a GL80

Greetings all:

I have the GL80 tent and will be using a Sun System 7 dual spectrum reflector for part of my lighting needs. For an initial test run I stuck my 175W MH bulb on one end and my 250W HPS on the other, all connected to a 4" inline blower to help with cooling. The temps in the tent hovered right around 75* which isn't too shabby.

I am really contemplating on bumping it up to a 250W MH/400W HPS for a total of 650 watts. I also plan on running C02, which will be controlled by a Sentinel CHHC-1 greenhouse controller, and an additional 4" fan for active air intake. Should I run a 6" inline blower instead of the 4" for the reflector, keeping in mind that it will be pulling air through a carbon scrubber as well?

THX

[David G.]

I'm pretty sure that 650 watts of light in a completely sealed GL80 is going to create too much heat, regardless of which fan you use. It may be possible if you eliminate the CO2 and use the fan to both cool the lights and exhaust the room, especially if the intake air is cool enough. Another option that would work is to utilize the Ice Box heat exchanger, but you would probably need a chiller (or at least a large water storage tank), which may make it cost prohibitive.