I have a small room with a 250W MH & a 250W HPS seperated by a light proof curtain. Have ducting from both lights to a 270CFM exaust fan. Lights have the glass lens to keep the heat in the reflector and away from the plants, which it does very well. I also have a co2 fermenter with 1/4" tubing coming from the co2 pump hanging over each plant individually..

My problem is, with my exaust fan on, it pulls the fresh air to cool the light from the louvers on the reflector from INSIDE the grow room. I do have the louvers pointed toward the ceiling of the grow room, so it isnt pulling the air from below the light right above the plants. Is the air being drawn into the light fixture to cool it down also pulling my co2 away from my plants, even though the air is being pulled in from ABOVE the light?

Should I bring in fresh air to cool my lights from OUTSIDE the grow room, so I can run the co2 while the exaust fan is on, leaving the room sealed without ventiliation. The exaust fan Must stay on constantly or the room will go over 100 degrees. When the lights are off, I have a 70CFM intake fan with 2 small oscillating fans running, which turn off when the lights come on.

I need to know if my current setup is wasting my co2, since the air sucking through the light is coming from INSIDE the room, or do I have to pull the air to cool the lights from outside the room. Pulling fresh air from outside the room will be a total pain in the ass, running ducting, cutting a hole in the wall for the ducting to pull the air in, disturbing the plants while I work on the room. 3 pics attatched of the room.

Attached Images

	111.bmp (18.1 KB, 17 views)
	222.bmp (18.1 KB, 6 views)
	333.bmp (18.1 KB, 3 views)