Hi, I would greatly appreciate some advice. I have enough money to buy an inline fan. I have a small grow tent (4x2x6). Is it better to exhaust my 400w HPS or Intake cold air. My room can stay cold with my AC unit. Also, if I exhaust, should I intake the heat right next to the light. I read that in-taking the heat can burn out the fan, and that air should be blown through the light. But my light reflector will not allow that.