Hey, just a thought are you going to use the inline fan to extract just the heat of the bulb or keep the one end open to draw out also the growing area heat? You didn't mention the grow space so I am guessing a whole room or? Also handy thread about Fans and fresh air/cooling that you may like. http://boards.cannabis.com/growroom-...ml#post1381660

I use a 400w air cooled hood in both of my grow logs but thats not even close to the amount of air your going to want to move depending on your garden.