Cool Tube Grow Light Fan: Intake or exhaust?

Hey everyone, first post, but you'll probably be seeing more of me soon. I'll most likely be starting a closet grow journal real soon with some feminized Wonder Woman.

A simple question: I'm using a cool tube grow light. It will be connected to the outside air via two 6" flexi duct. I will be using a 6" inline fan to move air through it, but I'm not sure if its best to use it as an exhaust fan or an intake fan. This fan will not be hooked up to a carbon scrubber since no air from inside the grow room will be moving through it. I'm leaning towards having it as an exhaust fan.

Thanks

intake side on a cool tube will cool it better, but you can put after if you want...

Thanks for the feedback. Now that I think about it more it does seem a single fan would be most effective on the intake side.

Here is the fan I'll most likely get:
http://cgi.ebay.com/6-inch-INLINE-DUCT-FAN-exhaust-BOOSTER-blower-cool-air-/390127340450?cmd=ViewItem&pt=LH_DefaultDomain_0&hash=item5ad566cba2

Will this fan move enough air through ~9' of flexi duct to keep the bulb cool? Would adding a second fan on the exhaust end make a big difference?