Inline Fan for Daystar AC Hood / Reflector

First time grower here. I just bought a new DayStar AC (air cooled) Hood / Reflector. I need to get a dedicated inline fan to cool it (in addition to my grow room 8" inline exhaust fan). The flanges on the DayStar are 6" in diameter.

So, what CFM fan should I get to dedicate to cooling the DayStar? My grow room 8" inline exhaust fan is rated at 636 CFM.

Thanks in advance.
 
Top