I need help figuring out what kind of exhaust fans to run. I have a 20x7x11 room so I need close to 300 CFM for my grow space. I was wondering if anyone had any suggestions as to any exhaust fans that run very QUIET and close to 300 CFM or sufficient enough for my grow area? I plan on running 2 1000w HPS's in my flowering space and 1 MH possibly in the other area and was also wondering if my single 8" vortex inline fan w/ ducting would be sufficient enough to vent all 3? Thanks.
The 8" has a higher CFM rating than you would normally need, but if you are venting three lights, and it sounds like youll have a little ways to vent the air, I would recommend it. The vortex fans are relatively quiet. Can Fan Max fans can run a little noisy but, if you have a room that large, are you really worried about the noise a fan will make? All of the specs on the fan can be found here: Vortex VTX800 8" 747 CFM Powerfan
Will I need any sort of ventilation exhaust for the grow room itself in addition to the inline i have for the hoods?
You should definitely have an exhaust fan and an intake system. You could get away with just using an exhaust fan blowing old air out, which in turn will force new air in. If you would like, PM me with your grow room specs and I will help you configure something!