What's the REAL difference between booster fans and exhaust fans?


Oct 3, 2016
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Hey buds. Hopefully some of y'all can help me out here. When I bought my text and related gear, I bought what seemed to be to be a decent fan. One of these:


Since then, I've had issues controlling the temps in my tent at times, and have learned that what I bought is not the right kind of fan and that it's apparently less powerful than "proper" inline exhaust fans because the CFM listings for inline booster fans (what I bought) are meant to signify how much air they can move that's *already* moving, vs. how much stagnant air they can move out of a grow room or tent (which is what the CFM listing on an inline exhaust fan denotes).

What I want to know, is - can anyone point me towards actual test results or videos or whatever that show the differences? I'm curious to see how close to the listed CFM capabilities each type of fan comes, and if there's really that much of a difference.

Thanks! :thumbsup:
Have you checked out "inline fans", that's what you need and is what you run with a carbon filter. They are far more powerful than the little fan that you posted. Every manufacturer lists their CFM. It depends on the size tent you are in for needs. Also, be sure that the CFM is larger for the carbon filter than that of the inline fan. The come in a wide variety of prices. I have utilized Vortex fans and Phresh carbon filters for many years. They are in the higher price category. Just do some research on inline fans and carbon filters and you will understand more.