How to Vent Marijuana Grow Room Visit More info at http Exhausting and Venting your Marijuana Grow Room can and will keep your Grow Room cool and with Fresh Air Flowing. We show you here how to cool the Grow Room for less than a $100.00 and without having to buy an expensive portable A/C Unit. The video shows how I cooled my Marijuana Grow Room with a 365 CFM Blower, Some Flex Duct and My Buildings Sewer Drain Pipe. How To Grow Cannabis bringing you the information you need