F ftw2012 The end is near! Joined Dec 23, 2005 Messages 400 Reaction score 56 Jan 4, 2006 #1 hey Ya'll. im a first time grower and also a first post. my question is i have a 600 watt hps in a room thats about 50 cubic feet. about how many cfm of exhaust do i need to keep the room from over heating? Thanks in advance for any help!