4x4x8=128 cubic feet you want at minimum a 5 min air exchange if you use hids bump that up to every minuet. so your 50 cfm will change your air every 2and a haf min or so put your lights up chk the temp make sure its coolthanks for the advice. I just purchased two 50cfm ventilation fan, would that work?
work out the volume of your grow area, 2x4x10 = 80, so a 50 cubic feet per minute fan will cycle the air in less than 2 mins. Bear in mind that any ducting/ filters etc in your vent system will reduce your actual cfm somewhat. depending on your lighting that fan may be more or less than you need.Is a 50cfm squirrel cage fan is sufficient for a closet about 2Wx4Lx10H?