There is in fact a complicated formula to figuring it out, I didn't care to learn it. The short answer it would seem is over 400cfm will do the trick for a 600 watt. So that's a 6" vortex style fan with probably as much as 100' of duct. A quick search revealed the following: 6" Fan - 79$ I believe I will order something along this line. Be careful that you don't get a bad 6" fan. Some of the ones I see listed on ebay range anywhere from 250 cfm to 450. So make sure you get one that goes at least 400cfm I recon.
Prodaytrader Reviewed by Prodaytrader on . New Setup - Ventalation Advice I've been growing with mixed results for a while now, and I have decided to upgrade from my micro-grow (150w HPS scrog - 2 plants per DWC 5 gal bucket) to a 600w HPS (1 plant per DWC 5 gal bucket). I know I need to upgrade my ventalation situation. I have the following questions: 1. If I use an air-cooled light, what size blower would I need to ensure that the heat from the 600w is exhausted from the room? 2. If I use another fan to extract residual heat and stinky air, can I just use a Rating: 5