How many fans would you suggest?

**Finalfaze** · 10-12-2007, 07:35 PM

Hey all, im new and just setting up my first grow. I was wondering if anyone knows how many fans ill need to adequetly keep air flow in a 2x4x6 ft room?

Ive got a 600wHPS light and will be looking to grow 3 plants. Iwant to have an air intake at the bottom and outtake at the top but have no idea on the amount of fans?

There 8cm computer ones by the way and ive just read the 'making a DIY carbon filter' article and will be wanting one of these too.

BUT wont it construct air flow therefore needing more outlet fans?

And would placing the fans on top of each other be more efficient than side by side?

Hope ive been clear and you can all shed some light!!

**silk** · 10-12-2007, 07:52 PM

I use 1 465cfm exhaust fan for a 4x4x8 room which has 2 passive intakes. I also have an oscillating fan inside to blow on the plants. I don't know th CFM rating of your computer fans but I do know it would be helpful if you can refresh the air every 5 minutes.

Good luck!

**Finalfaze** · 10-12-2007, 08:02 PM

Thanks for the advice! anyone else?

**daddychrisg** · 10-12-2007, 08:14 PM

Figure out the square feet of your room, and get the appropriate fan that will replace your air every 5 min....Golden rule...

**Finalfaze** · 10-12-2007, 08:24 PM

Thats the exact question im asking.... How many fans would it take....

**silk** · 10-12-2007, 09:13 PM

Originally Posted by Finalfaze

Thats the exact question im asking.... How many fans would it take....

Well the answer could be 1. But you were talking about computer fans. How many of those I don't know. Do you get it now? If I plugged my fan into your setup it would be more than enough. It's more than enough for me.

**Galvatron** · 10-12-2007, 09:16 PM

figure out your sq footage and then look at the fans cfm ratings. sq ft = length x width. cfm = cubic feet per minute.

try this, its for greenhouses though but it should work:

ACF Greenhouse Exhaust Fans & CFM Calculator

**Finalfaze** · 10-12-2007, 09:20 PM

thanks guys

**daddychrisg** · 10-12-2007, 11:47 PM

Hey finalfaze, I would have done the calculations for you, but I know I always learn more by figuring out those kind of things better by calculating the numbers myself...Gl with your grow! I would just pick up a 4" Vortex fan and get it done right! If you are going to put in a carbon filter later on, I would definitely put a good fan in there.... It is easy to put in a dimmer switch so that you can control the speed of the fan...Ok, gl and when you have more questions about this you can PM me if you would like...