Wondering what size of fan to use for intake and exhaust?

I was wondering what size of intake and exhaust fan to use to keep a 4x4x8 with a 600 watt hps? About to start my first grow room. Thanks for help!

I use 6" fans for both intake and exhaust. Just remember when choosing fan sizes to make sure to keep the pressure inside the box equal. I've always used the same fan for my intake as I do with my exhaust.

thanks for the advice. I just purchased two 50cfm ventilation fan, would that work?

N.541 said:

thanks for the advice. I just purchased two 50cfm ventilation fan, would that work?

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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 cool

i got 50 cfm and they worked surprisngly well for so cheap

I was think about buying a 6inch fan or should I get two more 50cfm fans as the intake and use the other two 50cfm ventilation fans which I mentioned in earliers reply as the exhaust? But I will try it tomorrow with the two 50cfm fans.

Is a 50cfm squirrel cage fan is sufficient for a closet about 2Wx4Lx10H?

CrazyIMA said:

Is a 50cfm squirrel cage fan is sufficient for a closet about 2Wx4Lx10H?

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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.