I currently have a grow box and I was wonder which pc fan to place as my exhaust and my intake. I have two 3 inch pc fans and four 2 inch pc fans. I already know that you put the exhaust with the bigger fan to take out all the hot air but then how big should be the intake fan be????????? Does anyone know the best combination using these fans???????????? I also have a clip fan but that is only to circulate the air within my grow box. Thank you for your responses and I hope to hear many of them.
:h ump:

i'm jsut a newbie but i think you have it backwards. the smaller fan can be used for the exhaust because warm air is less dense and therefore can be moved more easily. the larger fan should be used for the air intake because cooler air is more dense and more difficult to move. just my $.02. good luck

__________________
Fifer
"It's better to remain silent and thought o fool than speak and remove all doubt" A. Lincoln

It's best to have a little neg pressure so you want your exhaust to move slightly more cfm then the intake.

__________________
Hospitals have patience... I DON'T!!!

Also, i just found out that the two bigger fans are 120 mm that can move out 48 cubic feet per meter and the four 80mm fans can move out 32.5 cubic feet per meter. Now what is the best setup i can produce with these fans in a 3 x 1 x 3 feet area?????????????????????????????????????????????? ?????????????????????????

CFM is cubic feet per minute and those fans are over rated. Try the four small ones as exhaust for a total of 130 cfm, and the two bigger ones as intake for a total of 96 cfm.

__________________
Hospitals have patience... I DON'T!!!

OR you could buy a few of these like I did:

Vantec Tornado Fan 80mm

84.1 CFM for an 80mm fan! Simply awesome, if you don't mind the sound