How do I know which fan to get?

[ddeder]

I need to put an exhaust fan in the back of my computer. I see there are high, medium and low RPM exhaust fans. How do I know which speed to get? Also, is 80MM pretty standard in most cases?

Thanks.

 

[ddeder]

bump

 

[Citadel535]

My Antec case has built in "snaps" for 80mm fans. I put four in there and it is not bad at all in terms of noise. I would suggest to mainly want to look at CFM (cubic feet per minute) which is how much air it moves a minute. Over 30 should be fine. I don't think RPM really is a significant factor compared to airflow.

There are basically three types of fans: Dual Ball-Bearing, Ball-Bearing, and Sleeve-Bearing.

Dual Ball-Bearing spin on little metal balls and have the longest lifespan and also tend to be louder.
Ball-Bearing is a combination of metal balls and a cone sleeve that has less life than dual but is quieter.
Sleeve bearing rides on a cone sleeve and is the quietest but will also fail sooner(I am actually using these in my case).

Hope that helps.