Opinion: What should I look for in a good cooling fan? - Overclock.net

pbasil1 · 02-06-06

Fans can help drop the temperature inside your case, and adversly lower your CPU,GPU,Chipset,and RAM temps, helping stabilitly for those units. Some people like me do not have money for watercooling or even better,phase change, so i have about 6 fans through out my computer case...Which placed correctly lowered my temps about 10-12c!

Choosing a case fan or better heatsink fan is not hard, but it does take a little bit of thought to it. When lookin for a fan, the most improtant aspect of it is the amount of air the fan can flow. This is referred to as "CFM" or Cubic Feet per Minuite. The more the marrier! For instance, an 80mm fan with a CFM rating of 30cfm will flow more air than an 80mm fan that is rated at 28CFM.

Airflow is not always affected by the size of the fan, but in most cases it is, thus u can find an 80mm fan that will flow more air than a 92mm or even a 120mm fan. This can be achieved by spinning the fins on the fan at a higher speed and also by changing the shape of the fins,but i wont get into the details of that;) Most fans have similar shaped fins so the faster the fan is turning, the more air flow it will produce (to an extent). But there is a down side to a high speed fan... Noise! Some people like to have a silent case, so when looking at fans we must also consider the "db" rating,or "Decible" rating,this is the unit for the measurement of how loud something is. The higher the louder

One way to lower db but still have a higher flow fan is to increase the size of the fan and lower speed of it, ex. a 80mm fan at 35cfm will have to spin at 3000rpm, producing ~38db... But a 120mm fan at 35 cfm will have to spin at 800rpm, producing ~16 db... The larger fan will produce the same airflow but be much quieter.I see many threads asking "how loud will this fan be?", "is it gonna wake my child up at night?" So below i have listed some generalized db ratings for you to compare...

10 db - Normal breathing
20-30 db - Normal whisper
40-50 db - normal talking, conversation
60-70 db - small group converstation, normal traffic
80-100 db - lawn mowers, power tools, big stereo system

Well this is about it when it comes to choosing a fan!. If I left something out let me know.
Thanks,
-=pbasil1=-