Wearing your fan out is a BAD idea, and you can usually notice that if a fan gets noisy or squeaky, it needs to be replaced. Some motherboards will control the rate of fan spin based on the heat of the processor. Case Fans Your power supply comes with a big fan that blows the hot air out of the power supply. Sometimes, this is all you need to circulate air in your case. However, if you want to be more careful and keep your processor and other components from overheating on hot days, you will put an extra one or two fans in your case.
Most decent cases have a few spots to install fans.
Case fans are not required, but recommended. If you choose to put some into a case, put one sucking air into the bottom front of the case, and blowing the hot air out in the top rear of the case. As we all know, hot air rises. Dust is your enemy Items that touch more air get coated with more dust. Heatsinks do not dissipate heat as well when dust builds up.