Your iMac comes with a built-in fan that controls the internal temperature. It doesn’t come with a native feature allowing you to turn the fan up or down, so if you want to control the speed or frequency at which the fan operates, you’ll have to download a third-party application. The smcFanControl app will allow you to control the fan, though keep in mind that even those apps won’t let you set the fan’s speed below a level that is safe for the computer. Tips Writer Bio
