Case fans are a critical component of your PC’s cooling system. They help to keep cool air flowing over the CPU and GPU (graphics cards) which prevents throttling and overheating. In addition, they can be used to exhaust hot air out of your computer case, which helps to reduce overall case temperature.
Most cases come with a front intake fan and a rear exhaust fan, but it’s easy to add more. There are usually multiple mounting points in the front, back, top, and sometimes the sides of your case for different size fans. It is recommended to use fans with PWM support (Pulse Width Modulation) so that your motherboard can control the fan speed. This allows for better performance than older voltage-controlled fans as well as reduced noise level.
The goal when positioning case fans is to create an airflow channel from the right side/front of the case through the upper left/rear of the case, pulling cool air across the CPU and GPU and exhausting it out the back and/or top. This creates a cycle of cool air in, hot air out.
Also, remember that hot air rises, so your exhaust fans should be placed higher than your intake fans. This will help to ensure that the hottest components receive a constant flow of fresh cool air for cooling. If you do not have enough room for a rear exhaust fan, you can place another intake fan at the top of your case to help pull in additional cool air. Case fans