DC computer case fans are essential components for maintaining optimal internal temperatures in a computer system. The motor types used in these fans play a crucial role in determining their performance. One of the most common motor types is the brushed DC motor. This type of motor consists of a rotor, a stator, and a commutator with brushes. The brushes make contact with the commutator to transfer electrical current to the rotor, which then generates a magnetic field that interacts with the stator's magnetic field, causing the rotor to rotate. Brushed DC motors are relatively simple in design and cost - effective. They can provide a high starting torque, which allows the fan to quickly reach its operating speed. However, the brushes in brushed DC motors are subject to wear and tear over time. As the brushes wear down, they can cause increased electrical resistance, leading to reduced motor efficiency and eventually motor failure. This limits the lifespan of fans equipped with brushed DC motors.

Another popular motor type is the brushless DC motor. In a brushless DC motor, the commutation is achieved electronically through a controller. This eliminates the need for physical brushes, resulting in several advantages. Brushless DC motors have a much longer lifespan compared to brushed DC motors because there is no mechanical contact between the moving parts for commutation. They are also more energy - efficient, as there is less energy loss due to friction and electrical resistance. Brushless DC motors can offer more precise speed control, which is beneficial for maintaining the right balance between cooling performance and noise levels. They can adjust their speed according to the temperature of the computer components, running at a lower speed when the system is not under heavy load to reduce noise and consuming less power, and ramping up the speed when the components get hotter to provide sufficient cooling.