The lifespan of a DC computer case fan is influenced by several factors. One of the primary factors is the quality of the fan's bearings. There are different types of bearings used in fans, such as sleeve bearings, ball bearings, and fluid dynamic bearings. Sleeve bearings are relatively inexpensive but have a shorter lifespan, usually around 10,000 - 20,000 hours. They are more prone to wear and tear over time, especially if the fan is operated continuously at high speeds.

Ball bearings, on the other hand, are more durable and can last up to 50,000 - 100,000 hours. They offer better resistance to friction and can handle higher loads. Fluid dynamic bearings combine the advantages of sleeve and ball bearings. They provide smooth operation, low noise, and a long lifespan, often exceeding 100,000 hours.

The operating environment also plays a significant role in the fan's lifespan. If the computer is placed in a dusty or dirty environment, the dust can accumulate on the fan blades and inside the bearings. This can increase friction and cause the fan to wear out faster. High - temperature environments can also accelerate the degradation of the fan's components, especially the lubricants in the bearings. Regularly cleaning the computer case and ensuring proper ventilation to maintain a cool operating temperature can help extend the fan's lifespan.