For continuous-operation equipment such as UPS and telecom systems, plan replacement based on rated life - typically 30,000-70,000 hours at 40°C - rather than waiting for failure.
How can I reduce cooling fan noise?
Run a larger fan at lower speed, check mounting for resonance, use damping pads and keep air paths clean. Fan speed is the dominant factor in noise.
Which bearing type should I choose?
Ball bearings offer longer life and better high-temperature performance, while sleeve bearings are cost-effective for lighter duty. Match the bearing to operating temperature and expected life.