be quiet! Fan 140mm - SILENT WINGS 4 140mm PWM

be quiet! SILENT WINGS 4 140mm PWM is a 140 mm fan, aimed at quiet and stable operation in quality gaming and workstation cases or on coolers. It combines a very low noise level of 13.6 dBA with decent airflow of 51.3 CFM, making it a good choice if you want a balance between cooling and acoustics. It operates at 12 V, with consumption up to 3.6 W and a maximum of 1100 RPM, controlled via a 4-pin PWM connector. The classic all-black design fits easily into any build without visually dominating.

What you get

With this fan, the focus is on smooth and silent operation – the 6-pole motor and dynamic fluid bearing reduce vibrations and ensure smoother rotation compared to standard solutions. With 51.3 CFM / 87.16 m³/h airflow and 0.92 mmH2O static pressure, the fan is well-prepared for operation through dense mesh panels, filters, or radiators and heat sinks. The specially optimized blades and the frame with funnel-shaped outlets help direct air more effectively, rather than letting it scatter. PWM control allows you to drop to 0 RPM at low temperatures for a completely silent idle mode. With a declared MTBF of up to 300 000 hours, you can install it and forget about it for a very long period.

• Size 140 x 140 x 25 mm – standard 140 mm format for front, top, rear mounting, or on suitable radiators and heat sinks.
• Speed up to 1100 RPM (with possible 0 RPM) – low maximum speed for quiet operation and an option for a fully passive mode under light load.
• Airflow 51.3 CFM / 87.16 m³/h – sufficient flow rate for a stable air tunnel in the case or to assist CPU/GPU cooling.
• Static pressure 0.92 mmH2O – better efficiency through radiators, filters, and dense fins of radiators and heat sinks.
• Noise level 13.6 dBA – practically inaudible at normal speeds, suitable for a quiet room or workspace.
• 6-pole motor + dynamic fluid bearing – less vibration, smoother rotation, and longer fan life.
• Anti-vibration mounting and push pins/screws option – easier installation and less vibration transfer to the case.
• MTBF up to 300 000 hours – super long life, suitable for 24/7 machines as well.

Who it is suitable for

It is suitable for quiet gaming configurations, workstations, and home PCs where acoustics are a priority, but you do not want to completely sacrifice airflow. A good choice for CPU coolers or radiators that operate at lower speeds but need good static pressure. If you are chasing maximum airflow at all costs and do not care about noise, a more aggressive fan with higher RPM might appeal to you more.

The combination of quiet operation, PWM control, long life, and optimized blade design makes this be quiet! fan a very meaningful upgrade for a build where you want cooling without excessive noise.