Fan Noctua 40x40x20mm 5V 5000rpm - NF-A4x20-5V

This is the 40 mm fan Noctua NF-A4x20-5V – a compact 5V solution for cases and small systems where space is critical, but you don't want to sacrifice silence. With a thickness of 20 mm and a standard size of 40 x 40 mm, you can install it in mini ITX cases, small NAS devices, routers, media boxes, or other custom projects. It operates at 5000 RPM, but with a noise level of only 14.9 dBA, which is unusually quiet for such a small fan. Add to that SSO2 bearing plus 150000 hours MTBF and you get a small but very durable cooler.

What you get: a fan that operates at 5 V, making it ideal for devices and projects that do not use standard 12 V PC fans – mini computers, SBC (like Raspberry type systems), networking equipment, and more. With a thickness of 20 mm, it provides better airflow than classic 40x10 mm fans – up to 5.53 CFM / 9.4 m3/h, which helps lower temperatures without raising unnecessary noise. The consumption is minimal – only 0.5 W at 0.1 A, so it will hardly load your device's power supply. The standard 3-pin connector makes it easy to connect to a motherboard or controller that supports 5 V fans. Combined with long life and low noise, you get something you install and forget it exists.

• Compact fan with a size of 40 x 40 x 20 mm, suitable for tight spaces in small cases, NAS, routers, and custom projects.
• High speeds of 5000 RPM, providing stable airflow even in limited size.
• Airflow up to 5.53 CFM / 9.4 m3/h, sufficient for effective cooling of small radiators, chips, and enclosed volumes.
• Extremely low noise level of only 14.9 dBA, so your system remains almost silent even under continuous operation.
• Reliable SSO2 Bearing and MTBF 150000 hours, meaning years of continuous operation without frequent replacement.
• Operation at 5 V with consumption of only 0.5 W and current 0.1 A, suitable for sensitive or low-power devices.
• Standard 3-pin connector, which facilitates connection to motherboards and controllers that support 5 V fans.

This fan is particularly suitable if you are building a compact build, cooling networking equipment, NAS, or a small server and need a 5 V fan that is both quiet and reliable. It is not optimal for classic PC cases where the standard is 12 V and larger sizes (80/120/140 mm), but for niche and DIY scenarios, it is right on target.

The combination of 5 V operation, low noise, long life, and quality bearing in this small 40 mm format makes the NF-A4x20-5V one of the more sensible solutions if you want to solve a cooling problem "once and for all" in a compact device.