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Small black square 40mm case fan with 4-pin PWM connector

Alphacool

Alphacool ES 40mm 400-10,000rpm case fan 40x40x20mm two ball bearing PWM 12V black 24823

SKU CH-A8Z4-9S76C

40 mm dual ball-bearing PWM fan runs from 400 to 10,000 rpm for server and workstation cooling

  • Fan size40 mm
  • Bearing design2 Ball
  • Power input connector4-pin PWM
  • Fan depth20 mm
  • Product typeCase Fan
  • 4-pin PWM enables wide speed control from 400 to 10000 rpm
  • Double ball bearing extends service life under full load
  • Soft start reduces mechanical stress and injury risk
  • 12 V operation with 0% PWM allows complete fan stop
  • Compact 40x40x20mm frame fits tight server and workstation chassis

40 mm PWM fan for servers and workstations

The Alphacool ES 40 mm fan measures 40x40x20 mm and spins from 400 to 10,000 rpm via a 4-pin PWM connector. It runs on 12 V and uses a double ball bearing for long service life under continuous load. The black frame suits rack and workstation builds that need reliable airflow in a compact slot.

Suited for server racks

Builders who need voltage-controlled 2-pin or 3-pin fans cannot use this model. The fan also stops completely at 0 % PWM duty cycle, so systems that require constant minimum rotation should choose a different design. It is not intended for standard desktop cases that only provide 3-pin headers.

4-pin PWM control and soft start change daily

Full voltage is always present on the 4-pin line while speed is managed by pulse-width modulation, enabling a wider control range and lower energy draw across the rack. Soft start reduces mechanical stress at spin-up and lowers the chance of injury during maintenance. The fan can be halted entirely when cooling demand drops to zero.

How it compares

Measured against everything we stock in PC Cooling Fans, at today’s prices. Recalculated every night.

Price $16.99
Cheaper than about 60% of the 8,339 comparable items (median $19.99).
Fan size 40 mm
Lower than about 90% of the 1,114 comparable items (median 120 mm).

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Specifications

Product
Product typeCase Fan
Power
Power input connector4-pin PWM
Size & build
Fan size40 mm
Bearing design2 Ball
Fan depth20 mm

Questions about this item

Does my motherboard need a 4-pin PWM header to run this Alphacool ES 40mm fan?

Yes, the fan uses a 4-pin PWM connector and requires a compatible header to receive full 12V power and PWM speed signals.

Will this 40mm 20mm-thick fan fit in the same mount as my older 40mm 10mm fan?

No, the 20mm thickness is double the standard 10mm depth, so it needs a mounting location with at least 20mm clearance.

How can I confirm the fan is operating correctly after installation?

In the BIOS or fan-control software, verify that the reported RPM changes smoothly between 400 and 10,000 as the PWM duty cycle varies, and that the fan stops at 0% duty cycle.

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