24V DC Axial Fan for Electronics Cooling: 60mm Case Study

What the enquiry actually asked for

Everything in this project started from a 60 by 60 by 25 millimetre hole. The customer, a system integrator, had already fixed the enclosure, so the 24V DC axial fan had to work inside that envelope or not at all.

The power architecture was equally settled. Nominal supply was 24 VDC, but the bus could sag to 12.0 V or climb to 26.5 V depending on load, so the fan needed to keep turning across that whole range. The reliability engineer also insisted on dual ball bearings rather than a sleeve type. That request tells you something useful about the application: it sits somewhere awkward to service, and nobody wants to open the box again in three years.

• Roughly 15 CFM of airflow, measured at the operating point rather than free air.
• At least 4.0 mmH2O of static pressure, around 39 Pa, to push through a dense fin stack.
• Ambient temperatures from -10C to +60C.
• Dual ball bearings for extended life.
• UL and CE marking for North American and European sales.
• UL94V-0 rated plastics, in line with IEC 62368-1 for information technology equipment.

Here the pressure figure is the part that decided this project. Plenty of 60mm fans move 15 CFM in open air. Far fewer still do it once a heatsink and a crowded board are in the way, which is why the 24V DC axial fan selection took longer than the frame size suggests.

Picking the right 24V DC axial fan

With the frame size and the voltage both fixed, the only real decision was which variant of the LWAD6025 series to put in the enclosure. The series spans several speed and power grades. Naturally, the temptation is always to pick the quiet one.

Why the quieter model was rejected

We looked at the quieter LWAD6025LH-13 first. Its peak static pressure is 4.72 mmH2O, or about 46 Pa. On paper, that clears the customer’s 39 Pa requirement. In practice it does not. A fan operating within a few pascals of its shut-off point delivers almost no air. Reading its P-Q curve at the real duty point showed the airflow falling well short of 15 CFM. There was no margin left for a dirty filter or a warmer day either.

The variant that cleared the duty point

So the specification went to the top of the series. The LWAD6025MX-14 is the fastest 24V DC axial fan in the family. A more powerful brushless motor takes it to 6000 RPM nominal, and its curve delivers comfortably more than 15 CFM at 4.0 mmH2O. Above all, that headroom is what keeps the selection defensible over the life of the product.

The trade-off is honest and worth stating. This 24V DC axial fan draws 7.6 W and runs at 41.5 dBA, against much lower figures for the slower models. For a quiet office device that would be unacceptable. Here, though, the semiconductors were the constraint, not the acoustics, so the noise was the right thing to spend.

Bearings, materials and protection

Dual ball bearings went in as requested, giving an L10 life of 50,000 hours at 25C. Frame and impeller are PBT, which satisfies UL94V-0 without a separate flame-retardant treatment. In addition, the same material holds its shape at the top of the temperature range. The motor electronics include locked rotor protection, so a blocked impeller will not cook the windings during the 72 hours nobody is watching. The final approved part number, LWAD6025MX-14-00, went straight onto the customer’s bill of materials.

Technical Specifications

Meanwhile the combination of 47.78 m³/h free-air delivery and a high shutoff pressure of 82.4 Pa makes this 60mm fan suitable for densely packed electronics with moderate system impedance.

Technical Documentation

The definitive engineering datasheet, LWAD6025MX-14-00, contains all performance curves, mechanical drawings, and electrical specifications for OEM integration.

Here the product image and series comparison table helps engineers visualize the fan and select the correct performance variant from the LWAD6025 family.

The project’s source documentation file, LWAD6025MX-14 Project File, provides supplementary data for procurement and quality assurance teams.

Why the OEM bought from us

This was a catalog part, not a custom development. Even so, the supplier choice still mattered once the 24V DC axial fan moved into volume production.

• Cost at the specification, not below it. The dual ball bearings, the UL-rated plastics and the protected brushless motor are all in the build. None of them were traded away to reach a number, which is the trade most often made on a fan in this class.
• Performance data you can design against. Our curves are measured in house and verified independently to AMCA 210/211 and ISO 5801 methods. That saves the customer from running its own incoming performance checks.
• Supply that does not wobble. Longwell has manufactured in Ningbo since 1990. Furthermore, we ship over 120,000 data center fans a year, so a 60mm axial fan sits well inside that comfort zone.
• Batch-to-batch consistency. Our ISO 9001 system controls winding, balancing and dimensional tolerance. An OEM building thousands of identical units needs identical acoustics from each one, and that only comes from process control.

Browse the full DC axial fan range, or compare it with our EC axial fans where speed control is required. Test methods are published by AMCA International.

Questions that came up during selection

Why not use a sleeve bearing fan to save cost?

Sleeve bearings are cheaper and quieter when new. However, their life falls sharply at raised temperature, and this 24V DC axial fan sees ambients up to 60C. At that point a ball bearing version lasts several times longer. That matters far more than the small price difference when the equipment is hard to reach.

Can this fan run below its 24V rating?

Yes. The operating window runs from 12.0 to 26.5 VDC, so the fan keeps turning through a sagging bus. Speed and airflow drop with the voltage, though. For that reason, size the selection at the lowest voltage you expect rather than at nominal.

What does 41.5 dBA sound like in practice?

It is audible in a quiet room, but unremarkable in a rack or an equipment cabinet. If the application is noise-sensitive, meanwhile, a larger frame turning more slowly usually beats a quieter 60mm fan.

Do you supply the P-Q curve before we commit?

Yes. We send the measured curve, the dimensional drawing and the UL and CE documentation with the quotation, so your thermal engineer can check the duty point before any order is placed.