Comparing air-cooled vs liquid-cooled axial flux motors. While air cooling offers lower upfront costs, discover why liquid cooling saves more in weight, efficiency, and longevity.

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Liquid-cooled vs air-cooled axial flux motors: Which one will save you more?

When selecting an electric powertrain, the price tag on the motor is only the tip of the iceberg. The real cost—and the real savings—often comes down to how you manage the heat.

In the world of axial flux technology, there are two primary schools of thought: Air Cooling and Liquid Cooling. At first glance, the choice seems like a simple trade-off between cost and complexity. Air-cooled motors are generally cheaper and simpler to install. Liquid-cooled motors require pumps, radiators, and coolant.

But if you are building high-performance applications—whether for aviation, marine, or premium automotive—the "cheaper" option might actually cost you more in performance, weight, and reliability. Here is why Beyond Motors bets on liquid cooling, and why it is the smarter economic choice for serious engineering.

1. The Air-Cooled Trap: Low Cost, Low Ceiling

Air cooling relies on fans or natural airflow to dissipate heat from the motor’s surface. It is the dominant method for low-cost, low-power applications (like e-scooters or household appliances).

• The Pros: It is simple. There are no hoses to route, no coolant to leak, and the initial purchase price is often lower.
• The Cons: Air is a poor conductor of heat. To keep an air-cooled motor from overheating, you often have to "derate" it—running it at only 50% of its potential power.

To get high torque from an air-cooled motor, you usually have to make the motor larger and heavier just to increase the surface area for cooling. In industries like aviation or EV design, that extra weight is a "cost" you pay in reduced range and payload every single time you operate the vehicle.

2. The Liquid-Cooled Advantage

Liquid cooling circulates water or a glycol mixture directly through the motor housing or stator. This is the standard for the Beyond Motors AXM Series.

Because liquid conducts heat significantly better than air, we can push our motors much harder. This unlocks Continuous Power Density—the ability to run at high power indefinitely without overheating.

3. The "Hidden" Savings of Liquid Cooling

So, which one saves you more? If you look beyond the initial purchase price, liquid cooling offers three distinct financial and operational advantages:

A. Weight Savings = Energy Savings

Because liquid cooling is so efficient, a liquid-cooled motor can be 3x smaller and lighter than an air-cooled motor of the same power output.

• In an EV: A lighter motor means you can use a smaller battery pack to achieve the same range. Since batteries are the most expensive component of an EV, this saves significant money.
• In Aviation: Every kilogram saved on the motor is a kilogram gained in payload.

B. Sealed Reliability (Lower Maintenance)

Air-cooled motors often need "open" casings to let air flow over the coils. This invites dust, moisture, and salt spray (in marine environments) directly into the delicate internals.Liquid-cooled motors, like our AXM3, are fully sealed. They can operate in dirty, dusty, or damp environments without risk. This drastically reduces maintenance costs and prevents premature failure.

C. Magnet Longevity

Permanent magnets are expensive, and they degrade if they get too hot (a phenomenon called demagnetization). Liquid cooling maintains a stable, controlled temperature, protecting your investment and ensuring the motor lasts for years, not just months.

4. Why Beyond Motors Chooses Liquid

At Beyond Motors, we don't build motors for toys; we build them for machines that need to perform.

Our patent-pending cooling technology ensures that the AXM Series delivers the highest continuous torque in its class. We believe that for professional applications, reliability and power density are the ultimate savings.

Don't let heat limit your performance.Compare the specs yourself. Visit our Technical Configurator to model your powertrain, or contact our engineering team to discuss your cooling requirements.

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