Cooling fans are the next big Android phone trend you should avoid

While not an entirely new trend, the HONOR Win 2 series and OnePlus Ace 7 are just two in a growing list of Android phones launching with cooling fans onboard. What was previously just the purview of niche flagship gaming phones is quickly making its way to more affordable handsets with broader appeal.

In theory, this technology makes a lot of sense. PCs, laptops, and even handheld game consoles all have fans to help keep them cool while powering through intense workloads. So why shouldn’t high-performance smartphones benefit too, especially given that they’re constrained by small form factors that struggle to dissipate heat quickly?

Well, there are a few problems here, none of them particularly egregious on their own. But combined, they might put you off jumping on this growing Android trend to eke out every last bit of performance from the latest and greatest mobile processors.

How much difference can a small fan really make?

Let’s start with the really obvious: fans work really well in PCs and game consoles for two main reasons: there’s plenty of internal space to move air around, and the fans are large and can move a lot of air past the CPU’s equally large heatsink quickly.

Smartphones have neither of these properties, meaning a fan can cool only a usually modest surface area. For phones, a pressing issue is not just cooling the CPU but also preventing high temperatures near the user’s hand. A fan design might help keep heat localized, but it doesn’t guarantee that the internals or externals will cool faster than a well-designed passive system.

A fan can still outperform a passive system, but as surface area is a major contributor to heat transfer, a small fan alone is not the answer for vastly superior cooling. Effectiveness depends on the entire thermal design, including how efficiently heat is transferred from the processor to the surfaces exposed to that airflow. If the fan provides little airflow or the thermal pathway is inefficient, it won’t make a meaningful difference when the phone is under significant stress.

More to the point, small fans have to run faster, at a higher RPM, to move as much air as a bigger fan and effectively cool anything down. This means more motor whine and airflow noise, making the fan kicking in instantly noticeable. All the phones I’ve used that have a fan are rather noisy and distracting. This might not be a problem when you lock in with headphones on. But you’ll be quickly cast out of the living room and chastised on the morning commute for billowing hot air at the ears of anyone sitting nearby.

The effectiveness of these tiny fans is debatable as well. I’ve tested fan-equipped gaming phones in the past and found that turning the fan on or off makes little difference to the phone’s internal or external temperatures when maxing out its GPU. That isn’t to say it won’t help the phone maintain slightly better performance in worst-case scenarios — it could help avoid throttling towards the end of a very long gaming session, but I’m yet to observe a huge difference during 20 minutes of stress testing. The exception is ASUS’s much larger, external AeroActive Cooler system. In any case, temperatures are often more effectively controlled by a phone’s performance-profile software than by simply toggling a fan on or off.

When OnePlus claims its fan setup cools the inside of its upcoming Ace 7 smartphone by up to 10°C over a long session, that might be a genuine breakthrough. However, I’d still be cautious that the other trade-offs are worth any performance improvements.

An excuse to ramp up the power

Designing a cooling system to make something that’s already good even better is one thing, but it’s equally true that brands like to push performance to the limit and worry about cooling later. Everyone wants to be a benchmark topper, but as we’ve discovered, handsets targeting a significant performance edge almost always run far too hot to hold comfortably at full tilt. One concern is that manufacturers could use additional cooling headroom to further prioritize peak performance over efficiency, potentially leading to increased heat and/or reduced battery life.

Reports are already emerging that the latest Snapdragon 8 Elite Extreme Gen 6 chips can be run on the warmer side of ideal — 5GHz CPUs don’t come for free, after all. What’s to say that cooling fans aren’t just a way to actually keep some of these powerhouse phones running at remotely sane temperatures, while allowing them to scrimp on more expensive vapor chambers? Furthermore, could the growth in phones with fans encourage chip designers to push the thermal envelope beyond the realistic limits we’ve long since reached? I wouldn’t bet against it.

Of course, it’s not only top-of-the-line processors that we need to keep an eye on. These often benefit from being built on the latest manufacturing processes, which typically mean smaller, more efficient transistors and less power wasted as heat. At least in broad strokes, silicon vendors often leverage the latest nodes to pack in more transistors and/or ramp up clock speeds, which eats into any efficiency wins. Regardless, older flagship chips and modern mid-range processors can also generate substantial heat when manufacturers configure them to sustain demanding workloads at high performance levels. Higher performance can come at a disproportionate power cost, particularly when higher clock speeds require increased voltage. That extra power generates more heat and can reduce battery life, which means battery packs or being tethered to a USB-C cable.

Any phone, regardless of the price, that promises top-tier gaming performance but can’t be held comfortably in your hands or runs out of juice in a couple of hours is a compromise not worth making.

Space that could be put to better use

The final point is that even smartphone fans aren’t small, at least comparatively to the rest of the phone. Around a centimeter or so in diameter and several millimeters thick is, at the very least, the size of a quality camera module. Pair this with an ideally large cooling block on and around the processor, and we’re talking about several square centimeters of space and some significant depth required for a really robust fan-based cooling solution. Either that or additional bulk added to today’s increasingly lopsided, camera-heavy designs.

Now, mid-range phones might not be willing to splash the cash on a large camera sensor anyway, but it’s worth considering what that space could buy instead. An extra or improved camera, room for a wireless charging coil, or space for a bigger battery are all very useful, sought-after features that make a difference to everyday use. For serious gamers, giving up a larger camera or optimal 5G antenna placement might be a trade-off worth making. But if you’re looking for a well-rounded smartphone, it probably isn’t worth sacrificing a feature or two you can buy elsewhere for a similar price just for a built-in fan.

Gaming brands have also long sold cooling accessories that boast larger, admittedly bulkier fans, which seem like a better bet for keeping a handset cool when you really need it. If you really need to keep your phone running smoothly under heavy loads, there are often better solutions available than a tiny built-in fan.

Ultimately, phones are supposed to be pocketable devices that manage heat without noisy fans. If we’re pushing more power into them than they can comfortably handle, it might be time to consider a different form factor altogether. We’ll have to see whether this next generation of fan-equipped smartphones can live up to their promises. I remain skeptical, and I’m not convinced it’s a trend I would hop on, even if the temperature claims hold up.