iQOO 15 Ultra's 17mm active cooling fan detailed in new schematic leak

The iQOO 15 Ultra is shaping up to be the most aggressive cooling solution ever put into a smartphone, and today's leak finally shows how that massive active fan will actually work. According to well-known leaker Digital Chat Station on Weibo, the device features a 17mm diameter fan that measures 4mm thick—reportedly the largest in the industry.

The schematic reveals a clever airflow design that addresses a fundamental challenge in smartphone thermal management. The air intake sits at the bottom of the camera island, drawing cool air from outside the device, while the exhaust port is positioned on the side frame. This creates a direct path for heat to escape the chassis rather than recirculating inside the phone.

How the cooling system actually works

The fan doesn't work alone. It's paired with what appears to be a substantial vapor chamber that spans much of the device's internal volume. In traditional smartphone cooling, vapor chambers spread heat across a larger surface area, allowing it to dissipate more efficiently through the phone's frame and back panel. The iQOO 15 Ultra adds active airflow to this passive system.

Here's the physics: when the Snapdragon 8 Elite Gen 5 SoC starts thermal throttling during intensive gaming, the vapor chamber absorbs the heat spikes and transfers them to the fan assembly. The fan then actively pushes that hot air out through the side frame, creating a continuous cooling loop. This should theoretically allow the chip to sustain higher clock speeds for longer periods without hitting thermal limits.

The 17mm fan diameter is significant—most active cooling phone accessories use fans around 10-12mm. A larger fan can move more air at lower RPMs, which means better cooling with less noise. The 4mm thickness suggests it's a centrifugal or "blower" style fan rather than an axial design, which is more efficient at moving air in tight spaces.

The broader context: gaming phones pushing boundaries

This isn't iQOO's first attempt at active cooling. The brand has experimented with external cooling accessories before, but integrating a fan directly into the chassis represents a different engineering challenge. You need to balance dust resistance, water resistance, structural integrity, and acoustic noise against thermal performance.

The rumored 7,800 mAh battery suggests this device is targeting marathon gaming sessions where sustained performance matters more than anything else. Combined with the same screen as the standard iQOO 15 and the top-tier Snapdragon chip, the Ultra variant is clearly positioning itself as a no-compromise gaming flagship.

What remains to be seen is how this affects daily use. Active cooling fans consume power, and the intake/exhaust ports could be vulnerable to pocket lint or moisture. The device will likely need robust IP ratings and smart fan control that only activates during heavy loads.

If the cooling system delivers on its promise, the iQOO 15 Ultra could set a new benchmark for sustained performance in mobile gaming. We'll know more when iQOO officially reveals the device, likely in the coming months.

Source: Digital Chat Station on Weibo (Chinese)