RTX 4090 liquid cooled using an Air conditioner delivers amazing results

Nvidia’s RTX 4090 runs at 20 degrees under load with air-con cooling – Next up is an RTX 5090

A Chinese techtuber on Bilibili (via Tom’s Hardware) has a liquid-cooled PC using a 12,000 BTU air conditioning unit. This custom setup is intended for a future RTX 5090-powered PC, though the user is currently awaiting a compatible water block to enable this testing. This PC may feature the world’s first air conditioner-cooled RTX 4090 graphics card.

Using this insane setup, Nvidia’s RTX 4090 GPU can run stress tests with 20 degrees Celcius load temperatures. This custom liquid cooling setup also cools an Intel i9-13900K CPU. In time, this system will be upgraded with an Intel i9-14900K CPU and an Nvidia GeForce RTX 5090 GPU.

While the PC itself may look pretty normal, its attached cooling solution is anything but. Using custom connections, this PC is hooked into a customised Xiaomi KFR-35GW air conditioner. This air conditioner has been given Nvidia, AMD, and Intel branding, suggesting that it may be used to cool AMD-powered PCs in the future.

Power-wise, this air conditioner uses around 1.2 kW of power to generate 12,000 BTU of cooling. That’s a higher power draw than most gaming PCs. It’s also much larger with its 765 x 268 x 550 mm size.

After a full suite of testing using Furmark and AIDA’s System Stability Test, this system’s i9-13900K CPU was found to only be running 2 degrees hotter than when the test started. That was after 40 minutes of testing.

Moving the air conditioner outside, this system’s RTX 4090 GPU ran at 2 degrees Celsius at idle. Under load, the GPU’s temperature rose to 20 degrees, with a 36-degree hotspot. RTX 5090 load temperatures are not expected to be much higher.

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