Summary of Key Points
With the surge in demand for AI computing power, server wattage has skyrocketed (for example, a 120-kilowatt cabinet is equivalent to 60 small heating units operating at full capacity throughout the day), making traditional air cooling methods utterly insufficient. The industry relies on three main approaches to address heat dissipation:
1. Liquid cooling technology (using cold plates or immersion methods) to remove heat from the chips;
2. Optimizing data center locations by placing them in cooler environments (such as the ocean, caves, or the Arctic Circle);
3. Reusing waste heat to generate heating or pool water.
Heat dissipation has evolved from a minor issue to a critical component of the AI industry, driving numerous innovative solutions.
Why Has AI Heat Dissipation Become a Matter of Life and Death?
In the past, servers had lower wattages (5-20 kilowatts), and a few fans were sufficient to dissipate the heat. However, AI cabinets now generate up to 120 kilowatts of power, which is like enclosing 60 small heating units in a 2-meter-high metal cabinet. According to the law of conservation of energy, almost all of this energy is converted into heat. The air is too thin to carry away such a large amount of heat, so even fast-running fans are ineffective, and the chips could overheat in minutes. This is similar to having 60 heaters in your living room—no air conditioner would be able to cool it down effectively; a more efficient cooling method is necessary.
How Do AI Servers Use Water for Cooling?
The mainstream approach is cold plate liquid cooling, where a copper cooling plate with fine water channels is placed on components like GPUs and CPUs. The heat is transferred to the copper plate and then carried away by the cooling liquid. This is currently the most common method.
For servers that need to be frequently plugged in and out for maintenance, engineers have developed quick-connect liquid cooling fittings with spring-loaded valves that automatically open to allow water flow and close to prevent leaks, ensuring safety similar to that of power cables. Huawei has taken this concept a step further by integrating power, networking, and cooling systems into a single bus, allowing servers to be connected and powered up without the need for manual tubing inspections.
What about the heat from the memory and hard drives? ZTE has developed water cooling curtains, replacing the rear door of the cabinet with a water-cooled plate to cool the hot air before it is released. A CDU (Centralized Data Unit), similar to a dedicated heating system, separates the server’s precision water circuits from the external pipes, preventing clogging. Google’s CDUs can circulate up to 1,900 liters of cooling liquid per minute.
Lenovo claims that their liquid cooling system can transfer 98% of the heat through the pipes, eliminating the need for a separate data center air conditioner in 100-kilowatt cabinets.
More Extreme Cooling Methods: Immersion Liquid Cooling
Another approach is to immerse the entire server in a non-conductive fluorinated compound liquid with a boiling point lower than water. When the chips generate heat, the liquid boils and produces steam that is then condensed and recycled. For example, Shuguang Digital創新的C8000 system, released in 2026, was designed to support megawatt-level cabinets (1,000 kilowatts), making it more efficient than cold plate cooling. NVIDIA’s Vera Rubin cabinets also incorporate this technology, integrating computing, networking, and cooling systems.
Moving Data Centers to Cooler Locations
To reduce energy costs, engineers are utilizing natural cooling sources:
- Shanghai Ocean: Data centers are placed 10 meters underwater, where the sea water remains at around 10 degrees Celsius year-round, significantly reducing cooling costs.
- Guizhou Caves: Tencent’s Guian Data Center is located in a cave with an average annual temperature of 14-16 degrees Celsius, cutting cooling costs by 40 million yuan annually.
- Arctic Circle: Microsoft has built a data center in Narvik, Norway, where the cold climate and affordable electricity make it ideal for cooling. The center has a capacity of 230 megawatts.
Recycling Waste Heat
The heat generated during cooling can be repurposed:
- Finland: Microsoft’s data center uses a heat pump to raise the temperature of water from 25-40 degrees Celsius to meet heating needs, connecting it to the Helsinki heating network. The investment in the heat pump (225 million euros) is expected to save long-term energy costs.
- Paris Olympics: The hot water for the 2024 aquatic sports center was provided by the waste heat from the Paris PA10 data center, also heating more than 1,000 residential units in the area.
In summary, as AI becomes more popular, heat dissipation becomes increasingly important. Each aspect of the process—chips, data centers, and waste heat utilization—opens up new business opportunities and helps make AI more environmentally friendly by reducing its carbon footprint.