Nvidia’s solution to reduce water consumption in data centers to zero aims to be genius: use hot water

Nvidia has announced a system of liquid cooling very special. Above all, because the concept of “refrigeration” is a bit confused here. The company has managed to reinvent this type of systems, and according to those responsible “the challenge of water consumption for data centers it is practically solved.” That’s saying a lot… or isn’t it?

Jacuzzi cooling. The own Nvidia engineers They begin the description of their system by talking about how in jacuzzis the water is usually between 38 and 40 ºC, a temperature that makes most people last about 15 minutes in them. And the funny thing is that Nvidia’s new AI servers can use liquid cooling with water that is even hotter: up to 45ºC (113ºF). That is precisely the key to making the entire system efficient.

Goodbye to fans. Nvidia’s new Rubin architecture claims to be the first in the world with an end-to-end liquid cooling system. At Nvidia they seal the server boards and eliminate noisy fans that shoot noise levels above 85 decibels.

Elementary physics. The concept behind this idea is counterintuitive, but also brilliant. The chips generate so much heat that a liquid composed of 75% water and 25% propylene glycol entering at 45ºC is capable of absorbing the thermal load dissipated by these chips. The fluid absorbs that heat and ends up leaving the circuit at around 55ºC without the performance of the processor degrading at all.

Good for 45ºC. The key is that Nvidia starts from that starting temperature of the water, which is 45º. In a liquid cooling circuit in PCs, the liquid is usually between 25 and 30 ºC. Here Nvidia manages to ensure that with this initial temperature the thermal difference with the outside air is high enough for the system to work passively in most temperate climates. The heat is expelled by gigantic external radiators.

Water is only needed on the first fill. Even more interesting is the fact that this water circuit only needs to be filled once for the entire useful life of the plant, at least in theory. This eliminates traditional systems that use evaporative cooling towers. These systems consume enormous amounts of water, and according to Nvidia this makes it possible to cut water consumption of data centers by almost 100%.

But. Although Nvidia’s idea is promising, the company only talks about what happens within the four walls of data centers. The impact internally in the data center is extraordinary, but what about outside? The problem, they explain on TechCrunchis that data centers they need a lot of energyand both the generation of that energy and the creation of the chips themselves used in data centers can fold either triple to the consumption of the data center itself.

The gas and coal bill. Although renewable energies are increasingly covering a greater part of the needs in these data centersthe use of coal and natural gas will continue to be very notable in these facilities. According to the International Energy Association (IEA), these two sources will continue to represent 40% of the total used in AI data centers until at least 2030. And the generation of both types of energy requires vast quantities of water: natural gas plants they use 1.17 liters of water for every kWh of electricity they generate. Coal ones are even worse, requiring 2.2 liters per kWh.

Good news, but not so good. The system devised by Nvidia can solve the problem within data centers and is even promising when it comes to reduce noise levels generated by these facilities. However, there are still equally important challenges to ensure that water consumption in other phases of this cycle is not so colossal. It is a good step, without a doubt, but the room for improvement is still notable in this area.

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