Compiled by Eamonn Ryan based on the SAIRAC Johannesburg Centre Tech Talk on September 19 by Michael Young, mechanical engineer
As data centres have evolved, so have their cooling requirements, driven largely by the increasing demand for computing power. This is Part 3 of a ten-part series.
Michael Young, mechanical engineer.
© RACA Journal
In the early days, systems operated at a modest three kilowatts per rack, utilizing perimeter cooling units. As technology advanced and companies like Facebook and Google pushed the boundaries of application performance, the need for higher density cooling solutions became evident.
Initially, perimeter cooling sufficed, but as rack power consumption climbed, it became clear that a new approach was necessary. This led to the development of raised floor construction, which allowed for better air distribution across the data centre. However, as we reached around 15kW per rack and beyond, air began to lose its efficacy as a cooling medium. Its low heat capacity and high-volume requirements made it less viable, particularly in high-density environments.
To adapt, data centres have introduced several advanced cooling methods, including:
- Rear door heat exchangers (RDHX): This technology consists of a coil and a chiller. Water from the chiller is pumped to the back of the server rack, where it absorbs heat. The system maintains a single-phase water flow, allowing for effective heat exchange as cold air is blown out from the unit.
- Direct-to-chip liquid cooling: This is where the buzz around liquid cooling intensifies. Direct-to-chip cooling involves circulating liquid directly to the components generating heat, maximising cooling efficiency. This method is particularly effective for high-performance computing systems, including AI workloads.
Exploring liquid cooling solutions
As we delve deeper into liquid cooling, we can identify key components and design parameters essential for successful implementation. The integration of liquid cooling not only addresses heat management but also aligns well with the trends of increasing density and power consumption in data centres.
Why liquid cooling? Liquid cooling offers several advantages over traditional air cooling methods:
Higher efficiency: Liquid has a much higher heat capacity than air, allowing it to absorb and dissipate more heat with less energy
Space optimisation: As data centres scale up, liquid cooling can facilitate a denser arrangement of racks without compromising performance
Lower operating costs: With improved efficiency comes reduced energy consumption, translating to lower operational costs
Embracing the future of cooling
As we continue to explore these technologies, the role of AI in optimising cooling systems will become increasingly crucial. Liquid cooling, in particular, is set to play a vital role in the next generation of data centres, meeting the demands of advanced computing applications while enhancing sustainability.
The future of data centre cooling is not just about maintaining temperature; it’s about creating intelligent systems that can adapt and respond to the ever-growing needs of technology. As we progress, it’s essential to evaluate whether liquid cooling is the right fit for your data centre, considering both current requirements and future scalability.
