Tech Stories

Issue #70

Hello Reader,

Today, let's talk about life-giving water. What role does water play in the functioning of modern data centres, and what could possibly go wrong? For the former: Everything. And a lot could go wrong, it turns out.

Before we go into that, a bit about what happened this week.

Data Centre World Asia

Some of you reached out ahead of DCW and invited me to your booths, which I duly noted on my to-do list. But I didn't actually get the chance to spend much time in the exhibition area. I did make sure to send a personal note to everyone I couldn't meet - and if I somehow missed you, my apologies.

So what happened? I was at MBS for almost 12 hours on Wednesday, and most of that time was spent having conversations outside the hall. I've been writing about data centres for a decade now, yet the more I learn, the more I realise how much I still don't know. It's both humbling and exhilarating.

There's something revealing about hearing claims from a particular brand, then asking an expert hours later only to learn of some glaring downside that was conveniently downplayed. Truly, knowing what to ask is half the answer.

I'm thankful for those who freely shared their insights with me over coffee or canapés. As always, I'll do my best to share what I've learned in the days and weeks ahead.

When water isn't just water

Back to the topic of water. One of the first revelations from these conversations was that one would imagine water to be, well, water. Turns out there's far more nuance to this essential resource than meets the eye, as I learned on Wednesday. Water source quality bears particular mention, as it's influenced by factors such as contamination, pollution, and dissolved minerals in groundwater.

Why does it matter? The quality of water heavily influences the Cycles of Concentration (CoC), which determines how many times water can be recirculated in a data centre before being discharged. The CoC can vary from low single-digits (bad) to double digits (good). In case you were wondering how water is used in data centres, I explained it earlier this week.

Here's what made me sit up this week. As data centres increasingly process their own water in the face of evolving regulations that prohibit using only municipal water, not everyone is adhering to the same quality standards. Right now, the verdict is still out whether equipment lifespan will be substantially impacted - we just don't know.

But if data centres are becoming their own water utilities, should they be required to meet certain water quality standards? While that question hangs over the industry at a facility level, the challenges with water get even more complex and immediate as we move inside the rack.

Liquid cooling's hidden threats

What could possibly go wrong with liquid cooling? A lot, it turns out. And I'm not just referring to leaks that damage top-of-the-line GPUs costing millions of dollars.

Speaking at the Ecolab Liquid Cooling Seminar on Friday, Nalco Water's Dr Lu Kangjia (Kelly) showed us rather disturbing images of what could go wrong on the TCS loop between the CDU and IT racks. The hidden threats? Scale, biofilm, fouling, and corrosion - any of which could trigger outages or unscheduled downtime. In data centres, that's about as welcome as a power cut.

Her recommendations cut straight to prevention: proper selection of coolant, metallurgy, and non-metallic components for the TCS loop. Coolant quality needs careful management through filters, sampling, and monitoring. And here's what many miss - you need to communicate with vendors to ensure the non-metallic components in your TCS loop won't leach unwanted chemicals into your carefully maintained water chemistry.

Nvidia's Dr Ali Heydari, who invented liquid cooling for the AI giant, also laid out various technologies he is current piloting in his keynote. One standout: digital control valves for discrete liquid flow control. Why does this matter? Tomorrow's data centres will likely be a homogeneous environment with 1MW racks coexisting with 130kW racks, and this won't be possible with today's cooling systems.

As I said during the panel discussion: "If you think that the evolution of the data centre is going to stop with your one-megawatt rack, well, there are other innovations coming up. And the data centres of five- or 10-years' time could be very, very different from what we see today. Fasten your seat belts."

As always, you can reach me by hitting reply.

Regards,
Paul Mah.

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