Precision Liquid Cooling: Iceotope's Case for the Whole Board

Leading up to the AI Infra Summit in September, we're continuing our conversations with AI infrastructure companies across the stack, from hyperscalers to storage, memory and network, to power and cooling and beyond.

I had the pleasure of sitting down with Simon Jesenko, chief executive officer/ chief technology officer of Iceotope, a precision liquid cooling player. Here's what I learned:

Q1: Iceotope’s precision liquid cooling seals the server and pulls heat off every component, not just the processor, with a dielectric coolant. What does cooling the whole board let an operator do that a cold plate on the chip alone can’t?

A: Cooling a server with direct-to-chip cooling may still require air cooling for the components that are not cooled by the cold plates. Cooling the whole server with dielectric fluid allows the operator to cool all heat generating components within the server: GPUs, CPUs, memory, networking, and PSUs.

Sealing the server into a protective enclosure and eliminating air cooling removes fan noise and allows the server to be positioned anywhere within the rack and the room. Cooling with dielectric fluid removes any fear that the operator may have about the proximity of water / PG25 inside the server. Servicing does not require the connection, disconnection, or modification of any plumbing containing water / PG25.

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Q2: Precision liquid cooling isn’t only for the hottest GPUs. You cool storage, networking, and mainstream servers too. What kind of workloads and environments does that open precision liquid cooling up to?

A: This allows high-performance computing to move out of an air-cooled server room or data center, and to where it is actually needed. Customers can bring their compute clusters on-premises and deploy in harsh environments in a ruggedized chassis. Since Iceotope seals the server in a protective enclosure without fans, hardware is not exposed to external contaminants, so it can be deployed in harsh environments. Dielectric cooling fluid operates at temperatures up to 35° C, so it can effectively cool systems in extreme / outdoor environments

Q3: As rack densities pass what air and single-method approaches can carry, how far does chassis-level liquid cooling scale, and what changes along the way?

A: Hotter components, or more concentrated hot spots in the server can be cooled with fluid, depending on its temperature and flow rate. Hotter components require colder coolant and higher flowrates. The effectiveness of the coolant at (re)moving the heat is dependent on its specific heat capacity. Water has a higher heat capacity than dielectric fluid but it cannot come into direct contact with electronic components.

At scale, the factor against which all liquid cooling will be measured is the temperature of the coolant into the rack’s manifold (whether this is water/PG25 or dielectric. Currently, the target for this temperature is 45ºC. Any step (heat exchange) between two fluids or fluid to air is an inefficiency in the system (as some heat is lost in the process). As a result, the most efficient system is one which has fewer (or no) heat exchangers.

Q4: Your system captures almost all of the heat into liquid, so it can be reused rather than dumped. What does capturing heat that cleanly open up for an operator?

A: Captured heat can be reused in other deployments, for example a precision liquid cooled data center in a hotel basement could use the excess heat to heat the hotel pool. The heat capture and reuse ability turns datacenters into a community asset rather than a drain on resources.

Q5: What is the biggest thing still standing between precision liquid cooling and mainstream adoption, and how are you closing that gap?