Icebox Energy

Transforming Data Center cooling

[Chamath Palihapitiya @chamath]

Whenever I have an opportunity to partner with a brilliant technologist to build something special, I do so.

A few years ago, Matt Stroud (my brilliant cofounder) set out to rebuild the heat pump. Here is a summary of our company: @Icebox_Energy

Problem Statement:
We are building an end-to-end cooling solution for data centers using CO2.

Why:
Next-generation HPC/AI processors produce heat beyond the capabilities of traditional cooling. Only four viable options exist: two-phase immersion cooling (impractical and environmentally hazardous), impinged water jets (complex and leak-risky), two-phase refrigerant cold plates (environmentally concerning), and Icebox Energy’s CO₂-based solution. Our single-loop CO₂ system simplifies design, reduces risks, and significantly lowers costs while providing higher reliability, easier maintenance, and better scalability.

Emerging HPC/AI processors produce more heat than can be managed by state-of-the-art air or liquid cooling systems. Future data center builds will require advanced cooling solutions to handle both the extreme heat density of these next-generation processors and rapidly increasing rack power levels—currently around 140 kW and soon reaching 1 MW. Compounding this challenge is limited grid power availability, making it essential that advanced cooling solutions become more efficient—freeing up additional power for computing workloads.

There are only four practical cooling options capable of handling these demands: two-phase immersion cooling and three direct-to-chip (cold plate) solutions—impinged water jets, two-phase refrigerant cold plates, and Icebox Energy’s CO₂-based technology.

Two-phase immersion cooling is unlikely to scale effectively. Although it delivers impressive energy performance, immersion requires submerging entire servers into sealed vats filled with fluorinated chemicals, making it impractical and posing significant environmental and health risks. This leaves the three cold plate options.

Impinged water jet cold plates utilize water, but managing water chemistry and high flow rates for these applications is challenging, and leaks pose serious risks to IT equipment.

Two-phase refrigerant cold plates rely on the same fluorinated chemicals (HFOs) used in immersion cooling, though in much smaller quantities. While the environmental impact is reduced, concerns around safety, cost, and long-term regulatory restrictions remain.

Both impinged water jet and two-phase refrigerant cold plates require multiple cooling loops, introducing additional points of potential failure and increasing heat losses.

Icebox Energy's system transfers heat from the server directly to its heat pump in a single loop. Operating at pressures similar to those in restaurant soda fountains and grocery store refrigeration systems, the direct and pressurized CO₂ approach eliminates numerous components, such as pumps and heat exchangers, significantly reducing the size and complexity of the cooling system. CO₂ can carry 10x the heat compared to water in half the size and is 30x denser than HFOs, allowing smaller return lines. As a result, the system is more compact, uses significantly less coolant, and costs substantially less than systems using HFOs. Our CO₂ system also provides numerous additional advantages, including enhanced reliability, simplified maintenance, and greater scalability.

We can support all proposed coolant temps in all climates.  Our tech offers the lowest PUE at the best price and highest reliability (5-9s+).

Please follow us @Icebox_Energy if you're interested in keeping up to speed with what we are up to.

[Icebox Energy @Icebox_Energy]

We’re proud to share that Icebox Energy was selected by the iMasons Innovation Incubator, a global program supporting early-stage technologies poised to reshape digital infrastructure.

The incubator connects emerging solutions to a curated network of leaders across hyperscalers, utilities, colocation providers, and engineering firms.

Press release: https://t.co/vmS4CpvyoD

[Icebox Energy @Icebox_Energy]

Let’s talk energy efficiency. Our revolutionary data center cooling system achieves 10x the cooling density of water in half the size, with cooling capacities reaching +500kW/cabinet and PUE ranging from 1.2-1.03. #EnergyEfficiency #DataCenters

[Icebox Energy @Icebox_Energy]

What makes @Icebox_Energy different from other data center cooling companies? We are the ONLY one that uses zero water and zero forever chemicals. And we’re energy efficient too! #EnergyEfficiency #sustainable #WaterEfficiency #DataCenter #noforeverchemicals #sustainablefuture

[Icebox Energy @Icebox_Energy]

AI is here to stay. We can pump many thousands of gallons of water a day to cool data centers—draining this precious resource, depleting groundwater reserves where it’s needed most.

Or, we can cool data centers without using A. Single. Drop.
That’s what we do @Icebox_Energy

#DataCenterCooling #datacenters #WaterEfficiency #sustainable #waterconservation

[Bloomberg @business]

A Bloomberg News analysis finds that roughly two thirds of new data centers built or in development in the US since 2022 are in places with high levels of water stress. https://t.co/bdwUXqrWhy

[Icebox Energy @Icebox_Energy]

@Microsoft developed a cool new tool that quantifies water and energy usage over the life cycle of a data center. But what if the path to data center water efficiency is to not use any water at all? #DataCenterCooling #DataCenters #WaterEfficiency

https://t.co/8An4IjEMJt.

[Icebox Energy @Icebox_Energy]

@MarcDrellishak @chamath Stay tuned!

[Icebox Energy @Icebox_Energy]

@GregoryWilken @chamath @SpaceX Or small and efficient enough not to matter?

[Icebox Energy @Icebox_Energy]

@mattleydig @chamath Nope, not our system. We're helping AI get more efficient not less.

[Icebox Energy @Icebox_Energy]

@JacobLBrown @chamath Good questions! Current gen chips produce 100x compute for 3x power, so we're getting there but they're still hot! and getting denser.

[Icebox Energy @Icebox_Energy]

@x_a_n_d_e_r_g @chamath Great question. Our systems can fluctuate between subcritical and transcritical operation and is built to cool next gen chips and racks, think 250 W/cm^2 gpus and 1MW racks (if you can call them racks at that point)

[Icebox Energy @Icebox_Energy]

@Glennedgar3 @chamath Not ours. CO2 is already commonly used in grocery stores as a refrigerant. Fire suppression systems have moved on to other chemistries all together and although there is less risk to oxygen consumption they are nasty chemicals to deal with.

[Icebox Energy @Icebox_Energy]

@rwintle @chamath Similar to a soda fountain.

[Icebox Energy @Icebox_Energy]

@Glennedgar3 @chamath No. And CO2 doesn't harm IT.

[Icebox Energy @Icebox_Energy]

@mehkhi07 @chamath Would love to see it. Feel free to reach out to our team.

[Chamath Palihapitiya @chamath]

As per the usual with physics/thermo things, Elon is right.

We started Icebox a few years ago to help bring new industrial solutions to heating/cooling anticipating constraints in next-gen systems.

In a nutshell, we invented a first of its kind high-density cooling platform designed for the demands of advanced computing: using first principles to replace chillers, facility water, and cooling towers with a carbon dioxide loop. This achieves a 10x cooling density compared to water in half the size, a step function improvement in HVAC.

Next gen AI will not work without supercharged cooling— best in class/SOA isn’t keeping up with with the power emissions of chips.

Our solution can also elegantly translate to HVAC for home.

We're just getting started but you can follow along here @Icebox_energy

[Icebox Energy @Icebox_Energy]

We are Icebox Energy, and we are transforming data center cooling. More to come!

https://t.co/l4MXba8hLT