This is an excerpt from an article featured in ATMOsphere’s “Clean Cooling for Data Centers 2025” report, which can be downloaded here. ATMOsphere is the publisher of NaturalRefrigerants.com. You can read part 1 of this story here.
Enrico Boscaro, Group Marketing Manager for HVAC Industrial at Carel, has a unique vantage point into where the data center cooling sector is headed. Along with his work at Carel he is also the chairman of Eurovent’s IT cooling task force. It focuses on technical issues in the area of data center cooling, such as the energy efficiency of cooling equipment, and communicates its opinions to regulators. Below are a few of Boscaro’s insights Eurovent’s work with regulators along with how Boscaro sees the industry evolving.
On the EU F-gas Regulation and possible PFAS ban
Enrico Boscaro: Both f-gas and PFAS are concerning, and the [Eurovent IT] working group is trying to have a dialogue with the EU to clarify limits and timing because many of those go in opposite directions, such as energy efficiency versus the usage of certain refrigerants. PFAS is concerning because of immersion liquid cooling, which uses large quantities of fluid in a tank, not gas in a sealed circuit. Any drop that falls might end up in the environment. In addition, there are new regulations about the carbon footprint and declarations on the lifecycle assessment of products. PFAS is related to refrigerants, but it’s also related to components. The thought is that a lot of these components might have to be changed.
On the Eurovent IT task force’s work on energy efficiency
EB: For example, EU regulators are looking for parameters to measure the efficiency of a CRAC unit, water- or air-condensed, and we gave them our minimum efficiency parameters. We’re still far from a seasonal efficiency approach and are struggling to communicate what is typical in this industry and how we should leverage free cooling when determining energy efficiency. The task force’s opinion is that we should focus on efficiency and not technology. They [regulators] have in their mind that propane [R290] is an exceptional refrigerant in terms of GWP, but here we’re talking about megawatts and having megawatts of propane on the roof of a skyscraper in Frankfurt. In an example like that, fire risk is a great concern.
On American companies building data centers in Europe
EB: This is something we [the Eurovent task force] told the European Union: that the big players from the U.S. are coming. They will probably [build data centers] with chillers using R32, which is not PFAS and has the right GWP. The quota mechanism is an issue, as is its flammability.
[Note: The 2024 revision of the EU F-gas Regulation establishes a maximum GWP of 750 for chillers above 12kW – except if required to meet safety requirements at the operation site – that comes into effect in 2027.]
On the future of air and liquid cooling in data centers
EB: Liquid cooling is growing at the fastest pace, and we’ve seen estimations of it taking 30% of the market by 2028. Liquid cooling is very well combined with AI and big data centers, but to support all of that you need the other data centers, which are growing at the same time. You need the internet to make AI run, and to run the internet you’ll still have some air cooling, which will probably be more free cooling.
On the importance of sensors in liquid cooling
EB: We are mostly involved with CDUs at the moment, and the big requirements are on sensors. There’s a lot of potential development there. Water quality is going to become very important. The heat exchanger that goes over a microprocessor is a microchannel heat exchanger with very tiny channels. CDUs have filters to remove small particles, as small as 20 micrometers, because one particle can clog a duct, and then one part of the microprocessor cannot be properly cooled.
On the biggest opportunity for natural refrigerants in data centers
EB: It’s probably CO2 [R744]. Mechanical cooling won’t be eliminated in the short term due to the amount of power and the fact that you need to go everywhere in the world. It’ll probably be free cooling most of the time, but then you will need a chiller, a very large one.
