The way we cool data centers is about to change, again.

This time, it’s not a story of power usage effectiveness (PUE) or mechanical innovation. It’s not a question of whether to deploy liquid or air cooling, or where to place your CRAC units. It’s about the coolant at the system’s core. A global regulatory shift is forcing the cooling industry to rethink its dependence on high-GWP (global warming potential) refrigerants. While these substances have powered decades of efficiency and reliability in traditional HVAC systems, they now sit in the crosshairs of environmental policy, and compliance timelines are shorter than most in the data center world are used to.

For operators, engineers, and construction teams, the message is clear: the refrigerant revolution is underway, and planning for it must start now.

Why Refrigerants Are Under Pressure

The climate impact of refrigerants has been well-known for years. HFCs (hydrofluorocarbons) like R-134a and R-410A, mainstays in many data center cooling systems, carry global warming potentials thousands of times greater than CO₂. While they don’t directly consume power, their leakage during service or disposal can contribute to greenhouse gas emissions.

Unlike efficiency regulations that tend to trickle in slowly, refrigerant policies are being phased in with conviction. These aren’t suggestions, they’re mandates with real procurement, servicing, and design implications. For data centers, that means cooling infrastructure is entering a state of rapid transition. And because cooling is mission-critical, every choice carries high stakes.

The Refrigerants Coming Next

With high-GWP refrigerants being phased down, the industry is turning to alternatives. The most promising options fall into three broad categories.

Hydrofluoroolefins (HFOs) like R-1234yf and R-1234ze are current front-runners for their ultra-low GWP ratings (less than 10), but they introduce mild flammability risks. HFO/HFC blends, such as R-454B and R-513A, offer transitional solutions with more familiar handling
characteristics. And natural refrigerants, including CO₂ and ammonia, represent the greenest chemical options, though they come with unique design and safety challenges that often make them unsuitable for indoor or hyperscale environments.

Here’s the catch: there is no one-size-fits-all answer. Each alternative changes the game, from thermodynamic behavior to service protocols to fire safety requirements. The move away from legacy refrigerants is not just a chemical switch. It demands new thinking across the mechanical, electrical, and controls disciplines.

Designing for a New Kind of Risk

The physical properties of low-GWP refrigerants, especially those in the A2L class, bring unfamiliar engineering constraints. Most are mildly flammable, meaning system leaks could introduce an ignition hazard if not properly mitigated.

This fundamentally alters how data centers need to be designed.

Mechanical rooms that once prioritized accessibility and routing now require active ventilation, gas detection, and automated isolation logic, all tied directly into the building management or control system. Controls platforms must not only monitor pressure and temperature but actively respond to leak thresholds and trigger safety protocols in real time.

When cooling circuits are indoors, refrigerant mass limits per zone may also constrain system layout. To stay under safety thresholds, operators may need to segregate cooling systems, reducing charge volume per equipment room or hallway. This affects everything from space planning and airflow zoning to piping strategy.

And then there’s the pressure. Some low-GWP refrigerants require higher operating pressures, meaning different compressors, expansion valves, and piping materials than their predecessors. Others exhibit greater temperature glide or different enthalpy curves, requiring tighter control over charge volumes and evaporation behavior to maintain efficiency. Every trade-off needs to be mapped and managed, from the mechanical plant to the control firmware.

Controls as the First Line of Defense

If refrigerants are changing and risk is rising, then smarter control systems become the safety net.

Too often, leak detection is treated as an isolated feature. But with flammable refrigerants in play, these systems need to talk to exhaust fans, main power disconnects, access control systems, and more. A control platform that treats refrigerant monitoring as an afterthought puts uptime and safety at risk.

Intelligent controls also open the door to predictive refrigerant management. By trending pressure, subcooling, and system behavior over time, operators can detect small inefficiencies or slow leaks before they escalate. This kind of insight becomes invaluable when service windows are tight and system reliability is paramount.

What Operators Need to Be Asking Now

Whether you’re designing a new data hall or retrofitting a legacy facility, now is the time to ask hard questions about refrigerant strategy. Questions like:

● Will the refrigerant in this system still be serviceable in five years?
● What are the compliance risks associated with our current spec?
● Can we segment mechanical systems to limit A2L risk exposure?
● Do our controls platforms actively manage leak detection and safety logic, or do they just passively report alarms?
● Have our service partners been trained for A2L refrigerants and their unique handling protocols?

Planning for refrigerant change isn’t just a mechanical problem. It’s a lifecycle management challenge. Future-proofing now can save years of retrofitting, revalidation, and regulatory headaches later.

Case-by-Case but Urgent for All

Some data centers, especially those built in the last two or three years, may already be compatible with next-generation refrigerants. But others may still rely on systems charged with R-410A or R-134a, and face a more immediate transition. Either way, this isn’t a distant problem.

Even if the refrigerant in use isn’t yet banned outright, upcoming service restrictions, import caps, and recycling limitations could make recharging or repairing those systems economically unviable. It’s the death of a thousand logistical cuts—not a single enforcement action—that will end legacy refrigerants.

We’re already seeing some OEMs make high-GWP product lines obsolote and accelerate design for low-GWP compatibility. Lead times and availability will likely shift accordingly. That means waiting to make a decision may shrink your options, not expand them.

Building with Flexibility in Mind

The smartest path forward is to design for refrigerant flexibility and embed readiness into your core systems.

At Airedale, we’re helping our partners do just that—with thermal platforms engineered with future legislation in mind, safety logic embedded at the edge, and BMS-integrated control frameworks that scale with regulatory complexity. From ACIS™ control systems to
A2L-compatible CRACs and chillers, we’re building for the world ahead—not the one behind.

Because cooling is too critical to get caught off guard by chemistry.

Let’s make refrigerant readiness part of the cooling conversation, before it becomes an emergency.

Want to explore what refrigerant flexibility looks like in your next project? Our team is here to help.