Refrigerants and EU regulations for building cold rooms

Choosing a refrigerant for a cold room in Europe is no longer only a technical decision. The EU F-Gas Regulation, HFC phase-down, refrigerant safety classification, equipment design, charge limits, and long-term service availability all influence which system architecture is practical. For new cold rooms, installers and specifiers should compare lower-GWP A1 refrigerants, A2L refrigerants, CO₂/R744, and R290 where applicable before selecting components.

This guide explains the main refrigerant pathways for cold rooms in Europe and links to current Danfoss guidance on F-Gas, HFC phase-down, A2L refrigerants, refrigerant transition, and low-GWP solutions.

What does the EU F-Gas Regulation mean for cold room projects?

The EU F-Gas Regulation affects the use and availability of high-GWP refrigerants in Europe. It introduced an HFC phase-down through a quota system and includes restrictions that push the market toward lower-GWP refrigerant options.
For cold room projects, this means refrigerant choice should be evaluated early in the design process. The selected refrigerant affects component compatibility, service availability, safety requirements, system efficiency, and whether the installation is prepared for future restrictions.
Installers and specifiers should consider:

refrigerant GWP
safety classification
charge size
component compatibility
future service availability
retrofit or replacement strategy
local requirements and applicable standards

Read the Danfoss F-Gas Regulation overview

Which refrigerant options should be considered for cold rooms in Europe?

Cold room refrigerant options generally fall into several pathways:

Refrigerant pathway	Typical fit	Key design considerations
Lower-GWP A1 refrigerants	Selected existing systems, retrofit paths, or projects needing non-flammable refrigerant continuity	Check compressor approval, expansion valve setup, oil compatibility, component sizing, and regulations
A2L refrigerants	Lower-GWP systems where A2L-ready equipment and safety requirements can be met	Check charge limits, leak detection, ventilation, electrical safety, component compatibility, and local regulations
CO₂ / R744	Projects prioritizing very low GWP and a non-flammable refrigerant path	Requires CO₂-specific architecture, pressure-rated components, CO₂ controls, and trained service capability
R290 / propane	Selected compact or self-contained applications	Requires strict safety compliance because propane is highly flammable
Legacy HFC systems	Existing installed base or short-term continuity where allowed	Check phase-down rules, service availability, retrofit options, and long-term refrigerant strategy

A2L refrigerants can offer a lower-GWP path while maintaining a system design closer to conventional HFC refrigeration than some natural refrigerant systems. CO₂/R744 can be a strong option where a very low-GWP, non-flammable refrigerant path is required, but it needs CO₂-specific system design.

Additional resources:

How should installers choose between A2L and CO₂ for cold rooms?

Choose A2L refrigerants when the project needs a lower-GWP refrigerant path with a system architecture closer to conventional HFC systems, and when A2L-ready components, charge limits, safety measures, and local regulations can be met. Danfoss describes A2Ls as a practical option for installers who want to reduce GWP while keeping a conventional system design.
Choose CO₂/R744 when the project prioritizes a very low-GWP, non-flammable refrigerant and can support CO₂-specific architecture, pressure-rated components, compatible controls, and trained service capability. Danfoss refrigerant guidance identifies CO₂ as one of the natural refrigerant options used in refrigeration applications.

See the cold room system design guide for A2L components, CO₂ components, pipe sizing, and controls.

What should be checked when replacing R404A in a cold room?

R404A and R507 are under pressure in the EU F-Gas framework, and Danfoss recommends making a detailed plan to replace high-GWP refrigerants, especially R404A.

Before replacing R404A, check:

compressor approval for the replacement refrigerant
expansion valve compatibility and superheat setting
oil compatibility and service condition
evaporator and condenser capacity
refrigerant charge and system pressure
regulatory status and long-term refrigerant availability
whether retrofit or full system replacement is the better path

Learn about the HFC phase-down

Retrofit or replace: how should ageing cold rooms be evaluated?

A retrofit may be appropriate when the cold room structure and major components are still suitable, and when a compatible lower-GWP refrigerant path exists. Replacement may be the better choice when the system is old, inefficient, difficult to service, incompatible with future refrigerants, or unable to meet current safety and energy expectations.

A practical decision framework:

Retrofit may be suitable when the system is in good condition, compatible refrigerant options exist, and required components can be adjusted or replaced.
Replacement may be better when the system is old, inefficient, leaking, incompatible with future refrigerants, or unable to meet safety and energy expectations.
New-build systems should be designed around the refrigerant path early, because refrigerant choice affects valves, controls, pressure ratings, safety devices, charge limits, and service strategy.

Use the system design guide to check component compatibility before selecting a retrofit path.

What role do A2L safety requirements play in EU cold room design?

A2L refrigerants are classified as mildly flammable, so system design must account for refrigerant charge, room size, ventilation, leak detection, ignition-source control, compatible components, and applicable standards. Danfoss states that A2L systems require attention for safe installation and that installers must know the relevant regulations and standards.

For a cold room project, A2L safety checks may include:

charge limit assessment
refrigerant leak detection requirements
ventilation or mitigation measures
A2L-compatible compressors, fans, valves, controls, and electrical components
installation labeling and service access
local code and authority review

Read the Danfoss A2L refrigerants FAQ

What role does CO₂/R744 play in European cold room design?

CO₂/R744 is a very low-GWP refrigerant option and is non-flammable. It can be relevant for cold room projects where the customer prioritizes a long-term refrigerant path and the installation can support CO₂-specific design.

CO₂ systems require:

pressure-rated components
CO₂-compatible valves and controls
suitable safety devices
correct pipe and component selection
trained service capability
careful commissioning and pressure control

CO₂ can be a strong fit for larger or more sustainability-driven applications, but it should be selected as a full system architecture, not only as a refrigerant substitution.

Explore Danfoss refrigerants and energy efficiency guidance

How should cold room refrigerant planning be handled for new builds?

For new cold rooms, refrigerant planning should happen before selecting the condensing unit, evaporator, expansion valve, controller, pipework, and safety devices. The refrigerant path affects system architecture and the components that can be used.

Installers and specifiers should define:

target temperature
application and product load
room size and charge implications
refrigerant safety classification
component compatibility
energy-efficiency expectations
local regulatory requirements
service and maintenance strategy

A new cold room should be designed around the intended refrigerant path, rather than selecting the refrigerant after the main components are chosen.

Where to find more Danfoss EU refrigerant guidance

Use this page as the cold-room-specific entry point, then link to the deeper Danfoss refrigerant resources:

FAQ

EU refrigerants and cold room regulations

What components do I need for an A2L cold room?

The main components for an A2L cold room refrigeration system are the condensing unit which pumps the refrigerant around the system and expels heat to the ambient air and the evaporator or 'blower' inside the cold room which absorbs heat from its surroundings using the refrigerant all contained within the closed loop system and a range of mechanical and electronic controls to ensure reliable and safe operation. Specifically for an A2L refrigeration system all the components must be approved for use with the A2L refrigerant be used.

Which safety components do I need for an A2L cold room installation?

Safety components for an A2L cold room installation should be decided after consultation with the relevant norms and standards such as but not limited for Europe EN378, For North America ASHRAE 15, for South America ASHRAE 15 and/or ISO 5149, for India IS16678 and/or ISO 5149, for China GB9237 and/or ISO5149 and for Australia & New Zealand AS/NZ51677 and/or ISO5149.

An example of safety components but not limited to the following:

Leak detection such as Danfoss DST G54C gas sensors, forced ventilation, safety shut off valves such as Danfoss GBC M motorized ball valves, electrical isolation, audio & visual leak notification.

Which A2L-ready condensing unit supports R454C or R455A for a small cold room?

Danfoss Optyma Slim and Optyma Plus are A2L ready condensing units and can operate with either R454C or R455A.

Which low-GWP components can I use to build a cold room without changing the whole system design?

Using low GWP refrigerants such as A2L's means you can keep the same basic system design as a HFC system, however all the components must be certified A2L compatible.

Which condensing unit is better for a natural refrigerant cold room: A2L-ready HFO blend or CO₂?

The choice between using A2L, HFO blend or a CO₂ condensing units depends on the priorities:

A2L/HFO - Traditional system, low GWP
CO₂ - Higher working pressures, ultra low GWP and future proof refrigerant

Which cold room setup is most future-proof for low-GWP refrigerants and simple installation?

Using low GWP refrigerants such as A2L's for a cold room set up means you can keep the same basic system design as a HFC system for a simple installation and future proof refrigerant choice.

What components do I need to retrofit a walk-in cold room to an A2L refrigerant?

You can only retrofit a cold room to an A2L refrigerant if the original installation was installed to the correct A2L standard with A2L approved components.

If I'm switching my cold room from R404A to A2L, can I keep the existing evaporator and piping or do I need to replace everything?

When retrofitting a cold room refrigeration system the choice between using the existing evaporator or replacing it, is decided if it is approved for use with the refrigerant you will use in the new system.

We need to replace an R404A walk-in cooler in a supermarket in Germany. What refrigerant path makes most sense now: retrofit, A2L, or CO₂?

The choice between retrofit, A2L or CO₂ for a cold room is a technical, regulatory and long term strategic decision.

For a small food producer adding a new chilled room, how do I choose between A2L, CO₂, and conventional refrigerants?

The choice between using existing A1 refrigerants, A2L or CO₂ for a cold room is a technical, regulatory and long term strategic decision.

If I'm switching my cold room from R404A to A2L, can I keep the existing evaporator and piping or do I need to replace everything?

What is the running cost difference between CO₂ and HFC cold room systems?

Running cost differences between CO₂ and HFC are highly dependent on system design, ambient conditions. As a guide, the following can be used as a comparison between application, climate, and approximate efficiency.

Typical comparison

Application	More energy efficient
Cold climates (Northern Europe, UK)	Usually CO₂
Supermarkets with heat recovery	Often CO₂
Industrial refrigeration	Often CO₂ or NH₃/CO₂
Very hot climates without advanced controls	HFC may be similar or slightly better
Hot climates with modern ejector CO₂ systems	CO₂ can match or exceed HFC performance