APPLIED THERMAL CONT
TRANSITIONING TO LOW-GW
PROCESS COOLING
The transition to low Global Warming Potential (GWP) refrigerants is reshaping the process cooling landscape.
Driven by tightening environmental regulations and sustainability targets, engineers and manufacturers are increasingly required to move away from traditional high-GWP refrigerants toward more environmentally responsible alternatives.
Among the most widely adopted options in process cooling are R290 (propane) and R454C, each offering distinct advantages and trade-offs. In practice, the selection of these refrigerants is often driven by system capacity and application requirements, rather than a direct like-for-like choice between the two
This white paper explores:
The characteristics of R290 and R454C and how they are applied in different system sizes
Key regulatory drivers across major regions (UK, EU, US, UAE) Application considerations when selecting low-GWP refrigerants
It is intended to support engineers, OEMs, and technical decision makers navigating this transition
The Challenge
Transitioning to low-GWP refrigerants is not simply a case of replacing one refrigerant with another. Each alternative introduces new considerations around safety, system design, performance, and compliance. In many cases, there is no single “like-for-like” replacement, meaning engineers must balance environmental impact with practical system requirements Understanding these trade-offs is essential to making informed decisions.
APPLIED THERMAL CONT TRANSITIONING TO LOW-GW
R290 and R454C i
R290 and R454C are both low-GWP application suitability Rather than chiller capacities and system desig considerations
R290
R454C
R290 is a natural refrigerant with extremely low environmental impact Key characteristics include:
Ultra-low GWP ( 3)
Excellent thermodynamic performance
High energy efficiency
Advantages of R290
Superior heat transfer performance
Environmentally sustainable
High system efficiency
Future-proof against regulatory changes
Limitations of R290
Classified as A3 (highly flammable)
Charge size and limitations in many applications
Requires strict safety design and risk assessment
May require additional safety components and certifications
R454C is a synthetic, mildly flammable refrigerant blend designed as a lower-GWP alternative to traditional HFCs. Key characteristics include:
Low-GWP (~148)
Lower flammability compared to R290
Advantages of R454C
Easier transition from legacy refrigerants
Lower flammability risk compared to A3 refrigerants
Suitable for a wide range of applications
Limitations of R454C
Higher GWP than natural refrigerants
Lower efficiency compared to R290 in some applications
Still subject to long-term regulatory pressure
Performance Com
When comparing R290 (propane) a distinct advantages depending on t
R290 provides excellent thermodyn strong cooling capacity, high energ support compact system designs and lower power consumption.
R454C, meanwhile, offers a balanced combination of performance, lower GWP, and reduced flammability classification (A2L), making it well suited to larger systems and applications where refrigerant charge, installation environment, or regulatory compliance are key considerations
While R454C can experience a greater reduction in cooling performance at more demanding lowtemperature conditions compared with R290, it remains an effective and widely adopted solution for medium and large-capacity chiller systems Conversely, although R290 can deliver very strong performance and efficiency benefits, its A3 flammability classification requires additional design considerations around ventilation, leak detection, electrical protection, and overall system compliance.
As such, we utilise R290 within our smaller chiller platforms, where refrigerant charge limits can be more easily managed, and R454C within our larger chillers, where system capacity and application requirements make it a highly practical and effective solution
Selection Considerations
In general:
R290 is typically applied in smaller-capacity systems where maximum efficiency and ultra-low GWP can be achieved within charge size limitations
R454C is typically applied in larger-capacity systems where lower flammability classification and practical system design considerations are key.
Regulatory Driver
UK & European Union
The UK and EU are implementing phased reductions in high-GWP refrigerants under F-Gas regulations. Key drivers include:
Gradual reduction in allowable HFC quotas
Restrictions on placing high-GWP systems on the market
Increasing compliance requirements for manufacturers
Direction of travel:
Continued tightening of GWP thresholds
Increased focus on natural refrigerants
Greater emphasis on lifecycle emissions
United States
United Arab Emirates
Regulation in the US is evolving, with increasing adoption of low-GWP refrigerants driven by federal and state-level initiatives
Key influences include:
The AIM Act (American Innovation and Manufacturing Act)
State-level regulations (e g California)
Industry-led sustainability commitments
Greater emphasis on lifecycle emissions
The UAE is also aligning with global environmental goals, with increasing focus on reducing emissions and improving energy efficiency
Key drivers include:
Adoption of international standards
Sustainability initiatives and green building regulations
Gradual transition away from high-GWP refrigerants
Regional Differences
Global refrigerant regulations all aim to reduce highGWP refrigerants but differ in pace and structure
The EU is the most stringent, using a quota-based phasedown with explicit bans that rapidly push adoption of very low-GWP refrigerants
The US follows the AIM Act with a federally driven phasedown but varied state-level rules that create regional differences, and Asia applies a more mixed approach, with Japan and China implementing staged reductions under the Kigali framework but generally with more gradual timelines and greater flexibility in refrigerant choice.
Impact on System Design
Regulations influence refrigerant selection, system architecture, safety requirements, and future upgrade pathways,
Application Consi
Selecting the right refrigerant depends heavily on the application and operating environment
Safety Requirements
System Design Implications
Flammability classification plays a critical role R290 is classified as an A3 refrigerant, meaning that it requires strict safety measures including leak detection, ventilation, and explosion protection in certain environments R454C poses a lower flammability risk as an A2L refrigerant but still requires compliance with safety standards
Different refrigerants require different system designs, including:
Component selection
Refrigerant charge management
System layout and enclosure design
Charge Size Limitations
Performance Requirements
Environmental Conditions
R290 systems are often limited by maximum allowable charge sizes This can influence system capacity and application suitability and may require distributed or modulated designs
Applications with high cooling demand or efficiency requirements may favour refrigerants with better thermodynamic performance, such as R290
Ambient temperature, installation environment, and application type all influence refrigerant selection
Common Challen
Safety Concerns
Flammability introduces additional requirements.
Lack of Familiarity
Engineers and end users may be les refrigerants
System Redesign Requirements
Existing systems may not be directly combatible with new refrigerants
Regulatory Uncertainty
Future regulatory changes can make long-term planning challenging
Balancing Sustainability & Practicality
The lowest GWP option is not always the most practical Trade-offs between efficiency, safety, and cost must be managed
Best Practice Approach to Transitioning
Understand Regulatory Requirements
Ensure compliance with current and future legislation in target markets
Define Application Needs
Consider cooliing capacity, environment, and safety constraints.
Evaluate Refrigerant Options
Assess refrigerants such as R290 and R454C based on GWP, performance, safety, and suitability for the intended system capacity and application
Assess System Design Implications
Ensure system design aligns with refrigerant properties.
Plan for the Future
Chiller selection is increasingly shaped by lower-GWP regulations, with R454C and R290 used according to application size,safety requirements, and long-term compliance needs.
Practical Recomm
Prioritise low-GWP refrigerants
Carefully assess safety implicat refrigerants
Avoid assuming direct replacem
Engage with technical specialis
Consider long-term regulatory and environmental impacts.
The transition to low-GWP refrigerants is a necessary and ongoing shift in the process cooling industry
By understanding the characteristics of refrigerants such as R290 and R454C, and how they are applied across different system sizes and applications, recognising the impact of global regulations, and carefully considering application requirements, engineers can make informed decisions that balance performance, safety, and sustainability
A proactive approach to refrigerant selection ensures compliance while supporting efficient and reliable system operation
To discuss how these considerations apply to your specific application, or to explore suitable low-GWP chiller solutions, get in touch with our team or visit our website for more information.