R480A

R480A, commercially known as RS-20, is a lower-GWP refrigerant developed as an alternative to R134a. It is designed to provide operating characteristics and cooling performance similar to R134a while significantly reducing the climate impact associated with the refrigerant.

R480A is a zeotropic HFO/HFC blend consisting of 5% R744 (CO₂), 86% R1234ze(E) and 9% R227ea by mass. It has zero Ozone Depletion Potential and is classified A1, meaning lower toxicity with no flame propagation under its standard safety classification.

Key Characteristics

• Refrigerant designation: R480A
• Commercial name: RS-20
• Refrigerant type: Zeotropic blend
• Composition: 5% R744 / 86% R1234ze(E) / 9% R227ea
• Refrigerant families: HFO/HFC/CO₂ blend
• Safety classification: A1 – lower toxicity, no flame propagation
• Ozone Depletion Potential: 0
• Global Warming Potential: 291 (AR4 basis)
• Approximately 80% lower GWP than R134a
• Typical evaporator temperature glide: approximately 4.5°C
• Compatible with POE and PAG lubricants according to RS-20 technical documentation
• Developed as an alternative to R134a
• Automotive & Mobile Applications

R480A is promoted for use as an alternative to R134a in selected air-conditioning, refrigeration and transport applications. Its characteristics make it particularly interesting for systems where maintaining an A1 refrigerant safety classification while substantially reducing GWP is desirable.

Potential applications can include:

• Automotive air-conditioning
• Trucks and commercial vehicles
• Buses and coaches
• Agricultural vehicles
• Construction and off-highway equipment
• Marine air-conditioning
• Transport refrigeration
• Other R134a refrigeration and A/C applications

The suitability and legality of R480A must always be determined for the specific application and market before conversion.

Alternative to R134a

R480A has been developed specifically as a lower-GWP alternative to R134a. Technical data for RS-20 shows similar cooling capacity and operating characteristics to R134a, while its GWP of 291 is substantially below R134a’s AR4 value of 1,430.

One of the important characteristics of R480A is its A1 safety classification. This differentiates it from mildly flammable A2L refrigerants and can make it an interesting option for selected existing R134a applications.

Retrofit from R134a to R480A

Where conversion is technically suitable and legally permitted, an R134a system may be considered for retrofit to R480A according to an approved procedure.

A professional retrofit procedure may include:

• Recovering the existing R134a
• Recording the original refrigerant and lubricant quantities
• Inspecting the complete A/C system
• Flushing the system where required by the approved retrofit procedure
• Checking the condition and quantity of the lubricant
• Checking seals, hoses and components
• Performing vacuum and leak testing
• Charging the specified quantity of R480A
• Applying the appropriate refrigerant/retrofit identification label
• Checking high- and low-side operating pressures
• Measuring vent and ambient temperatures
• Verifying cooling capacity and overall system performance

The refrigerant charge quantity should be established according to the approved retrofit procedure rather than automatically assuming that the original R134a charge quantity is correct.

Service & Maintenance

Because R480A is a zeotropic refrigerant blend, correct handling procedures are important. RS-20 technical guidance recommends charging the refrigerant in liquid form to maintain the correct composition of the blend.

Correct refrigerant identification is also important to prevent cross-contamination between R480A, R134a and other refrigerants.

Although R480A has an A1 safety classification, technicians should always follow applicable legislation, safety requirements and equipment or vehicle manufacturer instructions.

Refrigerant should never be intentionally released into the atmosphere and should always be recovered using suitable professional equipment.

Lower-GWP R134a Alternative

With a GWP of 291, zero ODP and an A1 safety classification, R480A provides another potential option for reducing the environmental impact of selected existing R134a systems.

Its combination of lower GWP, non-flammable classification and operating characteristics similar to R134a makes R480A particularly relevant when evaluating future service and retrofit strategies for existing R134a equipment.

Any retrofit should always comply with applicable local regulations and the technical requirements and approvals relevant to the vehicle, A/C system and components.

Nunchi Climate Group provides technical training, retrofit solutions, A/C service equipment, tools and technical support for R480A (RS-20), R134a and other current and future automotive refrigerants.