What is R-1234yf Refrigerant and Why Is It a Better Alternative

Have you ever wondered how bus drivers and passengers stay cool on sweltering summer days? Much like the air conditioning system in your car, buses rely on advanced HVAC systems to provide comfort—but on a much larger scale and with far greater demands. These systems use a refrigerant, which absorbs and releases heat as it transitions between liquid and gas, to move heat from a place where it is objectionable (bus interior) to a place where it is not (bus exterior).

While refrigerants have evolved to meet both performance needs and environmental regulations, Bus Climate Control (BCC) proactively adopted environmentally-friendly HFC refrigerant R-134a long before regulatory deadlines. Focusing on maximizing system performance and efficiency, BCC has used a single refrigerant HFC 134a to replace both CFC R-12 and HCFC R-22 refrigerants.

Now, as the HVAC industry faces the challenge of transitioning to the next phase of refrigerants, BCC has embraced the environmentally-friendly HFO refrigerant R-1234yf, ensuring continued performance and sustainability.

BCC’s Leadership in Refrigerant Innovation

BCC is collaborating with industry experts on EPA SNAP applications to approve the next-generation refrigerant, HFO R-1234yf, for use in bus HVAC systems. The transition from R-134a to R-1234yf mirrors the automotive industry’s shift, leveraging synergies between these similar transportation sectors. BCC has already started integrating and validating R-1234yf into its HVAC-R products and systems, with plans to offer solutions well before regulations mandate the change.

Why is this important? As a leader in bus HVAC solutions, we believe it’s our responsibility to be fully prepared to provide smarter, more sustainable solutions that set customers up for success in every possible way:.

1. Enhanced Performance: R-1234yf’s thermodynamic properties allow for more efficient cooling with lower energy consumption, which is crucial for buses that must meet the demands of diverse routes.
2. Future-Proofing for OEMs: By adopting R-1234yf, bus manufacturers and operators can stay ahead of regulatory changes and maintain their competitive edge with a common refrigerant use across their automotive, van and shuttle, transit and school fleets.
3. Commitment to Innovation: When it comes to moving people safely in comfort, the stakes are high. That’s why we’re committed to helping our customers make the transition to R-1234yf while maintaining efficiency and reliability.
4. Environmental Responsibility: Sustainability is a core value at BCC. Transitioning to R-1234yf is a proactive step to reduce the environmental impact of our products and support global efforts to combat climate change.

A Timeline of Refrigerants: R-12, R-134a, and
R-1234yf

In the early days of vehicle air conditioning, R-12, commonly known as Freon-12, was the go-to refrigerant. While R-12 was effective at cooling, it came with one big problem: it was among a group of chlorofluorocarbons (CFCs) found to be contributing to the depletion of Earth’s ozone layer, a part of Earth’s stratosphere that plays a crucial role in absorbing the majority of the Sun's harmful ultraviolet radiation. This is critical because the ozone layer shields the Earth from harmful ultraviolet radiation, which is linked to skin cancer and other health risks¹.

To combat this, the Montreal Protocol went into effect on January 1, 1989, phasing out R-12 to 80% of 1986 levels by 1994 and to 50% by 1999 for developed countries²,³.

As a result, manufacturers of vehicle air conditioners and refrigeration systems transitioned to R-134a, also known as Freon-134a, Genetron 134a, Forane 134a, and Klea 134a. R-134a is a hydrofluorocarbon (HFC) refrigerant with no ozone-depleting potential. However, it introduced another problem: its high Global Warming Potential (GWP). Recognizing this, the Kigali Amendment to the Montreal Protocol was adopted in 2016 to phase down HFCs like R-134a, which intended to prevent up to 0.5 degrees Celsius of global warming by 21002.

Introducing R-1234yf, a Greener Alternative

R-1234yf, also known as Opteon YF, Solstice YF, and other brand names by various producers, is a hydrofluoroolefin (HFO) refrigerant developed as a more eco-friendly alternative to R-134a. With an ultra-low GWP of less than 1, R-1234yf significantly reduces greenhouse gas emissions compared to its predecessor. It offers the same effective cooling but with a fraction of the environmental impact. This makes it a sustainable choice for manufacturers of transit buses, coach buses, school buses, shuttles, and paratransit vehicles equipped with HVAC-R systems.

R-1234yf has been widely adopted due to its compliance with stringent environmental regulations. For example, the European Union mandated its use in all new passenger vehicles starting in 2017³, and the United States by the year 2020 (Model Year 2021) ⁴. There is not currently a set timeline for buses; however, there is American Innovation and Manufacturing Act of 2020 (AIM Act) that is managing the phasedown of HFC with a goal to reduce HFC production and use to 86% of the historic value by 2036 ⁵. Bottom line, refrigerant R-1234yf represents a major step forward in sustainable climate control.

Quick Guide to Refrigerants

Here is a simple breakdown of refrigerants over the years:

• CFC R-12: Effective but harmful to the ozone layer. Phased out under the Montreal Protocol². Commonly used between the 1940s and the 1990s.
• HFC R-134a: Ozone-friendly but with high GWP (1430). Commonly used from the mid-1990s onward. Replacement to CFC R-12.
• HFO R-1234yf: Ultra-low GWP (4) and sustainable. The preferred choice for modern vehicles².  Replacement to HFC R-134a.

Supporting OEMs Through the Transition

At BCC, we understand that adopting new technologies can be challenging. That’s why we offer end-to-end support to make the transition to R-1234yf seamless. From technical training and system design consultation to ongoing service and maintenance, we’re here to help our partners succeed.

Whether you’re in need of HVAC systems to keep passengers comfortable in any weather or managing thermal systems for electric and hybrid buses, BCC’s expertise ensures optimal performance and reliability.

Moving Forward Together

As the HVAC-R industry continues to evolve, BCC remains dedicated to leading the way. By adopting R-1234yf for bus HVAC systems, we are setting a new standard in our sustainability efforts. Together, we can create a greener, more efficient future for bus climate control.

Ready to take the next step in sustainable HVAC-R solutions? Contact BCC today. Let’s move forward—one system at a time.

References

1. Reuters Staff. "Ozone layer on road to recovery despite volcano eruption, UN weather body says." Reuters, September 17, 2024. https://www.reuters.com/business/environment/ozone-layer-road-recovery-despite-volcano-eruption-un-weather-body-says-2024-09-17/. Accessed December 16, 2024.
2. United Nations Environment Programme (UNEP). "About the Montreal Protocol." UNEP OzonAction. https://www.unep.org/ozonaction/who-we-are/about-montreal-protocol. Accessed December 16, 2024.
3. Encyclopaedia Britannica. "Montreal Protocol." Encyclopaedia Britannica. https://www.britannica.com/event/Montreal-Protocol. Accessed December 16, 2024.
4. United States Environmental Protection Agency (EPA). "snap_regulatory_factsheet_july20_2015" EPA.gov. Final Rule 20 - Protection of Stratospheric Ozone: Change of Listing Status for Certain Substitutes under the Significant New Alternatives Policy Program Accessed Jan 31, 2025.
5. United States Environmental Protection Agency (EPA). "frequent-questions-phasedown-hydrofluorocarbons" EPA.gov. Frequent Questions on the Phasedown of Hydrofluorocarbons | US EPA Accessed Jan 31, 2025.