Benefits of Using Low-GWP Refrigerants in HVAC and Water Heater Systems

Efficient and essential strategy for decarbonization

Refrigeration and air conditioning equipment generate approximately 7.8% of global greenhouse gas emissions. Of this 7.8%, 37% comes from the release of refrigerants into the atmosphere.¹ Transitioning to low-GWP refrigerants is an efficient and essential refrigerant decarbonization strategy.

Global Warming Potential (GWP)

Global Warming Potential (GWP) is a metric used to establish how much heat a refrigerant traps in the atmosphere within a 100-year time period.2 The lower the value, the less heat a refrigerant will trap during its life cycle, which includes recovery, reclamation, disposal, and leaks in the refrigeration loop. Low GWP is defined at a threshold of 750 GWP or less. This requirement starts taking effect in Jan 2024.

Where refrigerant R-410A has been used in the past, manufacturers are typically switching to R-32 and R-454B. For R-134A refrigerant, they are typically switching to R-513A, R-1233ZD, and CO2. Updating a system to low GWP is not a drop-in replacement. It often requires additional modifications and considerations. There is not one universal replacement and replacement refrigerant may vary based on the manufacturer.

Main refrigerants at play

The graph below shows the relationship between lower GWP refrigerants values and density (pressure) of main refrigerant groups to when considering capacity needs and products that may meet your project needs.

Regulation and code requirements

California regulations are leading the charge on low-GWP refrigerant alternatives. The California Air Resources Boards’ (CARB) main goal is to develop regulations and rules to fight climate change and prevent air pollution. They have issued a regulation in regard to Low GWP (CARB Ruling). Per their requirements, various equipment will be required to have Low GWP refrigerants in the coming years. See the table below for current effective dates and applicable equipment.

In addition to CARBs state-level requirements, the American Innovation and Manufacturing (AIM) Act was passed in 2020 authorizing the US Environmental Protection Agency (EPA) to phase down production and consumption of HFCs (Background on HFCs and the AIM Act | US EPA). The SNAP Proposed Rule 23, also issued by the EPA, has additional information on approved refrigerants for residential and light commercial AC uses in new equipment.

Current effective dates and applicable equipment

• Jan 1, 2023: New PTACs, PTHPs, and room/window ACs can no longer use a refrigerant with GWP > 750
• Jan 1, 2024: New chillers for air conditioning can no longer use a refrigerant with GWP > 750
• Jan 1, 2025: New split AC and heat pump equipment can no longer use a refrigerant with GWP > 750
• Jan 1, 2026: New VRF equipment can no longer use a refrigerant with GWP > 750

What are the benefits?

• The primary advantage of low-GWP refrigerants is that over its lifetime (which includes production, transportation, reclamation and recycling, storage, and disposal). It traps less heat in the atmosphere, therefore reducing their carbon footprint.
• Developing Refrigerant Management Plan: CARB requires owners and operators of refrigerant systems with more than 50 pounds of 150+ GWP refrigerant to develop and report RMP with maintenance and service records.
• Currently CO2 is a natural refrigerant with a GWP of 1, making it a great option. Based on the current scale of refrigerants this is the least harmful to the environment and supports CARB’s target of reducing HFC emissions 40% below 2013 emissions levels by 2030 which contributes to project teams’ net-zero carbon goals.

What are the challenges/constraints?

• Tend to have a higher flammability potential than current standard practice refrigerants
• Could be a challenge based on availability in the market but below are some alternatives that are coming to the market
• Traditionally Low GWP are less efficient so will need a slightly larger machine (more pounds of refrigerant for the same capacity). Refrigerant cannot always be traded out pound-for-pound, system needs to be configured for Low GWP. Components of design are NOT interchangeable.
• Parts that must be designed specifically for the low-GWP refrigerant:
  • Compressor
  • Expansion valve
  • Electrical components
  • Refrigerant charge size
• If using CO2, the system will have to operate at much higher pressure than traditional refrigerant. This higher pressure requires more safety mechanisms, higher cost of service/maintenance due to higher cost of parts, more trained service people required, etc.

Lower-GWP alternatives for residential and commercial AC^a

Low GWP refrigerant is an important element in decarbonizing California. On top of it being a step in the right direction for our environment, implementation of Low GWP refrigerants is becoming a requirement for various HVAC equipment over the next few years. There is still development and research continuing as we make this transition to better refrigerants. Talk with your manufacturers and suppliers for more information on offerings and availability. Options will vary by manufacturer.

Contact us for information on available inducement in the CEDA program.

Sources

• ACHR News, The 2023 Refrigerant Transition: What You Need to Know The 2023 Refrigerant Transition: What You Need to Know – YouTube
• AiCARR, Low-GWP Refrigerants and their Role towards Decarbonization (Apr 13, 2022)220413_LOW GWP REFR_PROGRAMME.pdf – AiCARR.org
• Chemours, Ride the Refrigerant Wave from R410A to R454B WebinarRide the Refrigerant Wave from R-410A to R-454B Webinar – YouTube
• EPA, Transitioning to Low-GWP AlternativesTRANSITIONING TO LOW-GWP ALTERNATIVES in Residential and Commercial Air Conditioning and Chillers – EPA.gov)
• EPA, Understanding Global Warming PotentialsUnderstanding Global Warming Potentials – EPA.gov
• PG&E, Next Generation Refrigerants Webinar (Mar 1, 2023)PG&E Energy Education Classes – docebosaas.com
• Trane, R454B refrigerant on scroll unitsPowerPoint Presentation – tranebelgium.com
• CARB, The Road to Zero EmissionsCalifornia Air Resources Board homepage

¹ Source: AiCARR’s Webinar, Low-GWP Refrigerants and Their Role towards Decarbonization
² Source: EPA, Understanding Global Warming Potentials (https://www.epa.gov/ghgemissions/understanding-global-warming-potentials)