What’s Next for Refrigerant Management

Refrigerants are liquid or gaseous cooling compounds that absorb and transfer heat in systems such as air conditioners and heat pumps. Refrigerants allow systems to cool a space by circulating the air through the system; absorbing heat from the indoor air then releasing it as outdoor air. Refrigerants are a key component of HVAC design, as they are used as a medium to transport energy from one space to another.  The heat-carrying capacity of refrigerants exceeds other mediums like air or water, meaning refrigerant properties can be leveraged to transport more energy within a smaller pipe size than what would be required for water distribution. This increases your HVAC system’s efficiency to transport energy, while decreasing the physical space required to accommodate those systems.

Refrigerants can deplete the ozone layer (Ozone Depletion Potential, ODP) as well as linger in the atmosphere, trapping heat which contributes to global warming. Legislation and code changes prompted by the Montreal Protocol, the 2015 Paris Agreement and the Kigali Amendment have eliminated ODP refrigerants. Most recently, the American Innovation and Manufacturing Act (AIM Act) of 2020 mandates a phase down of both production and consumption of hydrofluorocarbons (HFCs) including R-410A, R-134A and R-407C by 85% by 2036. The phase down schedule started with a 10% reduction in 2022 and a further decrease in 2024 to 60% of baseline levels to step down to the 2036 target. This legislation says the EPA must phase down production and consumption of HFCs and facilitate a transition to substitute refrigerants between 2022-2036. The AIM Act and the associated federal rulings from October 2023 state that no equipment using these refrigerants can be installed after certain dates for various categories of equipment:

• Chillers: January 1, 2024
• Split Systems: January 1, 2025
• VRF: January 1, 2026

After the original federal rulings, additional rulings were provided to extend these dates by one year to allow manufacturers to produce and stockpile equipment throughout 2024 that can be shipped through the end of 2025, meaning the new set of federal phase-out dates are:

• Chillers: January 1, 2025
• Split Systems: January 1, 2026
• VRF: January 1, 2027

We will see changes to building codes, equipment sizing and refrigerant selections. Refrigerants commonly used in HVAC equipment today are part of the A1 category. We anticipate model building codes to address flammable refrigerants and adopt product safety standards before local regions and

For example, the 2021 and 2024 IMC versions require all A2L refrigerants be provided with rated and ventilated shafts when the refrigerant lines pass through two or more floor/ceiling assemblies whereas the 2018 and earlier code versions did not permit the use of A2L refrigerants whatsoever. Jurisdictions may choose to be more stringent than federal requirements. For our region, the state of Maryland has ruled to enforce the original phase out deadlines starting in 2025.

GHT’s experts will work to design highly efficient systems by reducing lift, raising the leaving chilled water temperature, right-sizing cooling systems and improving insulation where possible. They will also work with facility operations teams to maintain existing equipment to target ultimate performance and leak prevention.  Existing equipment using R-410A refrigerant will need to be serviced for years to come until those pieces of equipment reach the end of life and become due for replacement. Production of R-410A refrigerant will continue for this purpose. ​

Lastly, when selecting and specifying new equipment, GHT will work with manufacturer representatives to choose a sustainable refrigerant for the application. There will be trade-offs to review to balance performance, efficiency, equipment construction, flammability, and the toxicity of the refrigerant. A lower pressure refrigerant will mean larger equipment to do the same amount of work. It will be important to consider physical space constraints for the equipment and necessary clearances early in the design process.

GHT anticipates construction costs associated with the refrigerant changeover. For example, the additional design and installation of ventilated shafts for refrigerant risers and leak detection systems. This is especially important to consider on multi-family, hotel projects, or those with a long-split system refrigerant line length. Designers should reference the 2021 IMC for that design guidance, even if it is not the current code version in that jurisdiction. The ASHRAE Standard 15 update is reducing the RCL limit (the amount of refrigerant which can be released into a normally occupied, enclosed space) which will mean more, smaller systems as part of an HVAC design. This can have another set of architectural impacts for space planning, accessibility, and maintenance of the additional equipment. As a result, air cooled split systems and/or VRF systems may become less attractive compared to water cooled systems.

At GHT, our engineers are here to help you navigate the complexities of refrigerant changeovers with confidence. By engaging early, we ensure your selections are code-compliant, constructable, and aligned with your project’s budget and schedule. Our expertise allows us to anticipate challenges and provide solutions that keep your project on track while meeting sustainability goals. For more information or help navigating this process, reach out to Laura Morder, Energy Practice Leader at [email protected].