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Seismic Certification Impacts from Refrigerant Transition

We’ve Been Here Before

Many of us remember when the refrigerant and propellant R-22, a hydrochlorofluorocarbon (HCFC), was phased out in the USA under the Montreal Protocol due to its damaging effect on the ozone layer. HVACR (heating, ventilation, air conditioning, and refrigeration) systems using this refrigerant did not inherently emit R-22, as propellants in hairspray did, but it inevitably escaped through leaky refrigerant lines, escapes during installation and maintenance, and emissions from the landfill.

To address this issue, an HVACR industry consortium adopted the more ozone-friendly R-410A refrigerant as an alternative and its rose-colored bottle has become ubiquitous in the HVACR industry. Though it is one of many HVACR refrigerants — some chillers use R-134a and refrigeration applications have their own refrigerants — it is more common in new air conditioning applications than any other. This effort and other measures largely arrested the ozone depletion contribution of the HVACR industry but left us with a blind spot: Global Warming Potential or GWP.

Ozone layer depletion from HCFCs and other depletion agents has concentrated on the poles, where atmospheric ice enabled a greater rate of ozone depleting chemical reactions

GWP and Me

A global warming potential (GWP) value is the factor of global warming over 100 years that a certain substance will have relative to the same amount of carbon dioxide (CO2). Thus a gas with a GWP of 1,000 will cause one thousand times the global warming effect over 100 years as the same amount of CO2. The California Air Resource Board (CARB) summarizes the global warming potential (GWP) of many common refrigerants on its website. According to the Intergovernmental Panel on Climate Change’s fourth assessment report (AR4), R-410A has a GWP value of 2,088 and R-134a has a value of 1,430. R-22, still the most common refrigerant in use today, has a GWP of 1,810. While better leak protection, maintenance standards, and refrigerant recovery at end of life can reduce the emissions of these gases, additional rules have been implemented that affect the refrigerants that can be used in future HVACR equipment.

Air conditioners from most manufacturers have typically adopted R-410A with a GWP value of 2,088.

California Leads the Way

Within the State of California, the CARB has adopted regulations intended to reduce the contribution of HVACR refrigerants to climate change. This follows on decades of automobile regulations by the same agency, which caused cataclysmic changes to the automotive manufacturing industry and eventually resulted in “California Emissions Standards” being adopted for all cars and trucks being sold in the USA. In the HVACR industry, the rollout of regulations started in January 2023 with a GWP value less than 750 required of packaged terminal air conditioning (PTACs), typical in hotel applications, and packaged “window” units common in residential applications. Other air conditioning equipment manufactured in 2025 or later or variable refrigerant flow (VRF) systems in 2026 or later will also require a GWP of less than 750.

California air conditioning low GWP rollout schedule (from California Air Resource Board)

Chiller regulations go into effect January 2024. For air conditioning chillers, the GWP value of its refrigerants must also be below 750.

California chiller low GWP rollout schedule (from California Air Resource Board)

Effect on Equipment Seismic Certifications

Seismic certifications of equipment per the International Building Code and the California addenda may be affected by the refrigerant transitions, but there is no simple answer to whether new shake table testing would be required. Some new refrigerants replacing non-flammable (“A1”) refrigerants (including R-410A and R-134a) have a mild flammability (“A2L”) rating from ASHRAE causing reconfiguration of units to reduce stored volumes and increase distance from ignition sources. Other refrigerant transitions may cause new compressors, refrigerant lines, expansion valves, and condenser coils to be modified to meet the thermodynamic requirements of the new refrigerant. Such changes are sure to trigger new shake table testing since the outcome can only be characterized as a new product line.

New shake table testing is not typically required if all of the following apply:

  • Drop-in refrigerants with the same flammability rating (such as A1) are used and no reconfiguration of form factor is necessary. R-513A is a typical drop-in refrigerant for replacement of R-134a.

  • Equipment subcomponents, such as compressors, are unchanged or, if changed, meet one of the exceptions 5, 6, and 7 of CBC 2022 Section 1705A.14.3. These would include subcomponent changes to compressors, pumps, motors, or any component under 10 lbs. if 1) they have equivalent function, 2) similar supports and attachments with similar stiffness, 3) the same attachment location, 4) mass and center of mass locations not more than 10% different, and 5) are manufactured under an ISO 9001 certified process.

New shake table testing is typically required if any of the following apply:

  • When the configuration of components is materially altered, such as to comply with flammability safety requirements for A2L refrigerants

  • When new subcomponents greater than 10 lbs in weight are more than 10% heavier, 10% higher center of gravity, are mounted differently than before, or are manufactured by a non-ISO 9001 certified supplier.

  • When there is a new form factor accommodating the revised product design

Air conditioning equipment, such as chillers and other refrigerant-based systems, have varying timeline for low GWP refrigerant transition

Nationwide Regulations Coming

Even outside of California, the EPA has proposed (page 143) a lower GWP threshold of 700 to be implemented a year later, January 1, 2025, for air conditioning chillers. Residential and light commercial AC and heat pump systems other than VRF (variable refrigerant flow) are to transition to refrigerants below 700 GWP at the same time as California — January 1, 2025 — as are most VRF systems (January 1, 2026). Although the HCAI OSP program is only applicable to California healthcare facilities, seismic certification is a nationwide rule in Seismic Design Categories C, D, E, and F, so the same impact to seismic certification is expected to apply to a wide array of products and projects.

It is clear that the HVACR industry has been an innovative ecosystem since the invention of modern air conditioning in 1902. To address the significant climate impacts of its refrigerants, the refrigerant and equipment manufacturers will continue to evolve ahead of the regulations . Seismic certification is one of many approvals required of these products and it is clear the manufacturers will rise to the challenge to keep high quality, resilient, efficient, and climate friendly products on the market.

Contact Pre Compliance for More Info

To get new products listed on an OSP or seismic certification, please contact us at or 541-241-2310 to find out if we can get the new products listed without new testing. Pre Compliance engineers are able to revise OSP listings even if we were not the original engineer of record.

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