EPA’s Updated HVAC Requirements Take Effect

A new class of refrigerants has emerged in the HVAC industry, as mandated by the American Innovation and Manufacturing Act of 2020. It mandates that 85% of the existing hydrofluorocarbons (HFCs) in HVAC units be phased down by 2036 and replaced with new refrigerants, referred to as A2Ls, which have a lower global warming potential (GWP) than current classes.

New Requirements 

Remodelers installing new air conditioners need to be aware that as of Jan. 1, 2025, the U.S. Environmental Protection Agency requires newly manufactured HVAC equipment to use A2Ls. Air conditioning equipment manufactured or imported prior to this date has a one-year grace period through Jan. 1, 2026. Existing equipment is not subject to EPA regulations and can continue to be used through equipment end-of-life.  

The newest A2L refrigerant, R-454B, will gradually replace the current refrigerant, R-410A. The new A2L retains the same toxicity designation (non-toxic) as its predecessor, but R-454B has a 78% lower GWP than R-410A. However, the R-454B flammability level is Class 2L (lower flammability), slightly higher than R-410A, which is Class 1 (no flame propagation). 

To address the slight increase in flammability, equipment manufacturers have updated installation instructions, added new safety features, and revised transportation and handling procedures.  

To prevent refrigerant leaks, preliminary mitigation measures require enhanced testing of refrigerant lines using both pressure and vacuum methods, specific joint types, and nail plates at framing members where lines are running through. Decreasing the level of refrigerant concentration in a building to below the flammability limit can also minimize potential leakage. 

In many cases, equipment manufacturers will install a leak detection sensor in the air handler unit, programmed to activate the main fan to circulate the air throughout the home to reduce refrigerant concentration. For systems without leak detection sensors, the quantity of the refrigerant in the system, including the lines, will need to be carefully sized in order to prevent refrigerant leaks in small spaces where the concentration could exceed its limit. Other safety strategies include the use of shut-off valves activated by leak sensors and designed to limit the quantity of refrigerant that can leak out. 

Redesigned HVAC Equipment

The transition to R-454B has resulted in the redesign of current HVAC equipment. It is important for remodelers to actively communicate with vendors and installers about new installation techniques and establish a switch-over timeline of existing and new HVAC systems. Once the switch occurs, existing and new equipment will not be compatible unless stated by the manufacturer.  

Remodelers should coordinate with the mechanical system designer, especially in instances where a fire-rated shaft might be required in a multifamily building. At the beginning stages of installation, remodelers should ensure that their HVAC contractor is familiar with the new installation requirements and safety measures for the new HVAC equipment. 

Short-Term Challenges

R-454B has been in high demand since January, and shortages have been reported. However, the brief spike in demand was partially due to hoarding driven by concerns over tariffs, and the situation is expected to be resolved soon. Refrigerant manufacturers have ramped up production, and supply is expected to stabilize.  

Analysts do not anticipate the short-term shortages to lead to long-term disruptions. The National Association of Home Builders is monitoring the situation and will alert members to any potential issues that might affect construction activity.