New Refrigerants: What is A2L?
You may be hearing a lot about the U.S. Environmental Protection Agency’s (EPA) new regulations regarding refrigerants, which have been a topic of significant discussion and concern. The EPA’s primary goal is to effectively reduce both the production and consumption of harmful Hydrofluorocarbons (HFCs) that contribute to environmental issues. Beginning in 2025, this shift includes requiring HVAC equipment manufacturers to transition their systems to utilize refrigerants that pose a lower Global Warming Potential (GWP), thereby promoting a more sustainable approach to cooling and heating solutions.
Hydrofluorocarbons (HFCs) are highly potent greenhouse gases that have been developed and manufactured as a replacement for previously used ozone-depleting substances. These chemicals were introduced with the intent of providing a safer alternative to protect the ozone layer. The environmental impact of these hydrofluorocarbons is assessed and measured by their Global Warming Potential (GWP), which quantifies their ability to trap heat in the atmosphere compared to carbon dioxide over a specified timeframe.
What are Hydrofluorocarbons?
Refrigerants
The current refrigerant used in the US HVAC industry is R410A. Due to new Global Warming Potential (GWP) regulations, two alternative refrigerants with a GWP lower than 700 will be adopted to replace R-410A in newly manufactured HVAC equipment. The options for these new refrigerants are R-454B and R-32.
Refrigerants are classified based on their flammability and toxicity levels. A2L encompasses refrigerants that exhibit mild flammability and lower toxicity. R-454B and R-32 are examples of A2L refrigerants.
Due to the lower flammability of A2L refrigerants compared to non-flammable options, equipment manufacturers will be redesigning their products to address mitigation requirements. Mitigation measures are now necessary in the event of a refrigerant leak. To comply with these updated standards, manufacturers will incorporate additional features such as refrigerant leak detectors and mitigation systems when refrigerant presence is detected. This includes the integration of leak sensors, control boards, and intrinsically safe electrical components.
How do these new systems work to mitigate refrigerant leaks?
Although the new A2L refrigerants have a low flammability risk, it is essential to implement safety measures. The updated leak sensors and control boards are designed to work in tandem, ensuring the system shuts down in the event of a refrigerant leak. Upon detection of a leak, the sensor signals the control board to deactivate the system and activates the blower to disperse any refrigerant, while simultaneously alerting the homeowner. The leak sensors will be positioned within the indoor coil cabinet, and the mitigation board will be located in the furnace. Factory-installed mitigation components will be included in new A2L refrigerant systems, with the option for field-installed mitigation equipment also available.
