This webinar focuses on A2L refrigerants and their impacts following the 2022 ASHRAE 15 code update. Delivered by Nick Bryant, a sales engineer, the talk begins by explaining the shift from ozone-depleting refrigerants, such as those phased out under the 1987 Montreal Protocol, to refrigerants with higher global warming potential (GWP). While this shift helped reduce ozone depletion, it contributed to increased global warming effects. The Kigali Amendment in 2016 addressed this issue by phasing down HFCs and HFOs, which are now being adopted in the U.S. to lower GWP.
A2L refrigerants were introduced as a new category because of their low toxicity but slightly higher flammability compared to A1 refrigerants like R410A and R134a. These A2L refrigerants, such as R32 and R454B, are crucial for reducing GWP, but they require new safety measures. The presentation explains how these refrigerants necessitate changes in building codes and standards, particularly under ASHRAE 15. The 2022 update is the most comprehensive in the history of ASHRAE 15, introducing guidelines on refrigerant restrictions, leak detection systems, and mitigation strategies in case of leaks.
Key points covered include the importance of leak detection systems, which must respond within 30 seconds of a leak and shut down any potential ignition sources like compressors or electric heaters. Ventilation must also be activated to disperse refrigerants and prevent fire risks. The presentation highlights the Effective Dispersal Charge (EDC), a calculation that determines how much refrigerant can safely be used in a space based on factors like occupancy type, space volume, and system design (direct or indirect).
Another significant topic is the variability in local code interpretation, where states and jurisdictions may apply the standards differently. For example, whether ventilation shafts in VRV piping systems are required is still debated. Bryan advises consulting local engineers and authorities to ensure compliance.
He then discusses the possibility of Europe banning fluorinated refrigerants due to their environmental impact, particularly their breakdown into harmful chemicals like trifluoroacetic acid (TFA) that can contaminate water supplies. If such a ban occurs, the HVAC industry might have to adopt natural refrigerants like CO2 or propane (R290), which are more flammable (A3 refrigerants). This would bring additional challenges, such as stricter safety measures, increased detection systems, and larger clearance requirements.
The webinar emphasizes the evolving landscape of refrigerant technology and building code compliance. As the industry moves toward more environmentally friendly refrigerants, ongoing updates to standards like ASHRAE 15 will be critical in ensuring safety and efficiency.