What refrigerant is used in HVAC systems?

Common refrigerants used in HVAC systems include R-410A, R-22, and R-32. R-410A is widely used in newer systems due to its efficiency and lower environmental impact compared to R-22, which is being phased out due to its ozone-depleting properties. R-32 is gaining popularity as a more environmentally friendly alternative with lower global warming potential. The choice of refrigerant often depends on system design, efficiency requirements, and regulatory standards.