Selecting the right refrigerant is critical for efficient HVAC unit function. Historically, CFCs were widely applied, but their harmful effect led to their gradual change. Today, a variety of refrigerants are available, each with special properties and specific applications. R-134a, a hydrofluorocarbon, persists common in vehicle air conditioning,

Polystyrene sulfonate (PSF) fiber is a versatile material known for its exceptional durability. Recent advancements in manufacturing techniques have led to the development of high-performance PSF fiber with unparalleled properties, making it ideal for a diverse range of advanced applications. These fibers exhibit enhanced thermal resistance, as wel