What must be present on suction lines according to regulations?

Suction lines in refrigerant systems are critical components that transport refrigerant from the evaporator back to the compressor. According to regulations, these lines require both insulation and a vapor retarder to prevent the formation of condensation on the outside of the pipes.

The presence of R-4 insulation is essential because it helps maintain the temperature of the refrigerant, ensuring efficient operation and minimizing energy losses. This insulation also prevents condensation on the exterior of the suction line, which could lead to water damage and increased humidity in surrounding areas. The vapor retarder serves to further prevent moisture from entering the insulation, ensuring that the insulation remains effective and preventing potential problems with mold or corrosion.

Overall, the combination of R-4 insulation and a vapor retarder is a specific regulatory requirement that ensures the efficiency and durability of the refrigeration system, emphasizing the importance of preventing condensation and maintaining thermal efficiency in suction lines.