Which material is used for air conditioning drain lines?

The correct material used for air conditioning drain lines is PVC (Polyvinyl Chloride). PVC is widely favored for this application due to its excellent resistance to corrosion and ability to withstand the varying temperatures of condensation. It is also lightweight, easy to install, and has a smooth interior surface that allows for efficient drainage of water. The durability of PVC helps ensure that it will not easily crack or break over time, making it a reliable choice for long-term use in drain systems.

In contrast, while other materials like polyethylene and ABS are also used in various plumbing applications, they may not have the same level of compatibility or durability specifically for air conditioning drains. Galvanized iron, on the other hand, is prone to rust and corrosion, making it unsuitable for environments where moisture is prevalent, such as AC drain lines. Thus, PVC stands out as the most effective and commonly used material for this purpose.