A type of tubing commonly used to form evaporators and is less costly than copper is __________ tubing.

Aluminum tubing is commonly used to form evaporators because it offers several advantages. One of the key benefits of aluminum is its excellent thermal conductivity, which allows for effective heat exchange. This is particularly important in evaporator applications where efficient heat transfer is necessary to facilitate the refrigeration or air conditioning process.

In addition to its thermal properties, aluminum is also lightweight and resistant to corrosion, making it an ideal choice for evaporator construction. It provides a good balance between cost and performance compared to copper, which is traditionally used in many applications but is significantly more expensive. The affordability of aluminum tubing allows manufacturers to reduce production costs while still maintaining effective functionality in HVAC systems.

While other materials like PVC, steel, and rubber have their own applications, they do not match the thermal conductivity and overall suitability of aluminum for evaporators. PVC is often used for different plumbing purposes, steel may not provide the same efficiency and weight advantages, and rubber is typically not used in rigid tubing applications like evaporators. Hence, aluminum's properties make it the preferred choice in this context.