Which material is commonly used for making ductwork?

Sheet metal is the most common material used for making ductwork due to its beneficial properties that align well with the needs of HVAC systems. It is durable, strong, and can withstand the high pressures often found in air delivery systems. The inherent rigidity of sheet metal allows it to maintain its shape under varying airflow conditions, which is crucial for efficiency in heating and cooling.

Additionally, sheet metal is non-combustible, making it a safer option in residential and commercial buildings where fire resistance is a priority. It also provides a smooth internal surface for airflow, which helps in minimizing friction losses and improving the overall efficiency of the HVAC system.

While other materials such as plastic can be utilized in specific applications, sheet metal is favored for its performance and longevity, especially in the construction of large duct systems that require strength and resistance to physical damage.