What is the best way to make a duct energy efficient?

Sealing joints and insulating ducts is recognized as the best way to enhance duct energy efficiency. When ducts are properly sealed, air leaks that typically occur at joints, seams, and connections are prevented, which minimizes the loss of heated or cooled air as it travels through the system. This ensures that the conditioned air reaches its intended destination, thus improving the overall efficiency of the HVAC system.

Insulation further amplifies this effect by reducing the energy loss associated with temperature differences between the inside of the ducts and the surrounding environment. Proper insulation helps to maintain the temperature of the air inside the ducts, resulting in less energy consumption to achieve desired indoor conditions.

In contrast, while replacing ducts with metal can enhance durability and may help with certain airflow issues, it doesn’t directly improve energy efficiency unless combined with sealing and insulation. Avoiding bends can aid in airflow efficiency but doesn’t address heat loss. Similarly, opting for smaller duct sizes may create airflow challenges and could lead to a less efficient system overall. Thus, sealing joints and insulating ducts fundamentally improve energy efficiency by minimizing waste and maintaining consistent airflow.