What is a typical method for insulating ductwork?

Fiberglass insulation is a typical method for insulating ductwork because it provides excellent thermal resistance, which helps to reduce energy loss in heating and cooling systems. This type of insulation is lightweight, relatively easy to install, and effective in minimizing heat transfer to and from the ductwork. It helps maintain the desired temperature of the air flowing through the ducts, which is crucial for enhancing the overall efficiency of HVAC systems.

Moreover, fiberglass insulation also offers sound dampening properties, which can help reduce noise transmitted through the ducts. Proper insulation of ductwork is essential not only for energy efficiency but also for providing a comfortable indoor environment, making fiberglass a popular choice among HVAC professionals. The other methods listed do not offer the same level of thermal performance or practicality for duct insulation as fiberglass does.