Comparison of metal and plastic on air conditioning ducts

The duct system or ventilation of a building is essential for comfort. Without it, the building can’t be heated or cooled properly. In some regions of the United States, houses may not need heating, but do need air conditioning (which is why the vast majority of households have some type of ventilation system). However, there are many materials that can be used for the conduits, including plastic and metal. When choosing a material for replacement or repair of an installed system, it is important to know the differences and similarities between the two materials.

Metal ducts for air conditioning

Metal ducts are the most common types of ventilation systems, and are made of metal sheets that have been bent to the desired shapes. The Environmental Protection Agency (EPA) indicates that today many systems of air conditioning ducts consist of mixtures of fiberglass and sheet metal, sheet metal or some other type of plastic. The change in the composition allows the best energy conservation, reducing condensation and causing greater control of the desired temperature.

Plastic pipes for air conditioning

Plastic conduits for air conditioning are made of many materials: PVC, plastic polymers and even plastic reinforced with fiberglass. Regardless of the type of plastic used to make pipes, they work the same way as the metal. However, instead of bending metal sheets to shape, liquid plastic is poured into molds of various shapes and sizes. In addition, regardless of the composition chosen by the manufacturer, all plastic pipes are designed to withstand hot and cold temperatures commonly encountered within heating and cooling systems.


Regardless of the material chosen for the ducts, they all work the same way; they will be a transport system for hot or cold air. The air is directed through the system and released at various points leading to the building. Both types of conduits can be insulated, usually using additional plastic or glass fiber. In addition, according to the Consumer Energy Center of the California Energy Commission (Center Energy Consumption of California Energy Commission), all lines, regardless of what material they are, have the potential to develop leaks that may go unnoticed for years.


There are a few differences between the two types of air ducts, the main materials used. But according to the US Department of Energy, metal ducts tend to be less efficient because these are heated or cooled in areas without a temperature control system in the house, like the attic or basement. This results in air to be heated or cooled again by the system. However, adding proper insulation can help solve the problem.