What Is The Best Material For Ductwork?

Your ductwork is an essential part of the HVAC system. They are the pathways through which cooled air from the AC system passes and the stale air removed. There are so many duct material options in the market, and each serves a different purpose. The option you choose may be decided based on needs such as insulation, noise reduction, moisture and condensation, and build-up.

With many duct material options in the market, the challenge is finding what serves you right. This guide will help you know the information you need and make an informed decision.


There are two main categories for ductwork material;

  • Flexible ductwork
  • Rigid or metal ductwork

Flexible ductwork

As the name explains, flexible ductwork can easily curve and offer more opportunities for fitting them in tighter spaces. They are a popular option and usually tubular and made of spring steel wire and enclosed inside a 2-ply, polymer plastic.

Flexible ductwork materials are lightweight, easy to install, and the second least expensive type of ductwork. The bendable plastic covers the metal coil, and in turn, it is surrounded by insulation. While they are easy to install, you still need to follow specific ductwork installation instructions to avoid problems and ensure the ductwork is supported properly to prevent snaking and kinks.

Ductwork materials includes rubber, stainless steel, polyurethane, silicone, PVC, neoprene-dipped polyester fabric. The best flexible air filter duct for commercial buildings in extreme climates are made from silicone, PVC, rubber, and stainless steel. They have an inbuilt resistance to heat and cooling that guarantees long-lasting productivity.  

Rubber and polyurethane are the best at abrasive resistance. However, silicon cannot handle interior damage because of extreme weather resistance. On the other hand, silicon and PVC are best at handling air and moisturized environments.

In general, flexible ducts offer the advantage of easy installation and excellent air quality. These options are also resistant to bacteria and moulds; thus, they do not demand plenty of maintenance.

Rigid or Metal ductwork

This kind of ductwork is useful for permanent HVAC systems. They are usually hardy and reliable and come in different kinds of shapes, including cylindrical and rectangular. They require special installation, including computerized design. In turn, the installation considers elements such as heat pump, air conditioner, and width-to-height ratio in a commercial building.

Under rigid ductwork, there are three more types;

Types of Rigid Ductwork

1. Sheet Metal Ducts

Sheet metal ducts have been made popular by action films where people crawl through them. There are two types of materials used for sheet metal ducts. Galvanized steel and aluminium. Galvanized steel is steel that comes with a zinc coating, this helps prevent corrosion and rust build-up.

It is also versatile enough to allow for the design of different duct shapes as installation needs demand. Galvanized steel ducts also have duct wrap, which insulates against noise. The duct wrap also helps prevent the loss of cold or hot air. The insulation thus reduces energy costs.

Aluminium metal provides an excellent option because of its lightweight nature. Aluminium sheets typically come with pre-insulated panels. The sections are attached at the seams using aluminium tape and glue.

These two materials also meet the Energy Star requirements maximizing your HVAC system longevity and energy costs.

2. Fiberglass Lined Ducts

Fiberglass ducts are sheet metal ducts but come with a fiberglass liner either internally or externally. The fiberglass lining provides sound insulation from the noise provided by the HVAC.

However, there is a risk of the fiberglass deteriorating and releasing particles in the air, which affects your health. Cleaning these ducts can be a challenge because they are easily affected by mould.                                                                                             

3. Fiber board air ducts

Fiber board air ducts consist of compressed resin boards, which are then bonded with inorganic fiberglass. They also have a foil face on the outer side, which is a barrier to air and water. Inside, the air duct is sealed to prevent the fiberglass fibers and particles from getting into the air.

Fiber board air ducts also provide soundproofing and energy-saving benefits. It is the most inexpensive type of ductwork to install. Another advantage is the flexibility it offers during installation.

Whilst this option is excellent for heating and cooling systems, it is not the best fit for ventilation systems. The reason for this is its susceptibility to mould and mildew, especially in humid climates. The surface is also rough, which can affect the efficiency of airflow.

What is best for your ductwork?

Rigid ductworks are pricier because they are more permanent fixtures. They cost more to make, move, and install.

Rigid air ducts are costly up front but save money in the long run. Flexible ducts are best for fixing trunk-and-branch AC systems which are already existing. Metals ducts are more rigid, thus only useful in creating entire HVAC systems.

Flexible ductwork is also more prone to errors during construction, which costs a lot in maintenance and replacements.

Your final decision on the best material and type of ductwork work depends on several factors. These include things like location, budget, square footage, and occupants of the building, among others. For more guidance and information on the best duct material for your case, contact us, and let us help you.