4 HVAC Duct Types Used in Heating and Cooling

Ductwork is the hidden backbone of your home’s HVAC system. While you may not be familiar with all the HVAC duct types that are out there, it helps to know which variety is in your home or which type works best should you need a repair or complete replacement.

1. Flexible

Flexible ductwork consists of a metal wire coil covered by a layer of plastic. Its thermal insulation is made of glass wool, which helps reduce heat loss or gain and improves energy efficiency. This type of ductwork is commonly used in smaller, single-story homes with tight spaces. 

Best for: Smaller homes with tighter budgets

2. Sheet Metal

As its name suggests, sheet metal ductwork is made of galvanized steel, aluminum, or stainless steel. This type of ductwork can be shaped into round, spiral, or rectangular ducts and is one of the most durable types available. It falls on the higher end of the price range due to its ability to resist mold and pests. 

Best for: Larger homes in humid or extreme climates 

3. Fiberboard

This ductwork type consists of compressed resin-bonded fiberglass topped with a foil laminate to prevent moisture buildup and leakage. Because of its rough material, it can be prone to trapping dust and debris, so it helps to consider the cost of air duct cleaning if you’re thinking about installing fiberboard ductwork.

Best for: Small homes in moderate climates 

4. Fiberglass Lined 

Fiberglass-lined ductwork is made of sheet metal ducts coated with a layer of fiberglass insulation. It’s beneficial for open spaces that need noise control and more consistent thermal control.

The main downside is that it’s possible for fiberglass-lined ducts to deteriorate and release small particles of fiberglass into the air, which can be harmful for people who struggle with breathing conditions like asthma.

Best for: Commercial buildings or offices

Choosing the Right Ductwork

Don’t try to climb up into an attic to learn more about duct systems. A local ductwork installer can take a look at your home or plans for your home to make recommendations on the right type of ductwork for you. HVAC ductwork can make the difference between a well-heated home or one that harbors mold and has you shivering in below-freezing temperatures.