Rigid vs Flexible: Which One Is Best for Your Ducted HVAC System?

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If you plan to install a ducted HVAC system, your choice of ducts can make a huge difference to the system's efficiency. Energy efficiency, comfort levels, indoor air quality, cost-effectiveness, etc., are several reasons why having good ductwork is important. Generally, the two primary ductwork categories are flexible and rigid ductwork. As the name implies, flexible ducts can snake easily through tight spots. They are typically made from non-metallic materials like PVC, rubber and silicone.

On the other hand, their rigid counterparts are made from metal and can be cylindrical or rectangular. There are pros and cons to installing either type. Therefore, here is a guide to help you decide which one between the two is the best for you.


Ductwork installation can be expensive. Therefore, understanding the costs of each type will come in handy for your budgeting. Generally, rigid ducts are more expensive than their flexible counterparts. That's because they are typically made from more durable materials. In addition, metal tends to be heavier than most materials used to make flexible ducts. Installing a metal or rigid ductwork can also be more labour-intensive and complex, especially in tight spots. Therefore, your labour or installation costs will likely be higher if you decide to use rigid ducts.


Rigid ducts may be expensive upfront. However, the extra costs will pay off in longevity. That's because these ducts will often last longer than their flexible counterparts due to them being made from stronger materials. Therefore, they are less prone to leaks and punctures like their flexible counterparts.


Installing flexible ducts is typically easier and faster. That's because they are more flexible and lighter, making them easier to work with. Their non-rigid nature also makes them easier and faster to install in tighter spots and confined spaces like wall cavities and cabinets.

Air Resistance

Proper airflow in your ducts is critical to your HVAC system's efficiency. Therefore, you need an unrestricted flow of air inside your ducts to ensure you get the most of the cooled or heated air in your rooms. In addition, poor airflow can make your system work harder than it should to cool or heat your space, resulting in poor energy efficiency and increased energy costs. Generally, flexible ducts create more airflow resistance than their rigid counterparts. Their design allows for more crumpling and bending, particularly in sharp sections and turns that may restrict airflow. On the other hand, rigid ducts maintain their shape, reducing airflow resistance.

Keep these HVAC ductwork installation tips in mind when looking for local services.