What are flexible duct connectors?

A flexible duct connector is an airtight, flexible connection consisting of a fabric fixed to sheet metal on both sides.

Why use flexible duct connectors?

Flexible duct connectors are used as a link between equipment and ductwork to isolate vibrations and noises in a duct system. Flexible duct connectors, unlike rigid duct, allow a slight offset between equipment and ductwork.

In which market segments are flexible duct connectors used?

Flexible duct connectors are manufactured in various sizes and thicknesses for use in residential, light commercial, commercial and industrial applications.

Why is the fabric-to-metal joining method important?

Answer. You want a permanent, airtight connection. The type of joint used will also affect the structural rigidity of the connector. There are many flexible duct connectors available with a wide variety of joining methods.

Manufacturers use double fold offset stitching on all of our flexible duct connector products. This joint style ensures that you have an airtight seal that will not be damaged when the connector is formed into its final shape. The double fold offset stitching also adds structural stability to the connector, which means that the connector will not fail due to over or under pressure issues.

Is the metal used important?

Yes, metal makes up two thirds of the flexible duct connector.

Assembly is therefore the key to a long-lasting connection. The metal used in standard flexible duct connections is galvanised steel. When looking at galvanised steel you should consider the coating thickness and how this affects the life of the metal, and the installation location. The two most commonly used galvanised steels in HVAC are marked G60 and G90. 60 and 90 refer to the total amount of zinc deposited on the surface of the steel;

G90 has a thicker coating and therefore lasts longer. In indoor applications, G60 will have two-thirds of the life expectancy of G90, which means that the indoor life expectancy of G90 is 20 years longer than G60. For outdoor applications the full life expectancy drops significantly, but you will still see the G90 outlast the G60. SMACNA (Sheet Metal and Air Conditioning Contractors National Association) recommends using a minimum of G60 for duct and connectors in its “Duct Construction Standards – metal and Flexible” standard. While G90 is not required according to SMACNA, we understand the need to produce a quality product that standardises on G90 for all our duct connectors and has a long life.

Does a flexible duct connector affect airflow in the duct system?

A properly installed flexible duct connector will not impede airflow through the duct system. It is important to size and fit the flexible duct connector to suit the distance the fabric will be spread. If the fabric is allowed to sag or accordion too much, it can affect the airflow through the connector.

How do I choose the right flexible duct connector?

There are several key factors that will determine which flexible

duct connector is right for your job. At what pressure will the duct system operate? Will the equipment be installed inside the building envelope or outside the building? What are the typical minimum and maximum temperatures the duct system will be exposed to? Will the flexible duct connector be exposed to additional components in the air stream (chemicals, etc.)? How large a distance do you need to cover? These are just a few of the important factors to consider.