What is the difference between an Air Duct and Air Connector?
Both Air Ducts and Air Connectors are tested per the UL 181 standard. Air Ducts are required to pass fifteen (15) UL 181 tests whereas an Air Connector is only required to pass twelve (12) tests. Air Connectors are not required to pass UL-181 impact, small scale flame penetration or impact tests. As a result, Air Connectors can only be installed in lengths of up to 14 feet. There are no installation length restrictions on Air Ducts.
How can I tell the difference between an air duct and air connector?
In many cases Air Ducts and Air Connectors look similar in appearance. The only way to truly distinguish between the two products is to examine the label on the product. An Air Duct has a rectangle or square within the label whereas the Air Connector will have a circle within the label (shown below in red). The words “Air Duct” or “Connector” will also be specifically referenced on the label (see blue arrow below). All JPL Air Ducts & Air Connectors are rated Class I having a FHC of 25/50.
FYI – Air Connectors can be produced with or without fiberglass insulation and vapor-barrier. JPL has not observed any non-insulated Air Connectors in the USA during the last 20+ years.
The above labels are actual JPL labels & product nomenclatures