View Full Version : Flex connectors

01-17-2016, 10:49 AM
Are there any guidelines for using flex connections on rectangular duct? I hate the looks but sometimes thats the easiest way on a retro-fit, and I wonder if they might help with noise? Thank you. John

03-10-2016, 02:00 PM
I don't remember if SMACNA has fabrication and installation guideline on flex connector (too lazy to look it up actually!) but in my opinion there are few reasons not to use it, and at least one big reason why you should use it;
vibration isolation. In our business, we always used it on both sides of any ducted supply or exhaust fan, it prevents direct transmission of mechanical noise and vibration to the duct work. For indoor apps we used black neoprene, for outdoor apps we used only Hypalon or Durolon, for their U.V. resistant properties. The yellow material is I think for residential applications, too light duty for commercial/industrial.
We always used to keep bulk rolls of fabric only, in black (neo.) and (white) duro or hypalon. This was to enable us to fabricate flex connectors for situations where the galvanized connector from Dynair or Durodyne was inappropriate.
Shorter answer! Yes, will allow less noise in the duct work, and does make it easier to connect between two immovable points.