Sono Flex Duct: Snake Oil or the Real Deal?
Posted: Wed, 2021-Jul-14, 14:44
so the silencers that i saw were "straight through" which implies the absorption panels in the flow and around the shell to provide absorption. i have no other details on their internals. i do know the ducts where about 1m in diameter in the big room, perhaps larger. the secret to all of this was constantly increasing the overall sizes to reduce the flow rate. there was no double penetration (as far as i can tell) as the rooms in Galaxy are all large concrete shells within the overall building shell. the main room weighs in at about 300 tons.
as far as a normal set of construction, there are several options: baffle boxes on each side of the mass with a flexible duct encased in mass-equiv sleeves (only really use this in loud situations), ducting which has absorption and can be passed off the main branch into each room (i like duct board for this most times) which minimal contortions, or flex duct (which i use in small places where i don't care much about the inefficiencies from drag). but always leverage the plenums in room.
as far as a normal set of construction, there are several options: baffle boxes on each side of the mass with a flexible duct encased in mass-equiv sleeves (only really use this in loud situations), ducting which has absorption and can be passed off the main branch into each room (i like duct board for this most times) which minimal contortions, or flex duct (which i use in small places where i don't care much about the inefficiencies from drag). but always leverage the plenums in room.