A tight back-to-back 45-degree S-offset is noisy and dropping pressure
Tight back-to-back offsets can make high-velocity air separate from the throat. Open it up, lengthen it, add approved vane/detail, or revise the fitting path before blaming the unit.
Do not treat a noisy tight offset as normal if it is creating a measurable pressure or airflow problem.
Check
Listen for wind noise at the offset during startup.
Check if the travel piece is extremely short.
Look for high velocity, pressure drop, or TAB complaint.
Confirm whether vanes are allowed for that fitting and pressure class.
Consider longer offset or revised path before final seal.
Steps
Listen for wind noise at the offset during startup.
Check if the travel piece is extremely short.
Look for high velocity, pressure drop, or TAB complaint.
Confirm whether vanes are allowed for that fitting and pressure class.
Consider longer offset or revised path before final seal.
Say this to your foreman
The tight back-to-back 45 offset at [location] is noisy and may be dropping pressure. I checked the travel length and fitting path. Do you want this lengthened, revised, or detailed with approved vanes?