AIRAH
Velocity — air
Ductwork – Supply
11.00 m/s
Ductwork – Return
6.00 m/s
3.5 m/s
2.50 m/s
Steam pipe work – Mains
30.0 to 40.0 m/s
Steam pipe work – Branches
15.0 to 25.0 m/s
Ductwork – Return (Behind R/A Grille)
3.00 m/s
Ductwork – Exhaust
6.00 m/s
Ductwork – Flexible – Supply
Neck Velocity for Supply Air Registers
2.50 m/s
Coils – Cooling
2.25 m/s
Coils – Heating
3.50 m/s
1.80 to 2.50 m/s
Air Filters
Louvres – Intake (Velocity through free area)
2.50 m/s
Louvres – Exhaust (Velocity through free area)
2.50 m/s
10.0 m/s minimum
Kitchen Hood Exhaust Duct
Door Grille (through free area)
Velocity — steam
Velocity — water
Normally water velocity in pipe work should not exceed 2.4m/s to minimise erosion
and should not be less than 0.75 m/s to ensure entrained air is transported to venting points.
Chilled Water pipe work
1.8 – 2.4 m/s
Condenser Water pipe work
1.8 – 2.4 m/s
Risers and Droppers
0.9 – 2.4 m/s
Coils – Cooling
1.0 – 1.5 m/s
Coils – Heating
1.0 – 1.5 m/s
Condensers
1.5 – 2.0 m/s
Pump Discharge pipe work
1.5 – 2.7 m/s
Pump Suction pipe work
1.2 – 2.1 m/s
Drain Pipe
1.2 – 2.1 m/s
Mains Pressure Water Service Pipelines
1.0 – 2.1 m/s
Gravity Flow Pipelines from Upper Level
Storage Tanks (Top 2 Floors Only)
0.1 – 0.4 m/s
Gravity Flow Pipelines from Upper Level
Storage Tanks (Below Top 2 Floors)
1.0 – 1.5 m/s
Note: AS/NZS 3500.1:2003 states that the maximum velocity in piping shall be 3.0m/s.
The velocity limitation does not apply to any piping that is exclusively used for fire
services whether independently served by a main, or combined with a domestic water supply.
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