Duct
·
ulator
Round & Rect Sizing
GALV. STEEL
STD AIR · 0.075
Airflow
CFM
Set any two — the other two follow.
Round diameter
Read
in Ø
Velocity
FPM
Read
Friction rate
in/100ft
Read
Nearest standard
16″Ø
Typical supply main
Rectangular equivalent
same flow & friction
Height
×
Width
18
×
inches
Actual velocity
960
FPM
Aspect
2.3 : 1