User`s guide

Model 451126 Version 1.6 February 2004
13
Useful Equations and Conversions
Area equations
Cubic equations
CFM (ft
3
/min) = Air Velocity (ft/min) x Area (ft
2
)
CMM (m
3
/min) = Air Velocity (m/sec) x Area (m
2
) x 60
Units Conversion Table
m/s ft/min knots km/hr mph
1 m/s 1 196.87 1.944 3.6 2.24
1 ft/min 0.00508 1 0.00987 0.01829 0.01138
1 knot 0.5144 101.27 1 1.8519 1.1523
1 km/hr 0.2778 54.69 0.54 1 0.6222
1 mph 0.4464 87.89 0.8679 1.6071 1
R
W
H
Area = W x H
Rectangular Duct
Circular Duct
π
R
2
A=
(A= 3.14 x R x R)