Notes) In case of 90°bend in the minimum bending radius, the length of the notation will be added as a pressure loss.
Equivalent straight length of the pipe (mm)
To calculate the duct pressure loss, please refer to the ventilation quality of each manufacturer.
example) using the duct in the above mentioned characteristics figure
φ150mm, the pressure loss when the air volume 10m3/min is ventilating in the duct of length 3m
However, we assume that there is a 90 ° bend in the middle one time.
From the special graph, the pressure loss of the straight tube is approximately 12Pa/m.
equivalent straight tubular length of 90° bend is 900mm
Pressure loss = 12×(3+0.9)=46.8(Pa)