Pressure Loss Calculation By Duct Ventilation - Daikin VAM Series Engineering Data

EDMMT712101

17.5 Pressure Loss Calculation by Duct Ventilation

For duct ventilators and range hoods (pressure type), exhaust ventilation is performed by all ducts. Calculation of ventilation airflow
rate at that time requires calculating duct length, number of bends, components installed outdoors, etc., in order to find the proper
ventilation airflow rate.
17.5.1 Procedures from Duct Calculation to Model Selection
VAM-HVE/HVLT Series
Calculation of the necessary ventilation airflow rate
Duct design (duct diameter, duct passage, size, and bends)
Find pressure loss
of the straight pipe
section by using
the Air Duct Flow
Resistance Chart
Find Local
Pressure Loss
by the Local
Loss Coefficient
Find pressure loss for
duct system overall
Allow leeway of 10-20 % for gained pressure loss and make
necessary static pressure
Select the model that satisfies the characteristics according to
Static Pressure and Airflow Rate Characteristics
Find the Proper Straight
Pipe Length for the duct
system overall by using
the table for Equivalent
Length of Straight Pipe
components
Find intersection by
entering Bend Pressure
Resistance to Bend Static
Pressure and Airflow Rate
Characteristics
Appendix
177