For the system shown below which made from galvanized iron which Roughness of galvanized iron & = 0.00015 m. Friction pressure drop (Ap/L) pa/m in main duct AB must be calculate by equal friction method and size duct and air velocity in each branch with using the duct friction chart. Also calculate the air fan power required. Take the followings for air .Air density p = 1.2 kg/m, air dynamic Viscosity =18.178 x10 Pa.s. The pressure drop in the Air Handling Unit ( g) is 375 Pa. Assume the velocity in the main duct GH is 8 m/s AP Air-Handling) Air Handling Unit M 2 m/s Ducts System A B Damper D Moxxing section E 7 m 10 m K 35 m L 20 m H Filter Cooling coil 7 m N 1 m/s 3 m/s Air-Handling Fan Power =Qxp Air-Handling+ 1 AP Exit -XL) Friction + Fitting Exit 2 L Note: one damper and elbow 90 in each branch of (HM,KN) and one damper in branch KL Fitting K{Fan discharge to main duct 0.3; Branch from main duct 0.4; Expander 0.75; Reducer 0.05; Standard 90 elbow 0.75; Damper 0.2; Exit grille 0.5}