Here Section details of duct including hardwood pad (100 x100 x50 )mm MS angle( 40 X40 X 4) mm ,MS angle ,nut for anchor bolt , 4mm thick MS plate , roof insulation , concrete plinth 300 x 300 x 100 mm. This system is divided into air intake section, the heater core and air-conditioning evaporator section, for more details of Section duct download this file .