A series of 'C' language design program has been developed to demostrate the concept of Computer Aided Design (CAD) and Computer Aided Manufacturing (CAM) as well as teach many aspects of Air Pollution Control System design. Most of these programs are designed to stand alone or to accept input data from an earlier program. At the beginning, the program "expert" requires the user to enter all the data necessary in designing an air pollution control system which involve space limitation, contaminant, types of hodds, minimum indraft velocity, minimum dust conveying velocity and duct work layout. After the first procedure in "expert" program is completed., "CAD" program is used to build up a series of duct work and when the computer is "told" and confirms that the ducting designed by the user is a centralized system then computer program sizes and clculates the static pressure and total air volume needed for a particular system. At the end of the job, some engineering documentation act as output of this program is created. These output files are; the DXF file (for AUTOCAD use); the material or item sheet (for purchasing department); the result sheet (shows the result of the system) and the Plasmaestension file which can be retrieved by the software of a CNC Plasma cutter machine (PLASMA II PROGRAM from Italy).