Air Shower is installed at the entrance of clean room in order to remove any dust from the garment of worker and also plays the role of an air lock room by double door system. A pulsating air stream shakes the garments of workers entering the cleanroom to remove surface lint and dust. The contaminated air is then returned through a low wall pre filter to the HEPA filters for delivery to the Pulse Jets in the side-walls and ceiling. This process provides a contaminant barrier between the gowning area and cleanroom and prevents accidental contamination due to pressure loss.