Patent ID: 6113488
Filing Date: 2000-09-05
Classification: F24F

Abstract:
A method of retrofitting a ventilation system for a holding cell with a replacement security grille, the method comprising the steps of:removing an existing security grille from an existing air duct in a wall of a holding cell;providing a replacement security grille having a surface area larger than a transverse opening of the existing air duct to be covered by the replacement security grille, and the replacement security grille having an air passage surface area which at least as large as the opening of the existing air duct in the wall of the holding cell and sufficient to permit a desired number of air exchanges per hour within a holding cell;forming an enlarged plenum chamber where the existing air duct passes through the wall into the holding cell by attaching an intermediate enclosure to the wall adjacent to the existing air duct, and the enlarged plenum chamber having an air passage area which at least as large as the opening of the existing air duct in the wall of the holding cell and compatible with the security grille; andattaching the security grille over the enlarged plenum chamber such that the replacement security grille is fed by a flow of air through the enlarged plenum chamber.