Patent ID: 8112860

Claim:
A glazing panel treatment method for either or both of removing contamination from an enclosed air space of the glazing panel and inhibiting ingress of contamination into an enclosed air space of the glazing panel, the glazing panel comprising at least an exterior pane and an interior pane and spacing and sealing means extending around and sealing the perimeters of the panes to form said enclosed air space therebetween, said method comprising the steps of: (i) creating an access hole in the interior pane from its surface furthest from the exterior pane, said access hole communicating with the air space; (ii) through the access hole, creating a vent hole in the exterior pane through which vent hole the air space communicates with ambient air; (iii) applying a filter means to the vent hole to filter air passing therethrough; and (iv) sealing the access hole; wherein the vent hole is located at a position lower than that of the access hole.