
Self cleaning glass is glass that has been treated with a thin photocatalytic coating across its surface. This coating is specially designed to be able to use the power of the ultraviolet rays of the sun to break down organic dirt. This is done through the photocatalytic effect of the coating and it loosens the collected grime from the glass.
Self cleaning glass also has hydrophilic properties. What this means is that when it rains and the rain flows down a pane of glass it can wash away the grime that has been loosened by the photocatalytic process. It is the combination of these processes that allows the conservatory glass to stay cleaner for a much longer period than glass that has not been treated in this way.
The hydrophilic nature of the coating ensures that the rain does not form droplets on the glass. This means that the water flows down the glass in a sheet and this helps to eradicate streaking while at the same time washing the grime from the glass.
With self cleaning glass the photocatalytic process carries on working in the background once the dirt has been washed off and it is this that helps the glass to dry cleanly - just as if you had used a squeegee.