|Float Glass for Replacement Windows|
|The base of all glass used in window applications today is float glass|
Float glass provides the base for different type of window glazing including laminated, strengthened and Low Emissivity glazing.
 Float Glass
A window's glazing is one solid sheet, or several panes, of glass. The glass in today's windows is "float glass" which was developed by the British glass manufacturer Pilkington Glass. Float glass is produced by floating molten glass on a base of molten metal, such as tin. In this way each sheet of glass comes out flat and the thickness is uniform. The manufacturing process includes a number of materials including sand, sodium carbonate, dolomite, sodium sulfate and limestone. There are different types of float glass including soda-lime glass, flat panel display glass and borosilicate glass.
 Float Glass Applications for Home Replacement Windows
Float Glass is used to make the various types of glazing. Replacement window applications often have special glazing needs and these different types of glass can be made using float glass as a base. Glazing options for home window applications include heat absorbing windows, self-cleaning windows, strengthened windows, laminated windows, safety windows, Low-E windows and tinted windows.
 Heat Absorbing Glass
Float glass is used to create heat absorbing glazing units. These glazing units are comprised of float glass to which specific chemicals have been added. The chemicals react to heat, ensuring that energy is not transmitted or deflected by the glass. The glass absorbs the heat. Heat absorbing glass windows reduce glare and brightness that would otherwise transfer through the window unit.
 Self-Cleaning Glass
Self-cleaning glass involves a coating that is spread on float glass. This coating, titania, reacts with Ultra Violet light to break down organic dirt. Once this dirt is broken down it no longer adheres to the window. After the dirt is loosened water can form a sheet on the glass and pick up the loosened dirt particles as the water runs off the glass. Self-cleaning glass is generally used for window applications that are installed in difficult-to-access spots to ensure that the windows can be cleaned.
 Strengthened Glass
Strengthened glazing units are splinter-proof glass panels in which float glass is tempered or toughened through a special treatment. The process prevents the glass from splintering when it's broken. Strengthened glass is often used in window instillations in which the sill height is low, if the window is located near a walking surface or if the window frame includes an especially large window pane. Strengthened glass includes heat strengthened float glass, annealed float glass and wired float glass.
 Laminated Glass
Laminated glass is an especially durable type of strengthened float glass. Two or more sheets of strengthened glass are bonded together with a plastic interlayer. The PVB interlayer holds the glass together if it's broken and prevents the glass from shattering. Laminated glass also provides greater sound insulation capabilities than regular float glass and blocks 99% of transmitted UV light.
 Toughened Glass
Toughened glass involves float glass which is tempered. Balanced internal stresses crumble toughened glass is broken so that it does not splinter. Toughened glass is generally included in a window panel of a door.
 Tinted Glass
Tinted glass involves applying a heat rejection film to the interior of a flat glass window pane which then reduces the amount of visible light, infrared light and ultraviolet radiation that enters through the window. Tinted glass is generally used to create privacy glass.
 Low E Windows
Low E coatings are applied to float glass to insulate the glazing panels and control heat transfer. Low E is a metallic oxide which is coated onto the surface of a float glass pane to reduce the window's U Factor by suppressing the radiative heat flow. In multi pane windows the low e coating reduces the infrared radiation flow as is moved from the warmer pane of float glass to the cooler pane. This lowers lower the window's heat transfer. Low E coatings are invisible when coated on a float glass pane.