It can get very hot inside a room with big glass windows. This is an advantage for a farmer growing vegetables in a greenhouse, but it can be uncomfortable in an office. Double glazing or special solar control glass is used to help reduce the amount of heat that comes into a building.
If the lighting in a room is right, coated glass can be used as a one-way mirror for security purposes. Those on the inside can see outside perfectly, but those on the street will just see their own reflection. Patterned glass is also used for privacy, in a bathroom window for example.
Patterned glass is made by an old method of glass-making in which the glass from the furnace is poured between metal rollers to flatten it into a sheet. The pattern is imprinted into the hot glass from the top roller.
Many different designs are possible, some quite complicated. Notice how the pattern makes it more difficult to see through the glass and that it is smooth on one side. Patterned glass is often coloured for use as decorative screens.
Many offices use coted-glass windows for security purposes.
Double glazed windows provide better insulation than normal windows. They are made from two panes of glass with a layer of air trapped between them. In winter, double glazing reduces the amount of heat that escapes and keeps the inside warm, while in summer it limits the amount of sunlight coming in, preventing a room from becoming too warm. Double glazing also reduces noise pollution in a similar way.
In office blocks, where the whole wall may be made of glass, solar control glass is often used to help keep the heat out, while still letting the light in. The glass may be coloured or coated with a thin layer of metal.
Picture Credit : Google