GLASS IN ARCHITECTURE
Glass is an essential element of the building in order to allow light inside. To make the most of this important feature, contemporary architecture favours large size windows. The technology of glass, known since ancient times and exploited in the building industry since the Roman era, has experienced during the last 50 years a great evolution in terms of production and transformation technologies.
Glass is today an essential element for the thermal and acoustic protection of buildings, as well as in terms of safety. A very wide range of solutions are available for the various dimensional and functional requirements of each architectural project.
Below there is a glass glossary used in architecture.
Float glass is the transparent starting product, suitable for subsequent processing in various ways, in order to meet every safety standard, as well as ensuring thermal, mechanical and acoustic functionality.
This is a glass panel consisting of two or more glass sheets joined to each other over the entire surface by means of one or more high-strength PVB (Polyvinyl Butyral) plastic films. In this way, should the grass break, the shards will remain attached to the film, reducing the risk of injury (according to UNI standards).
Depending on the safety class selected, which determines the composition, number and thickness of sheets and quantity of PVB, laminated glass offers protection against accidents, burglary, theft, bullets and explosions.
Laminated glass, tempered and with the appropriate addition of high-strength PVB, is used in the construction of railings, for good mechanical resistance.
In areas with high noise levels, laminated glass, with the addition of a special type of PVB, also improves the acoustic performance of the glazing.
Low emissivity glass
This is the glass sheet for the building industry with one treated surface (normally with metal deposits and/or metal oxides), used to minimize heat loss due to temperature differences between the inside and the outside. This is possible because the glass "reflects" a high percentage of the heat radiated by the heating elements (radiators, radiant panels, electrical equipment, etc.) back towards the inside of the building. Therefore, while on the one hand it limits the escape of heat, on the other it promotes the penetration of light inside the building, ensuring energy and financial efficiency.
This is a sheet of float glass with one side treated with metal and/or metal oxide deposits. It features a selective reflection of the infrared radiation that limits the transmission of external heat but facilitates the passage of light, optimizing thermal insulation and the filtering of sunlight. It is therefore used for large windows or continuous glass walls.
The technology of this glass has now evolved to the point that it also integrates the performance features of low emissivity glass, ensuring optimized thermal performance levels whilst also promoting conditioning.
Double glazing (or insulating glass panel)
This is a glass panel consisting of at least two sheets of glass separated by a gap of dry air or gas (usually Argon) and an aluminium or high thermal insulation spacer (called Warm Edge). It is possible to obtain glass panels with different performance levels, depending on the type, thickness and treatment of the glass sheets and the thickness of the gap.
Tempered glass is heat-treated in a special furnace using a process called tempering, which aims at increasing the mechanical strength of the glass sheet. This glass is at least five times stronger than ordinary glass and features superior thermal shock resistance.
When broken, tempered glass fragments into a multitude of small pieces, therefore limiting the risk of injury. Tempered glass shows small deformations in reflection, which vary according to the thickness of the glass, distance and angle of observation. This is a normal phenomenon and inherent to the thermal production process.
Float, selective and low emissivity glass can be tempered while preserving the light, thermal and acoustic characteristics without changes.
Grinding is the processing of the edges of a sheet that allows contact with the same in full safety.
There are two types of grinding: raw edge (matt and rough edge) and polished edge (smooth and 45° bevelled edge). The edges are bevelled at 45° in both types.