Complete technical dictionary of the glass, window and enclosure sector. Each term includes its detailed definition, context of use and relationship with other concepts. Organized alphabetically for easy consultation.

A

Glazing

Set of glass and elements that make up the transparent part of a window, door or enclosure. It can be simple (un solo vidrio), doble (dos vidrios con cámara de aire o gas) o triple (three panes of glass with two chambers). The type of glazing determines the thermal and acoustic insulation of the carpentry.

Aireador

Device integrated in the window profile that allows controlled ventilation without the need to open the leaf. Complies with CTE DB-HS3 on indoor air quality. It can be adjustable or self-regulating depending on the wind pressure.

Anclaje

Fixing system that joins the frame of the window or enclosure to the work (wall, floor). There are mechanical (screws, plugs), chemical (epoxy resins) and mixed anchors. The choice depends on the material of the support and the loads that the element must bear.

Argón (Gas)

Inert noble gas used as a filling in insulating glass chambers (double or triple glazing). Reduces thermal conductivity compared to dry air by 34%, improving the Ug value of the glazing. Its density (1.78 kg/m³) is higher than that of air, which reduces internal convective currents.

Arenado

Process of surface treatment of the glass that consists of projecting abrasive particles (silica sand, corundum) under pressure on the surface. Produces a matte translucent finish that diffuses light and provides privacy. It can be applied uniformly or selectively (using templates) to create decorative designs. Unlike acid, sanding has a rougher texture to the touch.

B

Low-E (Low-E)

Surface treatment of glass by depositing microscopic metallic layers (usually silver oxides) that reduce the emissivity of the glass surface. This allows the glass to reflect long-wave infrared radiation (radiant heat) inwards in winter, improving thermal insulation. Emissivity values range from 0.89 (normal glass) to 0.01 (high performance). It is measured with the Ug value of the assembly.

Biselado

Machining process that consists of carving an oblique angle on the edge of the glass, creating an inclined edge that reflects light in a decorative way. It is done with diamond wheels on bevelling machines. The bevel can be of different widths (10-50 mm) and angles. It is a typical finish in decorative mirrors, glass tables and passage doors.

Block (Calzo)

Piece of plastic material (polypropylene, nylon, EPDM) that is placed between the glass and the carpentry profile to position, level and transmit the weight of the glass to the frame. There are three types: calzos de apoyo (soportan el peso), calzos laterales (centran el vidrio) y calzos de acuñado (prevent displacement). Its correct placement is essential to avoid stress and breakage.

Butilo

Primary sealant used in the manufacture of insulating glass (double glazing). It is applied hot on the spacer profile, forming a hermetic barrier against moisture penetration and gas leakage. It is the first seal of the double sealing system that guarantees the durability of the insulating glass unit.

C

Calzo

Ver Block.

Cámara (de aire/gas)

Hermetic space between two glasses in an insulating glazing. It can be filled with dehydrated air or noble gases (argon, krypton). The optimal thickness of the chamber for thermal insulation is 16 mm; for acoustic insulation, asymmetrical chambers are recommended (for example, 12+16). Chambers larger than 20 mm do not significantly improve insulation and can generate convective currents.

Canteado

It is the process of machining the edges (borders) of the glass to eliminate the sharp cutting edges that remain after cutting. It is done with diamond abrasive wheels. Main types: canteado mate (C-grind, elimina el filo sin pulir), canteado brillante (pulido a espejo) y canteado plano (polished straight edge). It is mandatory in tempered glass (must be done before tempering) and in any glass accessible to the user.

Cargadero (Dintel)

Horizontal structural element located above the window opening that supports the loads of the upper wall and transfers them to the jambs. It can be made of reinforced concrete, steel or stone. It determines the maximum width of the opening and conditions the type of anchoring of the subframe.

Cerramiento

Construction system that closes a space by means of glass and profiles, creating an environment protected from the weather but with high transparency. It differs from the window in that it covers larger surfaces and, in many cases, lacks operable leaves or has only a few. Includes glass curtains, glazed roofs and lightweight facades.

Climalit®

Registered trademark of Saint-Gobain for its insulating glass units (double glazing). Although it is a commercial brand, it has become a generic term to refer to any glass with a chamber. A standard Climalit consists of two float glasses separated by an intercalary profile with desiccant, hermetically sealed. The nomenclature indicates composition: 4/16/4 = 4 mm glass + 16 mm chamber + 4 mm glass.

CNC (Control Numérico)

Automated machining system used in glass processing to perform drilling, milling, shape cutting and edging with millimeter precision. CNC machines for glass work with diamond tools and water cooling. They allow producing complex parts with tolerances of ±0.5 mm.

Coeficiente K (obsoleto) / Valor U

Antiguo término para el coeficiente de transmitancia térmica, ahora denominado valor U. Measures the amount of heat that passes through an element per unit area and temperature difference (W/m²·K). The lower the value, the better the insulation. For windows: Uw (ventana completa), Uf (marco), Ug (vidrio). El CTE DB-HE establece valores máximos según zona climática.

Solar control

Property of certain glasses treated with metallic layers that reduce the entry of solar radiation (especially infrared) into the interior. It is measured by the factor solar (g): percentage of total solar energy that passes through the glass. A solar control glass can have a g-factor of 0.25-0.45 compared to 0.85 for a normal float glass. It must be balanced with light transmission to maintain clarity.

Glass curtain

Frameless enclosure system with no visible vertical profiles, formed by tempered glass leaves that slide and stack laterally. Each leaf is suspended from an upper rail by means of bearings and can rotate on its axis to fold completely. It has no thermal break or total tightness: it is a semi-open enclosure. Usual thicknesses: 8 or 10 mm.

D

Desecante (Tamiz molecular)

Hygroscopic material (zeolite) contained within the spacer profile of the insulating glass. Its function is to absorb the residual moisture trapped in the chamber during manufacturing, preventing internal condensation between the glass panes. Desiccant saturation is the main cause of "fogging" in old glazing.

Doble acristalamiento

Insulating glass unit composed of two panes of glass separated by a chamber of air or inert gas, hermetically sealed. Significantly improves thermal insulation (Ug from 2.7 to 1.0 W/m²·K depending on composition) and acoustic insulation compared to single glass. The standard nomenclature indicates: outer glass thickness / chamber / inner glass thickness (e.g. 6/16/4).

E

Emisividad

Capacity of a surface to emit radiant energy. In glass, the normal emissivity of float glass is 0.89 (it emits 89% of the infrared radiation it receives). Low-emissivity glasses reduce this value to 0.01-0.10 by means of metallic layers, which drastically improves thermal insulation by reflecting heat back into the interior.

EPDM

Synthetic rubber (Ethylene-Propylene-Diene) used as a sealing gasket in windows and enclosures. It resists weathering, UV rays, ozone and extreme temperatures (-40°C to +120°C). It is used in glazing gaskets, sealing gaskets between the leaf and frame, and as a perimeter compression band.

Esmalte cerámico (Serigrafía)

Glass decoration process that consists of applying colored enamels (ceramic frits) by screen printing and then melting the enamel during the tempering process. The result is a permanent color integrated into the surface mass of the glass, resistant to scratching, weathering and cleaning products. Applications: facade glass (spandrel), decorative screens, signage.

Extraclaro

Float glass manufactured with raw materials with a low iron oxide content, which eliminates the greenish tint typical of standard glass. Light transmission of 91% compared to 82% for normal float. It is essential for applications where colour fidelity is required (displays, furniture) or maximum light transmission (solar panels, lighting).

F

Solar factor (g)

Coefficient that indicates the proportion of total solar energy that passes through a glazing, including direct transmission and re-emission by heating of the glass. It is expressed in decimal value (0 to 1) or percentage. A g-factor = 0.30 means that only 30% of the solar energy penetrates the interior. The CTE DB-HE limits the solar factor according to orientation and climatic zone to control the cooling demand.

Float

Manufacturing process of flat glass invented by Pilkington in 1959. The molten glass is poured onto a bath of liquid tin, where it floats and spreads, forming a perfectly flat sheet of uniform thickness. 90% of the world's flat glass is manufactured by this method. Standard thicknesses: 2, 3, 4, 5, 6, 8, 10, 12, 15 and 19 mm.

Fresado

Glass machining operation that consists of reducing material from the surface or edge by means of rotating diamond milling cutters. It is used to create lock recesses in glass doors, notches for hinges, indentations and complex shapes. It is usually performed on CNC machines with water cooling.

G

Galce

Rebate or groove in the carpentry profile where the glass is housed. The glazing rebate must have the appropriate dimensions for the thickness of the glazing plus the weatherstripping. In PVC profiles, the glazing rebate is usually 20-28 mm for double glazing. An insufficient glazing rebate prevents the installation of high-performance glazing.

Gas noble

Inert gases (argon, krypton, xenon) used as filling of the chamber in insulating glass to improve thermal insulation. The argón es el más habitual (mejora un 34% respecto al aire), el kriptón offers a 50% improvement but is more expensive. They are injected during the manufacturing process of the insulating glass before final sealing.

H

Heat Soak Test (HST)

Thermal resistance test that subjects the tempered glass to a controlled heating cycle (290°C for hours) to cause the breakage of glasses with nickel sulphide (NiS) inclusions. These inclusions can cause spontaneous breakage months or years after tempering. The HST eliminates approximately 95% of defective glasses, being mandatory in high safety applications (facades, roofs, railings without uprights).

Hardware

Set of metal parts that allow the operation of a window: hinges, stays, espagnolettes, handles, strikers and opening limiters. The quality of the hardware determines the durability and comfort of use of the window. The reference brands are Roto, Siegenia and Winkhaus. Tilt and turn hardware is the most complex.

Sheet

Movable part of the window that contains the glazing and is articulated or slides with respect to the fixed frame. According to the type of opening: operable leaf (vertical rotation), tilt-and-turn leaf (vertical rotation + upper folding), sliding leaf (horizontal sliding), tilting leaf (horizontal rotation). The weight of the leaf depends on the glazing and the material of the profile.

I

Intercalario (Perfil separador)

Profile that separates the glass in an insulating glazing, defines the width of the chamber and contains the desiccant. It can be made of aluminum (económico, pero puente térmico), acero inoxidable o plástico/composite (warm edge, improves perimeter insulation). The choice of the spacer significantly influences the final Uw value of the window and the perimeter condensation.

J

Jamba

Each of the two vertical elements of the window opening in the wall. Together with the lintel (upper) and the sill (lower), they form the opening where the carpentry is installed. The jambs must be plumb and capable of supporting the anchors of the subframe or direct frame.

Junta de estanqueidad

Flexible profile (EPDM, TPE, silicone) that guarantees the tightness between the different components of the window: between glass and profile (glazing gasket), between sash and frame (closing gasket), and between frame and construction (perimeter gasket). High-quality windows incorporate 2 or 3 closing gaskets (outer, central and inner gasket) for maximum tightness.

L

Lacquered

Surface treatment of aluminum profiles consisting of applying powder paint (polyester) by electrostatic charging and curing in an oven at 180-200°C. The result is a durable and weather-resistant finish available in any RAL color. The lacquering must comply with the Qualicoat standard to guarantee its durability (minimum 60 microns thick). Alternative to anodizing, allows custom colors.

Laminated

It is the process of manufacturing safety glass that consists of joining two or more sheets of glass by means of one or more interlayers of PVB (polyvinyl butyral), EVA or SGP, by heat and pressure in an autoclave. Laminated glass, in case of breakage, keeps the fragments adhered to the interlayer, preventing the fall of cutting pieces. It is mandatory in railings, skylights, screens and any glass at height. The nomenclature indicates: 44.2 = two 4 mm glasses with 2 PVB sheets (0.76 mm).

M

Mateado al ácido

Chemical treatment of the glass that consists of submerging the piece in a solution of hydrofluoric acid, creating a uniform satin finish and soft to the touch. Unlike sanding, acid etching produces a finer surface, easy to clean and resistant to fingerprints. It is used in bathroom screens, office partitions and high-end decorative elements.

Monolithic

Glass formed by a single sheet, without chamber or lamination. It is glass in its most basic form (float cut to size). It can be tempered or annealed. It is distinguished from insulating glass (with chamber) and laminated glass (several sheets joined with PVB). Uses: simple glazing, shelves, mirrors, decorative stained glass.

Montante

Intermediate vertical profile that divides a large opening into smaller spans. In carpentry, the mullion (also called a «parteluz») allows solving wide openings while maintaining structural rigidity. In glass railings, the mullion is the vertical post that holds the glass panels.

O

Tilt and turn

Sistema de apertura de ventana que combina dos movimientos con una sola manilla: batiente (giro sobre eje vertical lateral, apertura completa) y oscilo (rotation on lower horizontal axis, limited upper opening for ventilation). It is the most versatile system and the standard in high-end PVC and aluminum carpentry. Requires complete perimeter hardware.

P

Premarco

Auxiliary structure (usually made of aluminum, galvanized steel or PVC) that is fixed to the opening of the work before the placement of the window. It allows the bricklayer to leave the opening prepared during the construction phase and the carpenter to install the window later in a clean and precise way. Facilitates the future replacement of the window without works. Also called «pre-frame» or «counter-frame».

Puente térmico

Area of a building's envelope where there is a greater transmission of heat due to a change in material, thickness or geometry. In windows, the greatest thermal bridge occurs in the metal frame. The rotura de puente térmico (RPT) on aluminum profiles consists of interposing a polyamide bar between the inner and outer face of the profile, drastically reducing thermal transmission.

PVB (Butiral de polivinilo)

Transparent plastic sheet used as an interlayer in laminated safety glass. It is flexible, transparent and has great adhesion to glass. Standard thickness: 0.38 mm per layer (2, 3 or 4 layers are stacked according to requirements). Special variants: acoustic PVB (greater sound insulation), coloured PVB (decorative) and structural PVB (SGP, greater rigidity).

R

RPT (Rotura de Puente Térmico)

Technology applied to aluminum profiles that consists of inserting glass fiber reinforced polyamide bars between the outer and inner face of the profile, interrupting the metallic continuity. This reduces the thermal transmittance of the frame (Uf) from ~5.7 W/m²·K (without TPS) to 1.5-2.5 W/m²·K (with TPS). It is a CTE requirement for most climatic zones in Spain.

Rw (Índice de reducción acústica)

Magnitude that expresses the capacity of an element (glass, window) to reduce noise, measured in decibels (dB) according to standard UNE-EN ISO 717-1. Indicative values for glass: float 4 mm ≈ 30 dB, laminated 44.2 ≈ 36 dB, asymmetrical double glazing ≈ 38-45 dB. The CTE DB-HR establishes minimum values according to the situation and use of the building.

S

Selectividad

Relationship between light transmission (TL) and solar factor (g) of a glass: S = TL / g. A selective glass lets a lot of light through but little heat. Selectivity values above 1.5 are considered good; above 2 are excellent. The latest generation of glass achieves selectivities of 2.0-2.3, making them ideal for south and west facing facades.

Serigrafía

Ver Esmalte cerámico.

SGP (SentryGlas® Plus)

Ionoplast interlayer manufactured by Kuraray (formerly DuPont) with 5 times greater rigidity and strength than standard PVB. Laminated glass with SGP maintains its load-bearing capacity even with both panes broken (post-breakage). It is the standard for structural glass railings, glass floors and applications where maximum safety is required.

Silicona estructural

High mechanical strength silicone adhesive/sealant used to fix glass to supporting structures in lightweight facades (structural silicone glazing or SSG curtain wall). It withstands wind loads, self-weight and thermal movements. Requires specific structural calculation and application by qualified personnel. Do not confuse with conventional sealing silicone.

T

Taladro

Circular perforation made in the glass by means of diamond tubular drill bits with water cooling. The holes allow to fix fittings (hinges, handles, screws) in doors, screens and railings. Usual diameters: 8-50 mm. In tempered glass, ALL holes must be made BEFORE the tempering process, since the tempered glass cannot be machined later without breaking.

Tempering

It is the process of thermal treatment of glass that consists of heating the glass to ~620°C and rapidly cooling it with jets of pressurized air. This generates compressive stresses on the surface and tensile stresses inside, increasing the mechanical resistance 4-5 times compared to annealed glass. In case of breakage, it fragments into small non-cutting pieces (safe fragmentation). It is mandatory in shower screens, glass doors and low-height enclosures. It cannot be cut or machined after tempering.

Transmitancia térmica (Valor U)

Ver Coeficiente K / Valor U.

Triple glazing

Insulating glass unit formed by three panes of glass separated by two gas chambers. It offers maximum thermal insulation (Ug up to 0.5 W/m²·K with noble gases and low-emissivity coatings). It is common in Northern Europe and cold climate zones. Its greater weight (≈30 kg/m² in standard composition) requires reinforced hardware and profiles with a wide rebate.

V

Valor U

Ver Coeficiente K / Valor U.

Vierteaguas

Inclined piece placed on the lower exterior part of the window opening, designed to evacuate rainwater to the outside, preventing it from penetrating the facade. It can be made of aluminium, stone, ceramic or folded sheet metal. It must have a minimum slope of 10% and a drip (lower lip) that prevents water from returning by capillarity to the wall.

Vidrio armado

Glass that incorporates a metal mesh inside, inserted during the manufacturing process. In case of breakage, the mesh retains the fragments. It was the first safety glass used historically, but it has been widely replaced by laminated glass, which offers better performance. It is still used in industrial skylights and as fire-resistant glass in E (integrity) classifications.

Vidrio con cámara

Ver Doble acristalamiento.

W

Warm Edge (Borde cálido)

Insulating glass spacer profile technology that uses materials with low thermal conductivity (plastics, composites, stainless steel) instead of conventional aluminum. Reduces the perimeter thermal bridge of the glazing, improves the Uw value between 0.1-0.3 W/m²·K and reduces the risk of condensation on the edge of the glass. Brands: Swisspacer, TGI, Chromatech.