Glazing Industry Terms

Our industry is very specialized and we use many terms and phrases that many people don’t understand. Below is a list of many of the technical names and terms with their definition as related to our industry. Click one of these links to skip to a section.

Aluminum:

6063-T5 alloy: T5 temper 6063 has an ultimate tensile strength of at least 20,000 psi (152 MPa) in thicknesses up to 0.5-inch (13 mm), and 19,000 psi (145 MPa) from 0.5 to 1.0-inch (25 mm) thick, and yield strength of at least 14,000 psi (110 MPa) up to 0.5-inch (13 mm) and 13,000 psi (103 MPa) (from 0.5 to 1.0-inch (25 mm). It has elongation of 8%
6061- T6 alloy: 6061 is a precipitation hardening aluminum alloy, containing magnesium and silicon as its major alloying elements. Originally called “Alloy 61S.” It has good mechanical properties and exhibits good weld-ability. It is one of the most common alloys of aluminum for general purpose use.
Extruded aluminum: Extrusion is a process used to create objects of a fixed cross-sectional profile. A material is pushed or drawn through a die of the desired cross-section. The two main advantages of this process over other manufacturing processes are its ability to create very complex cross-sections, because the material only encounters compressive and shear stresses. It also forms finished parts with an excellent surface finish.
Muntin member: A muntin is a strip of aluminum or metal separating and holding panes of glass in a window. Muntins are also called “muntin bars”, “glazing bars”, or “sash bars”. Muntins can be found in doors, windows, and glazed structures. Muntins divide a single window sash or casement into a grid system of small panes of glass, called “lights” or “lites”.
Poured and de-bridged: The thermal pour and de-bridge offers tremendous performance, protecting against temperatures of -100C (-148F). Extreme cold, nor hot temperatures, will transfer through an aluminum frame with pour and de-bridge thermal barrier. The pour and de-bridge method is suitable for withstanding the most demanding climates and conditions with the highest performance in impact resistance, sheer strength and heat distortion.
Pressure plate/cap: A piece of extrusion that holds a piece of glass or another piece of material in place by seamlessly locking into its opposite jointing member.
Purlin member: A Purlin is defined as a horizontal structural member in a roof. It supports the loads from the roof deck or sheathing and are supported by the principal rafters and the building walls, steel beams etc.
Rafter member: A rafter is one of a series of sloped structural members (beams) that extend from the ridge or hip to the wall plate, down slope perimeter or eave, and that are designed to support the roof deck and its associated loads. In recent buildings there is a preference for engineered trusses (trussed rafters) on the grounds of cost, economy of materials, off-site manufacture and ease of construction, as well as design considerations such as span limitation and roof load (weight from above).
Ridge member: A piece of aluminum or material that caps off the ridge or the upmost peak of a building or structure.
Sill member: The horizontal member that bears the upright portion of a frame, especially the horizontal member that forms the base of a window.
Thermal break: Frost and condensation aluminum face are significantly reduced with a thermal break. This is accomplished with a true thermally broken frame profile and delivers maximum protection against cold penetration.
Thermally broken: A separator material is used between the inner and outer frames to prevent the temperature transfer through the frame and condensation on the inside frame.
Weepage system/tracks: The secret to dealing with water penetration is providing a system that has a redundant drainage system incorporated as part of its design which can control the penetration. This drainage system will allow for the collection of any water infiltration and drainage back to the exterior. This type of drainage system is commonly referred to as a “weepage system.”

Energy Terms

Absorption: The percentage of light or radiation that is absorbed by a piece of glass or metal.
Annealed Glass: Not tempered may break fairly easily. Dangerous if broken.
Argon: An inert gas used as a high-performance insulator. Significantly reduces energy costs by controlling heat loss and heat gain. SSR uses argon between the lites of insulated glass units in SilverCoat ETM and SilverCoat Max E-Z CleanTM.
Clear Glass: Standard, non-high-performance glass that has little or no color (referred to as Crystal Shield ™ by SSR)
Conduction: Heat or cold transfer through a solid material such as aluminum or glass. The heat is transferred by the molecules that touch each other through the solid substance.
Convection: Heat or cold transfer through air molecules touching each other. Hot air rises because the heat-filled molecules are actively colliding against each other; thus, the air is less dense, which causes it to rise. As the air starts cooling, it becomes denser and heavier, which causes it to descend.
Daylight (Visible Light) Transmittance: The percentage of light or radiation passing through a piece of glass, metal, or other surfaces. Represented in most glass performance data as a percentage (the higher the percentage, the more light is allowed through the glass).
Dew Point: The temperature at which moisture in the air condenses and turns to water on a surface. The dew point based on a combination of the relative humidity (amount of moisture in the air) and the temperature of the surface.
Dual-Glazed (IG): Two lites of glass separated by an air space, and sealed to prevent moisture and condensation from clouding glass.
Heat Transfer: Heat always moves from hot to cold. It is mainly transferred by three methods of heat transfer: convection, conduction, and radiation.
Laminated Glass: Two pieces of glass (annealed or heat-strengthened) with a sheet of plastic laminated between. Often used in overhead glazing in commercial applications for safety (laminated glass will crack or spiderweb if broken but not shatter). Also significantly reduces UV transmission and noise.
Long Wave Radiation: Radiation from a heat source (for example from a hot stove, an asphalt parking lot, etc). This is also referred to as far infrared radiation or black box radiation.
Low-Emissivity (LoE) Coatings: Mineral or metallic coatings applied to glass which affects long and/or short wave radiation. They significantly reduce energy costs by helping to control the temperature within a glazed unit. Sunshine Rooms recommends SilverCoat ETM or SilverCoat Max E-Z CleanTM.
PAR (Photosynthetic Active Radiation): The percent of light that plants need to grow. Plants rely on full-spectrum light, not just on UV light. Glass types like Crystal Shield (clear temp), SilverCoat ETM, and SilverCoat Max E-Z CleanTM are appropriate for plant growth and propagation.
R Value: The resistance of heat loss due to the combination of conduction and convection. The higher the R-Value and better insulation, the higher the resistance. Represented in most glass performance data as a decimal (the lower the number, the better the performance).
Radiation: Energy that is transmitted from an energy source traveling through the electromagnetic field. Examples of electromagnetic radiation are x-rays, microwaves, radio waves, light waves, near infrared (heat producing waves), UV waves, etc.
Reflectance: The proportion of radiation or light that is reflected from surfaces such as glass or metal.
Relative Heat Gain: The amount of heat gained through glass considering both U-Value (the combination of convection and conduction) and shading coefficient (the measure of radiation) into a measure of BTU per hour per square foot. Relative heat gain = (summer – Value X 14 degrees difference between indoor and outdoor air temperatures) + (shading coefficient X 200 BTU/HR/sq. ft.. (*F). Represented in most glass performance data as a number (the lower the number, the better the performance).
Shading Coefficient: The percent of radiation that a piece of glass allows to pass through as compared to a 1/8″ piece of clear glass. The more radiation is allowed through, the higher the shading coefficient. Represented in most glass performance data as a decimal where a lower number represents better performance.
Short Wave Radiation: Radiation from a source such as the sun that has not yet turned into heat. This is also referred to as near infrared radiation.
Single-Glazed: A single lite of glass (not insulated).
Solar Cool Bronze: Bronze glass that has a pyrolytic (reflective metal) coating usually applied to surface 1 or 2 of the outboard lite.
Tempered Glass: Glass that has been heated and then cooled very quickly, making it up to ten times as strong as annealed glass. If broken, tempered glass will shatter into tiny harmless pellets.
Thermally Broken: Exterior metal does not come into contact with interior metal on a unit. They are separated by a polyurethane thermal break. All Sunshine Rooms products are 100% thermally-broken, including accessories like windows, roof vents, and doors.
Tinted Glass: Tint is mixed into glass during the liquid state causing the glass to be colored throughout. The darker glass reduced light and radiation mainly by absorption, but the dark glass heats in the process. Examples include Bronze and Solar Cool Bronze.
U Value: The acceleration of heat from outside to inside due to the combination of conduction and convection. The faster the acceleration, the higher the U Value (represented in most glass performance data as a decimal where low U Value = better performance).
UV/Ultraviolet:A spectrum of the sun’s rays. UV rays may cause fading and deterioration of fabrics and furnishings.

Engineering / Structural Terms

Live load: A moving, variable weight added to the dead load or intrinsic weight of a structure or vehicle.
Wind load: High winds can be very destructive. The speed of the wind–or wind velocity–acts as pressure when it meets with a structure. The intensity of that pressure is the wind load. There are many factors that can be considered in wind calculations for load and they are useful in designing and constructing wind-resistant buildings. Knowing how to calculate wind load can help people create safer buildings.
Exposure: The condition of being exposed to natural surrounding elements such as weather or other forces of nature.
Dead load: The still (without motion) intrinsic weight of a structure or vehicle.
Roof load: Loads that are produced during maintenance by workers, equipment, and materials, and during the life of the structure by movable objects which do not include wind, snow, seismic or dead loads.
Seismic loads: Seismic loading is one of the basic concepts of earthquake engineering which means application of an earthquake-generated agitation to a structure. It happens at contact surfaces of a structure either with the ground, or with adjacent structures, or with gravity waves from tsunami. Seismic loading depends, primarily, on anticipated earthquake’s parameters at the site – known as seismic hazard.
Deflection ratio: Deflection in roof extrusions isn’t a problem in most cases. But if you get long span trusses or those with a shallow depth you can run into problems. One instance would be a flat truss for a commercial roof. If you get too much deflection water ponding can be a problem. Another example would be a long span residential ribs. In this area 50′ trusses are common on duplexes. They can have a lot of deflection. Especially if the trusses have vaulted ceilings.

Glazing Terms

Acid etched glass: Abrasive sandblasting is also a common technique for creating patterns in glassware, creating a “frosted” look to the glass. High pressure air mixed with an abrasive material cuts away at the glass surface to create the effect. The longer the stream of air and abrasive material are focused in one spot, the deeper the cut will be. Sandblasting is often used for removing unwanted items that have stuck to the glass or as a decorative purpose on gifted and personal items.
Acrylic (monolithic): Is 10 to 20 times more impact resistant than glass and does not shatter like tempered glass. Instead, acrylic dents if the impact is strong enough. Acrylic glazing comes in many different colours and levels of clarity or opacity. Acrylic Glazing is a tough, transparent thermoplastic polymer of methyl methacrylate. It is used as a substitute for glass under the proprietary names of Perspex, Plexiglas and Lucite. Acrylic glazing provides an unsurpassed light transmission, matching that of glass and is half its weight. Inherently UV resistant, acrylic glazing is the ultimate choice in high traffic acoustic barriers. At 17 times more impact resistant, Acrylic Glazing makes an outstanding glazing material.
Acrylic (multi wall): Is a dual or triple layer that is 10 to 20 times more impact resistant than glass and does not shatter like tempered glass. Instead, acrylic dents if the impact is strong enough. Acrylic glazing comes in many different colours and levels of clarity or opacity. Acrylic Glazing is a tough, transparent thermoplastic polymer of methyl methacrylate. It is used as a substitute for glass under the proprietary names of Perspex, Plexiglas and Lucite. Acrylic glazing provides an unsurpassed light transmission, matching that of glass and is half its weight. Inherently UV resistant, acrylic glazing is the ultimate choice in high traffic acoustic barriers. At 17 times more impact resistant, Acrylic Glazing makes an outstanding glazing material.
Annealed glass: Not tempered; may break fairly easy. Dangerous if broken.
Ceramic frit glass: Silk-screening ceramic frit onto glass lets a designer create a subtle or bold look for a building-using patterns and color. Silk-screened glass improves solar control performance and can be combined with clear or tinted glass substrates, as well as with high-performance coatings to reduce glare and decrease solar transmission.
Desiccant: One example of desiccant usage would be in the manufacture of insulated windows where zeolite spheroids fill a rectangular spacer tube at the perimeter of the panes of glass. The desiccant helps to prevent the condensation of moisture between the panes. Another use of zeolites is in the dryer component of air conditioning systems to help maintain the efficacy of the refrigerant.
Fenestration: The arrangement and design of windows in a building.
Heat strengthen (HS) glass: Heat-strengthened glass is produced by heating the glass to approximately 1,300ºF and then rapidly cooling it with air. The resultant glass is thermally strengthened and approximately 2 times stronger than a piece of annealed glass. The increased strength is the result of permanently locking the outer surface molecules of the glass in compression and the center portion in a compensating tension.
Insulated glass: Insulated Glass Units are manufactured with glass in range of thickness from 3 mm to 10 mm (1/8″ to 3/8″) or more in special applications. Laminated or tempered glass may also be used as part of the construction. Most units are manufactured with the same thickness of glass used on both panes, but special applications such as acoustic attenuation or security may require wide ranges of thicknesses to be incorporated in the same unit.
Laminated glass: Two pieces of glass (Annealed or Heat-strengthened) with a sheet of plastic laminated between. Often used in overhead glazing in commercial applications for safety (laminated glass will crack or spiderweb if broken, but it will not shatter). Also it significantly reduces UV transmission and noise.
Low – e coatings (hard coat): With traditional hard-coat low-e, a low-emissivity layer of indium tin oxide is applied when the glass is still molten and just beginning to harden in the float-glass “lehr” where it is produced (see last week’s blog for a description of float-glass manufacturing). Denoting the high-temperature production, these coatings are also referred to as “pyrolytic” low-e. The indium tin oxide becomes part of the glass and, as a result, the low-e coatings becomes more durable. That’s why hard-coat low-e is the type of low-e preferred for storm windows where the coating has to withstand washing and other abrasive actions.
While hard-coat low-e is more durable than soft-coat, the emissivity isn’t as low, so these glazing’s don’t achieve as low a U-factor. On the other hand, they allow more sunlight to pass through, so they are usually better for houses that are relying on passive solar heating.
Low – e coatings (soft coat): The low-e coatings directly deposited onto the glass there are two broad categories: soft-coat and hard-coat. With soft-coat low-e, a thin layer of silver is deposited onto the glass through a sputtering process after the glass has been manufactured. While the earliest soft-coat low-e had a single layer of silver, coatings with two layers (low-e squared) and three layers (low-e cubed) came along since that have even lower emissivity and lower heat loss. These sputtered coatings have been referred to as “soft-coat” because the coatings remain fairly delicate and have to be protected within the insulated glass unit (facing the air space)–though that might be changing.
Polycarbonate (monolithic): Is one of the strongest clear-as-glass glazing material available today. It is typically 200 times stronger than glass yet weigh less than half which makes it an ideal material for roofing as well as around swimming pools. Its strength makes it an ideal glazing material for windows in high-traffic areas or areas subjected to potential impact (golf courses – ball parks – children’s playgrounds etc.)
Polycarbonate (multi wall): Is a dual or triple layer one of the strongest clear-as-glass glazing material available today. It is typically 200 times stronger than glass yet weigh less than half which makes it an ideal material for roofing as well as around swimming pools. Its strength makes it an ideal glazing material for windows in high-traffic areas or areas subjected to potential impact (golf courses – ball parks – children’s playgrounds etc.)
PVB film: Polyvinyl butyral (or PVB) is a resin usually used for applications that require strong binding, optical clarity, adhesion to many surfaces, toughness and flexibility.
Pyrolytic coatings: Pyrolytic glass, also known as hard coated or online coated glass, is made through a one-step process and is produced at the same time as the base glass. In the process, the chemical coating that gives the finished glass its properties is bonded to the glass while it is in a semi-molten state. Therefore, the chemical composition becomes part of the glass surface, rather than a layer on top of the surface, making the glass more durable. Pyrolytic low-E can be handled and processed like standard float glass resulting in excellent lead time, customer service and overall cost effectiveness with use of the product.
Simulated divided lites: Aesthetic cross member grids made of aluminum that give the glass or glazing a classy old-world look. They also help insulate the window panes with and over sized internal and external grid.
Solar Cool glass: Solar cool reflective coated glass provides maximum flexibility due to the durability of the metallic oxide coating that is deposited onto the float glass during production. Solar cool glass can be glazed with the reflective coating positioned on either the first or second surface. The glass has improved performance and higher exterior visible reflectivity when installed with the coating on the first surface. When installed with the coating on the second surface, the glass has lower exterior visible reflectivity and maintains the substrate glass color.
Spacer bar: Tempered bendable aluminum tubing which separates the panes of glass in a dual or triple pane panel of insulated glass.
Spacer grids: Aesthetic cross member grids made of aluminum that give the glass or glazing a classy old-world look. They also help insulate the window panes (Built inside the glass).
Tempered glass: Glass that has been heated then cooled very quickly, making it up to ten times as strong as annealed glass. If broken tempered glass will shatter into tiny harmless pellets.
Tinted glass: Tint is mixed into the glass during the liquid state causing the glass to be colored throughout. The darker glass reduced light and radiation mainly by absorption, but the dark glass heats in the process. Examples include bronze and solar cool bronze.

Hardware Terms

Closed cell tape: High-tack, pressure-sensitive acrylic adhesive on one side of a strip of urethane or vinyl foam bonds the foam to most surfaces. For gasketing, sealing, baffling, cushioning and insulation. Varying thicknesses of high – or low-density high – or medium-density closed cell vinyl.
Dual sided tape: Adhesive on both sides of a strip of urethane or vinyl tape bonds the tape to most surfaces.
EDPM rubber: EPDM rubber is used in seals (for example it is used in cold-room doors since it’s an insulator, as well as in the face seals of industrial respirators in automotive paint spray environments, where silicone must be avoided).
Glazing tape: Structural Glazing Tape is a two-sided pressure sensitive acrylic foam tape designed to bond glass to metal frames in glass curtain wall systems. These tapes are specifically designed to withstand the stresses and performance requirements faced in 4-sided unitized shop glazed curtainwall.
Open cell tape: A type of weatherstrip foam tape. It is designed to compress easily and is almost mistake proof as the tape easily compresses to fill any gap that it is used on and comes in a variety of densities. Keeps bugs and dust out while still allowing air and moisture in.
PVC gaskets: Polyvinylchloride (PVC) Foam Gaskets: PVC gaskets are soft and pliable. They are ideally suited for applications involving moisture. They conform well to irregular surfaces and are available with pressure sensitive adhesives. PVC gaskets offer low compression set and improved temperature stability for continuous temperatures over 230 degrees F.
Santoprene rubber: It is supplied as pre-compound material that can be processed using conventional thermoplastic tools. The difference is that Santoprene elastomer possesses the same levels of flexibility and durability that are commonly found with natural rubber compounds. Because of the longer life of Santoprene elastomer in both extreme hot and cold environments, the material is often preferred over the use of rubber.
Single sided tape: Adhesive on one side of a strip of urethane or vinyl tape bonds the tape to most surfaces.
VHB tape: Since 1980, (3M Very High Bond tape) VHB, a high-strength double-sided adhesive tape VHB Tape has offered unlimited design and application possibilities for designers. By working with 3M’s engineering experts, product designers know they can count on this reliable solution. Lab-tested and proven in the real world, 3M™ VHB™ Tape eliminates rivets, bolts, screws and welds.

Aluminum:

Energy Terms

Engineering / Structural Terms

Glazing Terms

Hardware Terms

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