Insulating glass (IG), which is more commonly known as double glazing (or double-pane, and increased triple glazing / pane), consists of two or three glass panes separated by a vacuum or gas filled space. the building envelope. Insulating glass units (IGUs) are manufactured with glass in thickness from 3 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 produced with the same thickness of glass as they require.

Insulating glass is an evolution of older technologies known as double-hung windows and storm windows. Traditional double-hung windows used in the kitchen. However, current reproductions of these old-style storm windows can be made with detachable glass in the background that can be replaced with a detachable screen when desired. This eliminates the need for changing the entire storm according to the seasons. Insulated glazing forms a very compact multi-layer sandwich of glass and air, which eliminates the need for storm windows. Screens can also be installed, and they can be installed in a window, and they can be installed in a window. It is possible to retrofit insulated glazing into traditional double-hung frames, though this would require significant modification to the wood frame due to the increased thickness of the IG assembly. Modern window units with IG typically completely replace the older double-hung unit, and include other improvements air leakage, provides protection against the sun and will keep the house cool and warm in winter. These spring-operated balancing facilities also typically permit the inward swing,

The glass panes are separated by a “spacer”. A spacer, also known as a warm edge, is the piece that separates the two panes of glass in an insulating glass system, and seals the gas space between them. Historically, spacers were made primarily of metal and fiber, which However, metal spacers conduct heat (unless the metal is thermally improved), undermining the ability of the insulated glass unit (IGU) to reduce heat flow. It may also result in water or ice forming at the bottom of the air gap. To reduce the heat transfer rate and the cost of the product, the manufacturers may make the spacer out of a less-conductive material such as structural foam.

IGUs are often manufactured on a standard basis on factory production lines, but standard units are also available. The width and height dimensions, the thickness of the glass panes and the type of glass for each and every one of them. On the assembly line, spacers of specific thicknesses are cut and assembled in the size and desiccant dimensions. We have a parallel line, glass panes are cut to size and washed to be optically clear. An adhesive sealant (polyisobutylene) is applied to the spacer of the spacer. If the unit is gas filled, two holes are drilled into the spacer of the assembled unit, lines are attached to draw the air out of the space and replace it (or just vacuum) with the desired gas. The lines are then removed and sealed to contain the gas. The most modern technique is online, which eliminates the need to drill holes in the spacer. The polysulfide or silicone sealant or similar material is used to prevent moisture from entering the unit. The desiccant will remove traces of humidity from the air. Some manufacturers have developed specific processes that combine the spacer and desiccant into a single step application system. The insulating glazing unit, One of the two panes of glass was found in the United States by Thomas Stetson in 1865. It was developed into a commercial product in the 1930s, when several patents were filed, and a product was announced by the Libbey-Owens-Ford Glass Company in 1944. The thermopane technology differs significantly from the contemporary IGUs. The two panes of glass were welded together by a glass seal, and the two panes were separated by the typical of modern units. The brand name Thermopane has entered the vocabulary of the glazing industry and the genericized trademark for any IGU. was patented in the United States by Thomas Stetson in 1865. It was developed into a commercial product in the 1930s, when several patents were filed, and a product was announced by the Libbey-Owens-Ford Glass Company in 1944. Their product was sold under the Thermopane brand name, which had been registered as a trademark in 1941. The Thermopane technology differs significantly from contemporary IGUs. The two panes of glass were welded together by a glass seal, and the two panes were separated by the typical of modern units. The brand name Thermopane has entered the vocabulary of the glazing industry and the genericized trademark for any IGU. was patented in the United States by Thomas Stetson in 1865. It was developed into a commercial product in the 1930s, when several patents were filed, and a product was announced by the Libbey-Owens-Ford Glass Company in 1944. Their product was sold under the Thermopane brand name, which had been registered as a trademark in 1941. The Thermopane technology differs significantly from contemporary IGUs. The two panes of glass were welded together by a glass seal, and the two panes were separated by the typical of modern units. The brand name Thermopane has entered the vocabulary of the glazing industry and the genericized trademark for any IGU. Their product was sold under the Thermopane brand name, which had been registered as a trademark in 1941. The Thermopane technology differs significantly from contemporary IGUs. The two panes of glass were welded together by a glass seal, and the two panes were separated by the typical of modern units. The brand name Thermopane has entered the vocabulary of the glazing industry and the genericized trademark for any IGU. Their product was sold under the Thermopane brand name, which had been registered as a trademark in 1941. The Thermopane technology differs significantly from contemporary IGUs. The two panes of glass were welded together by a glass seal, and the two panes were separated by the typical of modern units. The brand name Thermopane has entered the vocabulary of the glazing industry and the genericized trademark for any IGU.

The maximum insulating efficiency of a standard IGU is determined by the thickness of the space. Typically, most units achieve maximum insulating values ​​when measured at the center of the IGU. IGU thickness is a compromise between maximizing insulating value and the ability of the framing system used to carry the unit. Some residential and most commercial glazing systems can accommodate the ideal thickness of a double-paned unit. Issues arise with the use of triple glazing IGU. The combination of thickness and weight is more likely to be important for most residential or commercial glazing systems, particularly if these panes are contained in moving frames or sashes. This trade-off does not apply to vacuum insulated glass (VIG), or evacuated glazing, Condensed heat dissipation is caused by the loss of heat and the loss of heat. These VIG units have most of the air removed from the space between the panes, leaving a nearly-complete vacuum. VIG units which are currently in the process of being sealed with glass, which is a glass fried (powdered glass) having a reduced melting point is heated to join the components. This creates a glass seal that increases the temperature of the room. This stress can limit the maximum allowable temperature differential. One manufacturer provides a recommendation of 35 ° C. Closely spaced pillars are required to reinforce the glazing to resist the pressure of the atmosphere. Pillar spacing and diameter limited the insulation achieved by designs available beginning in the 1990’s to R = 4.7 h · ° F · ft2 / BTU (0.83 m2 · K / W) no better than high quality double glazed insulated glass units. R = 14 h · ° F · ft2 / BTU (2.5 m2 · K / W) where the triple glazed insulated glass units. The required internal pillars exclude applications where an unobstructed view through the glazing unit is desired, ie most residential and commercial windows, and refrigerated food display cases. Vacuum technology is also used in some non-transparent insulation products called vacuum insulated panels. An older-established way to improve insulation performance is to replace air in the space with a lower thermal conductivity gas. Convective heat transfer is a function of viscosity and specific heat. Monatomic gases such as argon, krypton, and xenon are often used at a higher temperature than at a higher temperature than poly-atomic gases. Argon has a thermal conductivity 67% that of air, krypton has about the conductivity of argon. Argon is almost 1% of the atmosphere at a moderate cost. Krypton and xenon are only trace elements of the atmosphere and very expensive. All of these “noble” gases are non-toxic, clear, odorless, chemically inert, and commercially available because of their widespread application in industry. Some manufacturers also offer sulfur hexafluoride as an insulating gas, especially to insulate sound. It has a stable, inexpensive and dense stability of argon. HOWEVER, sulfur hexafluoride is an extremely potent greenhouse gas that contributes to global warming. In Europe, under the F-Gas Directive, which uses several applications. Since January 1, 2006, it is not possible to trace gas and all applications except high-voltage switchgear. In general, the most effective is the optimum thickness, the thinner the optimum thickness is. For example, the optimum thickness for argon, and lower for argon than for air. However, since it is difficult to determine whether or not it has been used in the past, many designers prefer to use a thicker gap. were pure. Argon is commonly used in insulated glazing and is the most affordable. Krypton, which is more expensive, is not used to produce very thin double glazing units or extremely high performance triple-glazed units. Xenon has found very little application in IGUs because of cost.

The effectiveness of insulated glass can be expressed as an R-value. The higher the R-value, the greater is its resistance to heat transfer. A standard IGU consisting of clear uncoated panes of glass (or lights) with air in the cavity between the lights typically has an R-value of 0.35 K · m 2 /W.Using US customary units, a rule of thumb in standard IGU construction is that each change in the component of the IGU results in an increase of 1 R-value to the efficiency of the unit. Adding argon gas increases the efficiency to about R-3. Using low emissivity glass on surface # 2 will add another R-value. Properly designed triple-glazed IGUs with low emissivity coatings on surfaces # 2 and # 4 and filled with argon gas in the cavities result in IG units with R-values ​​as high as R-5. Certain vacuum-insulated glass units (VIGU) or multi-chambered IG units using coated plastics results in R-12.5 While the standard double glazing is most widely used, it is not uncommon, and quadruple glazing is produced for very cold environments such as Alaska. Even quintuple glazing is available – with mid-pane insulation factors equivalent to walls.

In some situations the insulation is in reference to noise mitigation. In these circumstances a large air space improves the noise insulation quality or sound transmission class. Asymmetric double glazing, using different thicknesses of glass rather than the conventional symmetrical systems (equal glass thicknesses used for both lights) will improve the acoustic attenuation properties of the IGU. If standard air spaces are used, sulfur hexafluoride can be used to replace or increase inert gas and improve acoustical attenuation performance. Other glazing material variations affect acoustics. The most widely used glazing configurations for sound dampening. Including a structural, thermally improved aluminum barrier against air in the insulating glass can improve acoustical performance by reducing the transmission of noise sources in the fenestration system. Review of the glazing system components, including the air space material used in the insulating glass.

The life of an IGU varies according to the quality of the materials used, temperature differences, workmanship and location of installation and management of the location. IG units typically last from 10 to 25 years, with windows facing the equator often lasting less than 12 years. IGUs typically carry a warranty for 10 to 20 years depending on the manufacturer. If IGUs are altered (such as installation of a solar control film) the warranty may be voided by the manufacturer. The Insulating Glass Manufacturers Alliance (IGMA) undertakes an extensive study to characterize the failures of commercial insulating glass units over a 25-year period. For a standard IG building unit, condensation collects between the layers of the glass when the perimeter seal has failed and the desiccant has become saturated, and can only be eliminated by replacing the IGU. Seal failure and subsequent replacement results in a significant factor in the overall cost of owning IGUs. Large temperature differences between the inner and outer panes stress the spacer adhesives, which can eventually fail. Units with a small gap between the panes are more prone to failure because of the increased stress. Atmospheric pressure changes combined with wet weather can, in rare cases, eventually leading to the gap filling with water. The flexible sealing surfaces preventing infiltration around the window can also degrade or be torn or damaged. Replacement of these seals can be difficult to impossible, to to to IG IG IG IG IG IG…….. Instead, the edge is installed by pushing an arrow-shaped indented one-way flexible lip into a slot on the extruded channel, and often can not be removed from the extruded slot to be replaced. In Canada, since the beginning of 1990, there are some companies offering servicing of failed IG units. In the glass and / or spacer. This solution often has visible condensation, but does not have the same effect on the surface of the glass and has not been exposed to moisture. They can offer a warranty from 5 to 20 years. This solution lowers the insulating value of the window, but it can be a “green” solution when the window is still in good condition. If the IG unit has a gas fill (eg argon or krypton or a mixture) the gas is naturally dissipated and the R-value suffers. Since 2004, there are also some companies offering the same restoration process for failed dual-glazed units in the UK, and there is a company offering restoration of failed IG units in Ireland since 2010.

Thermal stress cracking is not different for insulated glazing and uninsulated glazing. Temperature differences across the surface of glass panes can lead to cracking of the glass. This is where the glass is partially shaded and one section is heated in sunlight. Tinted glass increases heating and thermal stress, while annealing resists thermal stressing. Thermal expansion creates internal pressure, or stress, when expanding warm material is retrained by cooler material. A crack may form the stress of the material strength and the crack will be propagated to the point of stress. Typically cracks and propagates from the narrow shaded cut edge where the material is weak and the stress is spread over a small glass volume compared to the open area. Glass thickness has no direct effect on thermal cracking in both thermal stress and material strength are proportional to thickness. While thicker glass will have greater weight, it is usually only a significant factor for large glazing units on tall buildings and wind improves heat dissipation. Increased resistance to cracking with thicker glazing in residential and commercial applications. Cut edge stresses have been reduced by stress and stress. The cost to process is much greater than the cost difference between 1/8 “(3mm) glass and 3/16” (5mm) or 1/4 “(6.5mm) material, prompting glaziers to replace cracked glazing with thicker It should also be noted that the glass should have been used initially. 5mm) material, prompting glaziers to replace glazed glass with thicker glass. It may also be revealed to the customer that they should have been used initially. 5mm) material, prompting glaziers to replace glazed glass with thicker glass. It may also be revealed to the customer that they should have been used initially.

Given the thermal properties of the sash, the frame, and the dimensions of the glazing and thermal properties of the glass, the heat transfer rate for a given window and set of conditions can be calculated. This kilowatt hour can be calculated as kilowatt hours, based on kWh (kilowatt hours per annum). The glass panels in double-glazed windows by convection, by conduction through the frame, and by the penetration around the perimeter seals and the farme’s seal building. The actual rates will vary with the conditions throughout the year, and while solar gain can be much warmed up in the winter (depending on local climate), it can be achieved in summer. Unwanted heat transfer can be used in the summer. In this case, it has been suggested that the Window Energy Rating is WER, ranging from A for the best down to B and C etc. This is a combination of the heat loss through the window (U value, the reciprocal of R-value), the solar gain (g value), and loss through air leakage around the frame (L value). For example, A year in the future will be a typical year gain as much heat as it does in other ways (however the majority of this gain will occur during the summer months, when the heat may not be needed by the occupying building). This provides better thermal performance than a typical wall.