Solar & Thermal Control Glasses in Burj Khalifa

Burj Khalifa, renowned as the world’s tallest building, unveiled itself this New Year. At a height of 800 meters or 2,650 feet, this marvel in architecture truly reaches for the stars. The generous use of glass used in its construction gives it a dazzling appearance and several functional advantages. The glass for the Burj has been supplied Guardian Glass, an architectural glass producer for commercial and residential markets. This is by far the very largest order bagged by Guardian glass plants in Germany and Luxembourg.

Guardian glass offers outstanding energy efficiency and total design flexibility, while meeting both technical building requirements and environmental needs. Burj Khalifa features more than 1.8 million square feet (174,000 square meters) of Guardian SunGuard Solar Silver 20 and Guardian ClimaGuard NLT Low-E. Altogether these Guardian products offer superior solar and thermal performance.

The high performance glasses used provide an anti-glare shield from the strong desert sun, and a high light reflectance to keep the interiors from overheating. They also withstand extreme desert temperature swings and strong winds.

Guardian SunGuard

Guardian SunGuard Solar Silver 20 which gives a silver appearance is produced by patented silacoat process, offering a combination of practical benefits and enhanced product features including enhanced chemical and mechanical durability and also excellent energy performance and coated glass quality. It also provides uniform reflection and transmission of colours. This glass can be tempered, heat-strengthened and curved. Solar Energy and visible light performance of the SunGuard Solar Silver 20 is as follows:

Solar Energy:

Direct Transmission: 15 %
Direct Reflection: 33 %
Absorption: 52 %

Visible Light:

Transmission: 20 %
Reflection Outside: 35 %
Reflection Inside: 25 %
Colour Rendering Index: 88 %

Guardian ClimaGuard

Guardian ClimaGuard NLT Low-E regulates the interior temperature cool when it is hot outside and vice-versa. ClimaGuard Low-E blocks up to 50% more unwanted solar energy than standard clear glass, and up to 40% more than even dark tinted glass. As a result, air conditioning expenses are lowered while providing a more comfortable living environment. ClimaGuard Low-E also blocks nearly twice as much harmful radiation as clear glass, extending the life of woodwork, carpets and furnishings, while still allowing plenty of natural sunlight to brighten interior spaces.

Guardian is also supplying the glass for the Burj Residence project, six towers that surround the Burj Khalifa. The Burj Residence will use Guardian SunGuard HP Green 63, produced at Guardian’s Rayong, Thailand float glass plant and coated at Guardian’s Bascharage, Luxembourg float glass plant.

SunGuard High performance glass delivers medium to high visible light transmission and moderate reflectivity together with maximum energy savings that meet or exceed energy regulation requirements. SunGuard coating with a green substrate reduce glare and improve visual comfort and also offers energy control option to provide the optimum internal environment.

Satin Glass

Satin glass was first made as decorative pressed glass in England and the United States during the 1880s. Satin glass is similar to milk glass in that it is opaque, and has decorative surface patterns moulded into it; however, satin glass has a satin, rather than glossy surface.

Satin glass is typically tinted with a pastel color, blue being the most common. Satin glass is also used to impart privacy where full transparency of glass is undesirable. Satin glass arouses a lot of interest through its unusual feel and appearance.

Satin glass is nothing but any glass that has been chemically treated to give it a satin finish. Satin Glass is made by treating finished glass products with hydrofluoric acid to remove the shine. Normally clear glass is dipped into hydrofluoric acid, which eats away the shine and dulls the surface. The finish itself is both visible and most certainly recognizable by the touch. The term "satin glass" is frequently used to refer to a collectible type of pressed glass.

Satin Glass looks sandblasted but is actually acid-etched. It reveals finger prints less than real sandblasted glass. In certain varieties of satin glass such as “Clear Shield” or “Diamond Fusion”, finger prints are even less visible.

Good pieces of satin glass feel actually like a piece of fine satin cloth. The translucent quality of satin glass make it especially desirable for use in lampshades; a form of satin glass still has a universal practical use in “pearl” or frosted light bulbs. Satin glass is typically used as art glass in windows or doors.

Acid-Etched Glass

Acid etching is a process that uses a strong acid to cut into another substance. It is used for both industrial and artistic purposes. For example, etching can be used to prepare flooring like cement for painting or refinishing, while artists use it to create detailed pictures on metal or glass.

Acid-etched glass has a distinctive, uniformly smooth and satin-like appearance. Acid-etched glass admits light while providing softening and vision control.

Origin of Acid-etched glass

During the middle ages, acid glass-etching was somehow clouded with controversy since its acid medium, hydrofluoric acid, caused too much of a health risk to the artisans. In fact the acid was so potent that users were found to have been poisoned even by its mere fumes. Accidents most often happened where a skin contact with the acid dissolved into the tissues, which later resulted in mutilation or loss of the artisan’s fingers. As a result, acid etched glass craftsmanship lacked refinement and thus lost its luster as an art collection.

Now, there are etching tools such as swivel knives, pick knives, adhesive masks aside from the squeegee which makes it possible for an ordinary person to work on acid glass-etching.

Acid-Etching Glass production

Acid etched glass is produced by acid etching one side of float glass. Etched glass is created by cutting a design stencil that is made of an abrasive resistant material, such as vinyl or rubber. The resulting stencil is called a resist. The resist is then secured onto the glass to be etched. A blaster gun, powered by an air compressor, is used to bombard the glass with the abrasive. Every part of the glass that is not covered by the resist will take the frosted effect while the parts protected by the resist will remain clear, thus producing a piece of etched glass.

Etching glass - Hydrofluoric acid

Glass is etched by hydrofluoric acid, or by hydrofluoric acid gas. The gaseous acid has the property of producing a surface which resembles ground glass in its appearance; the liquid acid produces clear etching. Etching glass, therefore, consists of 2 distinct branches. First, the production of a dull image on a clear surface (when the gas is used) and second, the production of a clear image on a surface previously ground or dulled by means of the liquid acid.

The glass plate to be etched is cleaned and gently warmed until hot enough to melt wax. The surface is then covered with an equable layer of white wax, by rubbing the wax over it. When cold, the design is cut out of the wax with a graver. A shallow leaden trough, about the size of the plate (but a trifle smaller) is obtained, into which is placed a small quantity of finely - powdered fluorspar. This must be weighed and then gently sifted over the bottom of the trough. To every 2 parts by weight of fluorspar add 3 of good oil of vitriol. Stir quickly with a wooden stick, and place on the hob or other warm place. Vapour will soon rise.

Now the trough is removed and covered over with the waxed and graved plate, wax side downwards. In a very short time, the acid will have etched the bare portions of the glass. When sufficiently etched, remove the wax by melting. To prepare the liquid acid for clear etching, place 2 parts fluorspar and 3 of sulphuric acid in a leaden retort, the tube of which must dip into a leaden bottle half - filled with water.

Apply heat to the retort as long as the water will absorb the fames generated. If a ground glass be prepared with wax, as above, and a ledge of wax or putty be made round it, on pouring the liquid acid on the plate, clear lines on the dull ground will result; or a "flashed" colored glass may, by the same means, a colorless picture on a colored ground can be done. The sheets of clear glass may themselves be dulled by exposing them, without previously waxing, to the fumes of the acid gas.

Applications

Acid etched glass is perfect for both interior and exterior applications. Architecture and construction, like in houses, restaurants, hotels, commercial buildings, etc. They are found in many residential applications such as home decoration like furniture components. Some of the suggested applications are:

• Interior partitions
• Railings
• Shelves
• Shower and bath enclosures
• Doors and windows
• Glass walls
• Kitchens
• Interior and exterior doors