Glass Technology

Glass remains one of the most popular facade materials in the GCC.

How are glass manufacturers responding to the growing demands for sustainable buildings? Construction Week investigates how nanotechnology is making an impact in the sector.

Take a drive through any of the major business and commercial areas of the Middle East and virtually all of the buildings you pass will be clad, to a high degree, in glass. Whether coloured, clear or reflective, glass remains one of the most popular facade materials in the Middle East.

But with the growing demand for sustainable buildings, can a material that is ultimately designed to let light, hence heat, into a building remain a feasible option when this can increase the problems of thermal solar gain and glare? The latest nanotechnology developments in glazing design may mean the answer to this question is yes.

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Creating coatings
Within the glass industry, nanotechnology is seen as “an important source of new performance” states Pilkington Glass. In short, it involves the production and application of microscopic coatings onto glass that can make profound changes to its natural properties. 

With traditional glass, the greater the transparency the more light will pass through, which means more heat energy entering a building. This also means the need for greater mechanical cooling to maintain comfortable indoor temperatures. And in a region where the ambient temperature regularly reaches 50°C, the danger of overheating, and an increased need for air conditioning, becomes even greater.

The development of special glass coatings means that a high level of light gain can now be achieved with a significantly lower subsequent thermal heat gain. And the region’s architects and contractors are now using these products to the advantage of both their designs and the end-user.

New developments in the field mean that yet more benefits can also be gained through the careful application of coatings, further widening the future scope for glass use.

So what new coatings are on offer? Anti-bacterial, self-cleaning and photovoltaic versions are among those that have seen recent advances in technology.

“The products that have just come out range from anti-bacterial coatings, which attack bacteria, to passive anti-bacterial coatings that don’t allow mould to grow,” reports Emirates Glass technical manager Steve Lipscombe, “This is good news for hospital contracts, commercial kitchens, hotels and anywhere else [the general public] may be eating,” he adds.

Spectrally selective products such as coatings with double and triple silver layers are also being introduced to the market. These coatings block out uv light, while letting visible light into a building, so thermal gains are reduced while a high light transmittance is achieved.

“The latest development in coatings is triple silver and most new projects are asking for U-values of 1.1 and 1.4; the triple silver can address the 1.1 range, while the double silver can cover the 1.4 U-values,” explains Jean Lelievre, director, product and technical department, Al Abbar Architectural Glass (AAG).  “This 0.3 difference in U-value is quite big and translates to a lot of wattage per m²,” stresses Lelievre.

Such coatings cannot be used in all applications however, and as with all glass coatings a holistic approach should be taken when selecting the products for an individual project.

“The duty of the glass industry is not just to design and develop these coatings, but to educate the design and contracting industries as to where to use them. There is a right and wrong place to put each type, and there is no point in using certain types of glass if they do not suit the application. We don’t just supply glass, we ask a lot of questions first to make sure that the glass chosen is right for the application,” stresses Lipscombe.