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These days, energy efficiency is one of the key indicators used to evaluate the sustainable character of buildings.

Certification schemes are being developed in many countries to evaluate and rate such building energy performance.

Intelligent façades incorporating aluminium systems can decrease energy consumption in buildings by up to 50%.

The key feature of these intelligent buildings is their constructive interaction with the exterior, markedly reducing energy demands in heating, cooling, ventilation and lighting.

This is achieved through numerous techniques and processes including photovoltaic, optimised glazing systems, intelligent ventilation mechanisms and appropriate light and shade management.

The use of insulated aluminium shutter in cold periods will also limit heat losses at night.

In hot seasons, solar gains need to be minimised in order to optimise the occupants’ thermal comfort or to reduce the air conditioning needs.

As a result, in warm regions, coloured glazing with low solar gains should be used with associated shading devices, such as solar blades or shutters.

In region where winter and summer temperatures vary significantly, it is crucial to design shading devices properly in order to optimise the solar gains of the glazed surfaces.

For a material or product to be considered green, it should have low impact on the environment and therefore protecting and conserving the natural environment and its resources.

Aluminium can be considered as green material.

Aluminium is recyclable, sustainable, and versatile; three key qualities for any material being used to construct a green building.

Aluminium has proven to be one of the most important materials in successful recycling programs.

Aluminium has high scrap value, widespread consumer acceptance, and aluminium recycling enjoys significant industry support.

In addition to recyclability, other eco-friendly qualities that aluminium flaunt while meeting green building requirements include its light weight-to-strength ratio, which allows for the reduction in weight of materials, and its extrudability, which accommodates off-site fabrication.

From the sustainable point of view, aluminium building products or structures provide excellent credibility when the long-term approach is being adopted.

Despite the initial high cost and the great amounts of energy consumption during production, the special features of aluminium enable sustainable performance when the whole service lifetime of the structure is considered.

Aluminium building material has a very long life cycle, ranging from 30 to 50 years, and due to this durability, the maintenance costs are very low over the lifetime of the structure. In addition, the majority of alloys used in construction are weather-proof and corrosion resistant, thus a long serviceable lifetime is assured[1].

Aluminium structures are easy to dismantle and transport and the recycling process to produce secondary ingot from scrap requires only 5% of the input energy required to produce primary aluminium and with no loss in quality. Currently, a recycling rate of 85% is achieved in the building industry[2].

Aluminium can be used for both structural and non-structural applications.

The lightness of aluminium is a characteristic that contributes to its wide structural application and provides many advantages in transportation and erection, especially for prefabricated systems.

In addition, in structures like swimming pool roofs, harbour elements, and river bridges, which are characterized by humid environments, the choice of aluminium alloys is preferable[3].

In these cases, due to the corrosion resistance of aluminium alloys, the sustainable feature of durability is achieved and the maintenance costs are less compared to other materials such as steel. In particular, the introduction of the latest version of Eurocode 9, where specifications on the corrosion tendency of aluminium and useful recommendations for selection and protection of aluminium alloys according to various exposure conditions are provided, contributes also to the wide use of aluminium in such structures[4].

There are also facade and roof systems where aluminium is used in window and glazing frames and glazing spacers.

The function of these systems is to provide daylight, visual contact between the exterior and the interior, provide protection against the weather (rain and wind), provide passive solar heating gains, help keep interior thermal comfort, and keep the energy use for operation at a minimum.

Regarding shading systems, there are venetian blinds, screens, overhangs, side fins and others.

Aluminium also used in lamellas, screens and fins. The function of these systems is to prevent glare and overheating and thereby minimize the energy use for space cooling.

Nowadays, facades that incorporate aluminium systems which can decrease energy consumption in buildings by up to 50% have just started to appear in European constructions.

As construction industries facing numerous environmental issues from its direct impact on climate change to its choice of materials and its methods of waste disposal.

The entire life cycle of a building must be considered when assessing these issues as well as environmental considerations that need to be balanced against the realities of design, function and economy.

When choosing the optimum material for each building, an approach which takes account of the full lifetime of the material should be adopted, covering construction, use, maintenance and disposal phases. Aluminium is one of the best choices for the job.

Source : Green Building World-Aluminium and Aluminium Extruders Council

(this article written for 1BINA.my)

[1] TALAT “Training in Aluminium Application Technologies”; European Aluminium Association (EAA): Brussels, Belgium, 1999.

[2] Maydl, P. Structural Sustainability—The Fourth Dimension? Struct. Eng. Int. 2006, 16, 268-269.

[3] Aluminium Structural Design; Mazzolani, F.M., Ed.; CISM International Center for Mechanical Sciences: Udine, Italy, 2003.

[4] prEN 1999−1−1, Part 1−1. Design of Aluminum Structures: General Structural Rules; European Committee for Standardisation: Brussels, Belgium, 2006.