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The benefits of aluminium for solar shading
There is no doubt that aluminium is the perfect material for solar shading. For that reason it has brought about a revolution in the industry but, almost equally importantly, it has impacted on the aesthetics of modern buildings because architects frequently use shading systems to added advantage as a bold and dynamic element in the overall design concept.
Offering the very real benefits of being lightweight, non-corroding and easily fabricated, aluminium makes possible the creation of systems that have an elegance and lightness of look which would simply be unachievable in any other material.
The lowry
An example of the versatility of aluminium based solar shading products can be seen at The Lowry, Salford’s new arts theatre and gallery centre. Aerofoil fins from solar shading specialist Levolux fulfil a key role in providing shading to large areas of glazing while playing an important part in the building’s highly individual appearance. On one elevation 500mm fins are used horizontally to give a dramatic ladder-like appearance while, on another, the same fins run vertically to provide protection from low afternoon sun.
To avoid deterioration to the works of art in the building’s exhibition space, dim-out of around 97% was required to a series of roof lights so Levolux Skyvane systems, with interlocking 75mm wide aluminium slats, were installed internally.
Skyvane can be employed internally or externally and its design and operating efficiency is almost totally reliant on aluminium and, as a result, it weights just 2.5kg per m², a figure which it would be impossible to equal in any other comparable material.
high quality and intricately shaped profiles
A very real benefit of aluminium is the ease with which high quality and intricately shaped profiles may be manufactured. These are extruded in one piece making possible not just the creation of louvres but hollow and therefore lightweight sections which are perfectly suited to the production of aerofoil fins for use in solar shading systems.
Currently one-piece extrusions up to 500mm wide are common while larger sizes are now becoming available. Wider aerofoil fins are also produced by making the extrusions in a number of parts which are then “snapped” together. Another method of creating such fins was employed to achieve a dynamic solar shading solution at Arlington Estates’ Theale Business Park, close to junction 12 of the M4.
Levolux provided solar shading at ground, first and second floor levels by using bespoke 600mm wide fins set at 45° one above another. As the fins are particularly wide they are fabricated in a similar way to an aircraft wing. Each 3m long fin has two 90mm aluminium tubes which form a nosing at each edge, at either end are shaped aluminium plates while the main body of the fin consists of perforated aluminium sheet. The perforations allow some light to filter through thus lightening the building’s interior.
weight advantages
The metal’s light weight offers very real benefits not only when finally installed as a shading system but in every stage from factory to site, since it makes for ease of handling and installation while transportation is relatively cheap. When applied to a building the weight advantages are clearly evident because of the implications of loading and stress on the structure itself.
A long established means of solar shading is through the use of venetian blinds but here again aluminium plays a key role in the present generation of products because of its outstanding properties. These become all the more important with external systems that are exposed to the full rigour of the elements.
The strength of the material means that it has applications beyond fins, louvres and slats and can be used for elements such as walkways. Compared to steel, it is also easy to work and cut and enables a better finish to be achieved since it is smooth and clean.
Faculty of Divinity, University of Cambridge
Nowhere is the use of aluminium more apparent than at the new Faculty of Divinity building at the University of Cambridge where, together with Edward Cullinan Architects, Levolux employed mill finished aluminium in creating a brise-soleil. The metal will naturally oxidise and the system plays a striking aesthetic role in the overall design concept while shading the ribbon windows and shedding rainwater away from the building.
As well as being used in a natural mill finish, aluminium may be anodised, powder coated or have a highly durable PVF type coating applied. Above all it does not corrode and high-grade stainless steel does not react with it. Bimetallic reactions are rare but, in cases where they may occur, simple barriers such as nylon or neoprene bushes are employed.
From an environmental viewpoint aluminium is a recyclable material and much of the metal used in producing the extrusions for sun shading systems comes from such sources. What is more, the coalition of aluminium and solar shading can represent significant capital and energy saving cost benefits because of the reduced reliance on air-conditioning to reduce heat levels within buildings.