New solar shading panels made from lightweight, durable Lexan Exell D polycarbonate (PC) sheet from SABIC’s Innovative Plastics strategic business unit, are making a major contribution to energy efficiency and comfort at the new flagship City of Westminster College in central London.
The high-performance panels filter out direct sunlight to minimize solar gain and glare on computer screens. They also admit generous amounts of natural light and are expected to significantly reduce building energy requirements, and maintenance and lifespan costs. SABIC’s ongoing investment in environmentally responsible materials for the global building and construction industry is helping customers meet their sustainability goals with new eco-progressive products.
“The success of this project called for an advanced material that could deliver a combination of high-performance properties: excellent aesthetics, insulation, ultraviolet protection, flame retardance, durability and light weight,” said Simon O’Hea, director, Colt Group Ltd. “Based on our history of working with SABIC, and after researching all our options, we recommended Lexan Exell D sheet to the architect. SABIC supplied the customized sheet with the precise balance of light transmission and heat reduction, greatly enhancing the building’s energy efficiency while adding to the striking architectural impact of the building’s design.”
The distinctive, cantilevered building for City of Westminster College – a leading continuing education college offering over 200 vocational and academic courses to students – was designed by Schmidt Hammer Lassen architects to minimize energy usage and carbon footprint. This sustainability strategy includes full-story, vertical solar shading panels fabricated by Colt using custom-colored, translucent Lexan Exell D sheet, which flank the windows on the east and west façades.
The solar shading panels, also referred to as a “brise soleil” system, are fabricated by framing 3.5 m by 5.76 m rectangles of solid Lexan Exell D sheet. They are mounted on either side of the building’s windows on the façades that receive major exposure to sun. SABIC provided color-matching services and technical support to Colt, and backs the material with a 10-year limited warranty against breakage, yellowing and loss of light transmission.
Weighing only half as much as glass, Lexan Exell D sheet reduces the amount of material required for structural supports. The PC sheet also provides high impact strength (250 times that of glass) and flame retardance (compliant with the European fire standard EN 13501-1) for safety, and complies with glazing security impact resistance according to Pr EN 356. Other key properties are dimensional stability; ease of handling and installation; and resistance to yellowing, graffiti and breakage.
“Specialty Lexan sheet products can play an important role in the overall sustainability of commercial and residential buildings that would otherwise call for air conditioning by reducing infrared radiation,” said Jack Govers, general manager, Specialty Film & Sheet, Innovative Plastics. “At the same time, our Lexan sheet solutions allow architects to create designs that feature high natural light levels, which create a pleasant working and living environment. These materials can help architects and designers succeed in the lucrative sustainable building space and have potential to contribute to eco certifications.”
SABIC’s robust Lexan PC sheet products are lightweight, flame-retardant materials, available in monolithic and multiwall configurations, which are used worldwide for roofing, cladding and glazing massive stadiums, hotels and other impressive structures. They are designed to allow penetration of natural, filtered daylight into living areas without heat build-up.
Lexan sheet products can address performance challenges such as color fading, marring and scratching, cracking, rusting, and paint peeling that occur with metal, wood, stone, glass, and other materials. They can be designed with capabilities such as double-sided ultraviolet protection and special coatings that provide a self-cleaning feature or protection against graffiti.
Lexan sheet can be cold formed and bent into complex shapes using conventional equipment, and can be enhanced with colors, textures and special effects. Further, the lighter weight of plastics compared to glass allows these materials to be used in large structural components. Lexan sheet offers extremely high impact resistance to minimize the risk of breakage – even when subjected to violent blows by heavy objects.