Aluminum’s inherent strength, recyclability and versatility combined with the extrusion process make aluminum a popular (and economical) material for the building and construction industry.
Strength
Aluminum can be used for small frame applications such as operable windows while also accommodating large spans between floors. When used as part of a punched opening window the unit can be managed by one to two workers while providing the structural integrity required.
Strength-to-Weight Ratio
For commercial applications, aluminum provides the necessary structural properties with a high strength to weight ratio. The ability of aluminum to withstand wind loads and still retain its shape is beneficial in maintaining structural integrity while resisting water and air infiltration. This also allows the building to keep its desired appearance.
Aluminum provides enough stiffness to allow deflection with integrity and also allows enough deflection to alleviate strain on connections. For example, when it comes to blast resistance design, frames that are too stiff will blow out of an opening. Whereas some flexibility will allow a frame to maintain its integrity within an opening by the way it transfers loads to the surrounding building structure.
Reduced Shipping and Installation Costs
Since aluminum weighs less than other materials commonly used in commercial applications, shipping costs will be noticeably lower. For smaller shipments the weight reduction will allow more flexibility in delivery methods. Costs are also reduced because of the ease of handling prior to and at delivery.
Likewise, installation will typically be easier and less costly. The handling of large sticks of aluminum can be done with one or two individuals. Other heavier materials could require the use of cranes. Once in place, slight adjustments to the fenestration are also easier with aluminum due to its lighter weight. The need for a crane requires added space besides the added cost. There is also the risk of liability due to heavier loads.
Design Flexibility, Affordability
Aluminum extruded profiles can range from simple shapes to very complex, intricate shapes. Most architectural profiles range from simple to sophisticated as well. More than 80 percent of the aluminum extrusions used in window, door storefront and curtain wall applications fit within a 10-inch circumscribing circle.
Economical Tooling Costs and Quick Lead Time
The extrusion tooling required to produce these shapes is very budget friendly, usually ranging from $500 for simple, solid shaped profiles, up to $5,000 for a complex, multivoid hollow shape. Typical lead times for this tooling run from two to three weeks. Aluminum extrusion tooling can also be revised, in many cases, when minor changes in the profile design require modification, which is a real advantage in managing costs.
Recyclability
Aluminum is sustainable. Aluminum is a noncombustible and natural material. It is the third most abundant element in the Earth’s crust (in the form of bauxite), next to oxygen and silicon. Aluminum is environmentally friendly and nontoxic, even when subjected to high temperatures. It is 100 percent recyclable regardless of any applied finish and can be recycled repeatedly while still retaining the same material physical properties.
According to material flow analysis by the International Aluminum Institute, 75 percent of all the aluminum ever produced in the world is still in service today. Delft University of Technology found that “95 percent of the aluminum used in B&C [building and construction] market is recycled at the structure’s end-of-life.” Because of this, and the desirability of the high scrap price, it reduces its environmental impact by not being deposited into landfills. Recycling aluminum takes only about 5 percent of the energy required to make primary aluminum, seriously reducing greenhouse gas emission.
Recyclable
According to the Aluminum Association, aluminum is one of the most commonly recycled post-consumer metals in the world.
The Aluminum Extruder Council reports that aluminum can be recycled and reused over and over without losing any of its characteristic attributes. It takes four pounds of bauxite (raw material) to make one pound of aluminum and every pound of recycled aluminum saves four pounds of ore. Since the first recorded year of aluminum production in 1893, an estimated 700 million tons of aluminum has been produced of which 400-500 million tons (three-quarters of the output) is still in productive use.
When aluminum is refined (or recycled) in North America, the vast majority of the electricity is produced by clean, renewable hydropower. According to IAI’s 2015 report, Life Cycle Inventory Data and Environmental Metrics for the Primary Aluminium Industry, hydropower is used for 74 percent of the total energy to recycle aluminum and 100 percent in Canada.
Recycled aluminum also helps to achieve the recycled LEED® requirement MR4 (materials with recycled content such that the sum of the post-consumer recycled content plus one-half of the pre-consumer content constitutes at least 10 or 20 percent (based on cost) of the total value of the materials in the project.)
Sustainable
At the end-of-life stage in a building, aluminum is 100 percent recyclable and may be reused without any loss in mechanical attributes, saving on raw material costs.
End Use Shipments of Aluminum Extruded Products, a North American survey conducted jointly by the Aluminum Extruders Council (AEC) and the Aluminum Association, shows 1.97 billion pounds of aluminum were used in 2016 for the building and construction industries, primarily in window, door and curtain wall products.
Recycled materials use natural resources and need to be used effectively again to avoid impacts on the planet. Furthermore, recycling creates jobs.
Benefits of Aluminum Recycling (Annually)
- Equivalency of about 70 million barrels of crude oil of energy is saved – enough oil to feed U.S consumption for three days or nearly one day of the world’s oil supply
- Approximately 2.4 million meters2 of land is saved
- More than 45 million tons of fresh and sea water use is avoided—enough water to provide for the needs of New York City’s 8 million people for 10 days
- Approximately 7.5 million tons of solid waste is avoided
- About 27 million tons of CO2 greenhouse gas emissions is avoided—equivalent to eliminating five large (1,000 MW) coal-fired power plants
Versatility
Photo by Travis Mark, courtesy of Apogee Enterprises
Aluminum’s versatility has long made it a preferred material in many construction projects. Combined with the fact that it is available in numerous shapes and a spectrum of colors, its structural attributes allow aluminum to be used in nearly every application – from solar optimization in products like sun shades, light shelves and skylights to adding comfort in the most elite homes in the form of folding walls and sunrooms.
When utilized in the architectural design elements found in stadiums and the world’s largest buildings, confidence in a fenestration’s material choice is a mandate, which is why aluminum has been used in these types of structures for decades, but its ever evolving thermal performance, finishing capabilities and recyclability along with numerous additional green attributes continue to make it a cost-effective, sustainable choice in all applications.
Focus in other areas include reducing air emissions, water discharges, solid waste and other areas of recycling and purification which include but are not limited to: removal of caustic (Sodium Hydroxide) from the air caused by die shop scrubber units, recycling of acetone and xylenes used in paint lines to clean and flush out lines, use of caustic etch recovery units in the anodizing lines to dissolve aluminum from the caustic thus allowing the caustic to be continuously re-used, use of thermal oxidizers on the paint lines to remove the Volatile Organic Compounds (VOCs) from the air prior to emission and recycling of packaging materials.
The Aluminum Association’s Voluntary Aluminum Industrial Partnership (VAIP) program has reduced U.S. emission intensity of PFC (perfluorocarbon) from aluminum smelting by more than 80 percent from 1990 levels.
The Aluminum Material Council (AMC) of AAMA has worked diligently authoring standards so that the end user can be assured that they are utilizing the right aluminum product for their application. These standards continue to evolve as the market demands. Recently, hurricane and blast criterion have come to the forefront of fenestration requirements. With the addition of AAMA standards, aluminum products have helped to pioneer the way forward to government and county code compliance. AMC exists to make sure that whatever the next generation of requirements demand you can rest assured aluminum’s versatility will continue to make it a secure, cost effective choice in those applications.
