Quantifying aluminum’s green credentials

The Edith Green-Wendell Wyatt Federal Building, constructed in 1974, is now sheathed in a high-performance skin of shading elements and reflecting aluminum reeds and panels in bright silver, bright white, and pewter colors, reducing the building’s energy consumption by 55 percent.
Photos © Brett Drury. Photos courtesy PGE

Pursuing third-party green certification due to concern for the environment and the health and well-being of tenants is not the only consideration, although it is of paramount importance. Owners may benefit financially as well. Several studies have demonstrated LEED-certified buildings may demand higher rents and increased market value. (For more, see articles from Bentall Kennedy Group or San Diego Union Tribune—respectively, www.bentallkennedy.com/news-2015-10-06.php and www.sandiegouniontribune.com/business/growth-development/sdut-green-buildings-outperform-vacancy-rental-rates-2012sep05-htmlstory.html.)

Being able to demonstrate the business and financial benefits of their green building investment is important to owners. Measuring energy efficiency and energy savings in retrofits is one obvious solution, as is achieving LEED certification. However, ‘soft’ measurements also can be of value. For example, asking employees and tenants through surveys specifically about the building’s green initiatives (e.g. thermal comfort, daylighting, and ventilation) may provide anecdotal evidence a green building offers a more pleasant work environment.

Owners and developers who do try to quantify the impact of healthy buildings report improved employee satisfaction and engagement, the ability to lease buildings quicker, and a potential positive impact on the building’s market value.

Determining the optimal combination of building performance and functionality depends heavily on the building’s fenestration system. In turn, the fenestration heavily depends on use of highly engineered framing to meet structural challenges, as well as current and foreseeable stringent energy codes. Aluminum provides the sustainability, structural integrity, and inherent beauty to do the job well.

Anodizing is a chemical process that converts the surface of the aluminum to an oxide finish. This is actually a naturally occurring phenomenon, but it can be controlled in manufacturing processes. Anodizing consists of three processing stages.

  1. Pretreatment
    Pretreatment cleans the surface and provides an initial chemical treatment. The chemical treatment can result in different levels of etching depending on the requirements, or could result in a surface with some degree of reflectivity.
  1. Anodizing
    Anodizing occurs when an electrical current is passed through an acid bath in which the aluminum has been submerged. The electrical current is passed between a cathode; aluminum acts as the anode in the process. It is in this stage the coating thickness and surface characteristics can be controlled to meet project specifications.
  1. Post-treatment
    During the post-treatment process, dyes can be used to fill the pores of the metal. Many of these colors will be fade-resistant. The anodic film is normally sealed in a hot-water bath that closes the pores in the metal through swelling.

Rich Rinka serves as the American Architectural Manufacturers Association’s (AAMA’s) technical manager for standards and industry affairs. Before coming to AAMA, Rinka worked in the industry as a field technical engineer for a component supplier, and also served as chair of the AAMA 800 Maintenance Committee. During his time in product development for the automotive industry, he developed (and still holds) four patents related to sealants. He can be reached at rrinka@aamanet.org.

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