Volume 50, Issue 11 - November 2015

NewsAnalysis:SUNSHADES

The Greener Side: Sunshades Are About More than Just the Looks

The demand for sunshades has been traditionally driven by one primary attribute—aesthetics.

Yet with an ever-increasing focus on green building practices and more stringent energy codes during the past few years, building owners and architects are realizing the many benefits that can come from incorporating sun control devices into their design.

“LEED certification, green construction codes and standards are driving architectural design decisions,” says David Warden, enerGfacade brand manager, YKK AP America. “Although the prescriptive requirements for solar heat gain coefficient (SHGC) have not changed significantly since the codes merged to become the International Code Council (ICC) in 2000, LEED certification and the 2012 IgCC, and ASHRAE 189.1-2011 encourage and require going beyond the prescriptive requirements for SHGC.”

He adds that architects understand sunshades lower SHGC, reducing cooling loads of the HVAC system and making cooling more efficient.

Tom O’Malley of Clover Architectural Products notes that, based on solar studies he’s assisted on and performed, sunshades provide more than just cooling effects on buildings, too.

“When used properly, they can redirect sunlight into the building to reduce or eliminate the need for lighting, they can create specific shadows based on the time of day or time of year to block sunlight that would otherwise create glare, or introduce heat into the building, and they can enhance the aesthetics of the building façade,” he says. “Sunshades are a small, but important, part in achieving LEED certification, as well.”

Aesthetic appeal is still a major driver in the sunshade market, but architects and building owners are increasingly utilizing the product to help meet energy efficiency and other green building needs.
Warden adds that architects have also discovered that sunshades can enable the use of very clear glass, allowing for more glass options and better views for occupants.

Brian Clifford, director of architectural railing and metals at C.R. Laurence-U.S. Aluminum, says the primary benefit of sunshades is still design and their ability to add a third dimension to a building. However, he says the main difference between today and 15 years ago “deals with the success rate of the shades staying on a given building throughout the project lifecycle. This has been greatly influenced by new codes and LEED standards.”

Clifford adds that the demand for integrated systems is on the rise, because architects are looking for a single manufacturer to supply both the curtainwall/storefront system and sunshades. And with sunshades becoming more popular in recent years, particularly when integrated with curtainwall and storefront systems, he expects that organizations such as the ICC, International Building Code and/or the American Architectural Manufacturers Association will begin implementing codes requiring laboratory testing.

“These tests would incorporate real life situations such as interaction with window cleaning equipment, dynamic water penetration testing, and snow falling from sunshade to sunshade in stacked applications,” says Clifford. “This could affect the sunshade manufacturers who install their sun controls to curtainwall and storefront systems from other manufacturers.”

O’Malley says the use of perforated panels on sunshades has been one of the more recent advances to filter sunlight. Another recent development is infusing thermal barrier technology into the anchoring system, which, according to Warden, has allowed sunshades to be attached to curtainwalls without increasing the U-factor of the host wall.

“Historically, adding a sunshade without a thermal barrier can decrease the wall’s performance by as much as 5 percent,” says Warden. “For example, a curtainwall with a single band of sunshades, that achieves a U-factor of 0.45, will become 0.47 without a thermal barrier. This can be compounded when a wall contains more than one band of sunshades. Non-thermally broken anchor systems reduce the ability of aluminum framing systems to resist condensation.”
Sunshades serve a variety of purposes, including controlling solar heat gain and managing daylight into interior spaces.
Sunshades continue to prove themselves as much more than a design element and have undoubtedly seen increased demand in recent years. YKK AP, for example has seen a “significant increase in sunshade inquires in recent years,” says Warden, adding that close to 30 percent of his company’s engineering reviews include analysis of some sort of sunshade device.

—Nick St. Denis



USG
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