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DESIGNING WITH LOUVERS

As stated earlier, louvers have many functional benefits, but they provide architects with an opportunity to enhance the architectural interest of a building. That’s because louvers have transcended their utilitarian origins to become an integral part of the architectural language.

Whether it's a sleek, minimalist look or an intricate and decorative pattern, lovers allow architects to enhance the aesthetics of a commercial structure. While not typically considered an obviously sexy design feature, the right louvers can add an economical design element to the facade, adding contrast to a facade or blending with it.

After architects have determined their needs, the design options are wide open–from color, texture, size, and design. Some manufacturers offer louvers in standard colors or up to 500 resin-based and metallic finishes, while other suppliers offer color-matching and wood-grain patterns. Architects may also specify intricate custom shapes.

More than simply squares and rectangles, louvers can be specified in almost anything an architect needs, allowing units to fit the design of the building and not the building to the louver limitation. But architects must remember that changes in louver shape will alter its performance.

AMCA's standardized test methods only apply to louvers as they are intentionally designed, but do not account for louvers that have decorative screens placed on them as an after-market option. Decorative screens change the air flow and performance of the louvers, which can create an issue for the project when trying to meet both performance and aesthetic goals.

The critical requirement for the designer or engineer is to ensure the manufacturer will provide a complete system, as specified, to the end user and be able to test the product to AMCA standards. This will allow for the inclusion of decorative elements, like screens in front of the louver that also meet or exceed the performance expectations. Not all manufacturers are capable and willing to provide this next level of assurance, which makes specifying a product that has full support of the manufacturer especially important.

For example, if a louver with an AMCA seal rating for air performance, the seal will not apply to the louver if a decorative perforated panel is added to the front of the louver. One thing to note is that wind-driven rain and extreme-weather defense louvers are not available with custom-shape options other than square or rectangular. Because they are designed for heavy rain and severe winds, their design cannot be modified.

Specifiers and architects typically must decide how they want the louvers to be used in a project, as there are many options. Specifiers may choose recessed- or hidden-mullion options, which can remove the visible divisions between louvers, creating a continuous line for panels that are linked together. Hidden mullions are completely concealed behind the blades, but the application may affect the louver's wind load capabilities, as the blade supports will not have the same structural integrity of a standard frame louver. As a result, the application will be affected by high winds. Architects should consider where such an application will be installed before deciding. Architects use louvers in a variety of project types and in ways to solve problems creatively.

Photo courtesy of Lester Ali Photography

The Rose Hill building in Manhattan designed by CetraRuddy, utilized custom-cut metal screen covers over louvers.

LOUVERS IN THE REAL WORLD

One example of adding louvers into a project to blend classic charm with contemporary performance expectations is Rose Hill, in New York City. Owned by the Rockefeller Group, Rose Hill is a new, 46-story, thin residential building in Manhattan that has the unique design attribute of a dedicated mechanical floor at both the top, and bottom of the building. To facilitate air to flow in a circular manner to both mechanical spaces, thus keeping the building and its occupants healthy, louvers were specified to be installed at entry-level near the occupant entrance.

While the louvers would supply ample fresh air required for the building, the challenge was finding a way to incorporate the equipment into the ground-level facade in a tasteful way to match the desired Rockefeller Center stylized theme.

The solution was to employ custom cut metal screen covers placed over the louvers, to blend in with the rest of the facade and still be manufacturer tested for Pressure Drop and Wind-Driven Rain. CetraRuddy, lead architectural firm on the project, were led by Senior Associate Project Designer Charles Thompson, LEED AP, and leveraged the chevron as a common design element for the project. The facade at the base of the building, railing, as well as the custom metal covers on the louvers all carried the chevron pattern, creating a uniform and consistent visual aesthetic.

Another project that benefited from the flexibility and resilience of louvers was the Children’s Hospital of Philadelphia. The Children’s Hospital of Philadelphia (CHOP) is the nation’s first hospital devoted exclusively to the care of children, and since 1855 has had many notable firsts in pediatric medicine.

When an update to the facade was commissioned, architectural firms Ballinger Architects and Kohn Pedersen Fox were faced with two challenges. With the increase in frequency and severity of extreme weather events, especially the harsh storms that occur on the East Coast, the louvers specified had to be up to the task of enduring extreme weather conditions. Also, the louvers needed to blend seamlessly with the design of the building. The solution was a hearty storm-resistant rated system that wrapped completely around the building’s facade. Seven-inch louvers were specified to allow for ample flow of free air for circulation, and the depth allowed for an imperceptible visual transition to the active and insulated louvers.

Another inspired example of what can be achieved by customization of louvers is the air traffic control tower at San Francisco International Airport. The owner wanted something unique—a form that did not resemble the typical lollipop-shaped tower that one finds at many major airports around the world.

Completed in 2015, the $80-million, 221-foot-tall air-traffic control tower replaced the existing tower atop Terminal 2 when it opened in 2016. The 5,652-square-foot structure was the tallest vertical self-centering post-tension concrete structure in the United States when it opened. The building ascends in a graceful arc, topped by a cab that is offset from the central column. A ribbon of glass runs the vertical length of the tower, reflecting sunlight during the day and illuminated by interior lighting at night.

The louver manufacturer’s ability to form special shapes and configurations was essential on this project. Using this capability, designers devised a spiral form resembling the double helix of DNA. The louver manufacturer came up with a unique compound curving concept providing the tower with a distinctive look. Complementing the curving louvers, the west face of the tower features an LED backlit glass element resembling a waterfall that reaches 147 feet in the air.

With the appearance of a trumpet standing on its end, the building curves inward at the middle and then flares out again at the top. And then on the outside, the skin is made up of metal panels and louvers that spiral up the outside of the building in a complex geometry. Essentially, the challenge for the designers and manufacturer was figuring out a way to take a louver that has a rigid, fixed profile and make it move up the building like a flexible element. The result is something that is extremely unique and fulfills the client's desire for a design that had never been done.

Function and Design

Photo courtesy of Lester Ali Photographer

The UConn Science 1 Research Center building presented a multitude of challenges for architect Peter Viera of Payette. Louvers were used to successfully allow for the required ventilation of a research facility while also integrating into the desired aesthetic.

Some projects present a multitude of challenges for the architect when ventilation requirements and aesthetic goals seemingly collide. Such was the case for Peter Viera, FAIA, LEEP AP, Principal-in-Charge of Payette, when tasked with designing a new research facility for the University of Connecticut.

Located in Storrs, Connecticut, the University of Connecticut, UConn, is home to more than 2,000 active researchers who collaborate across multiple disciplines. To further support the faculty and students, a new Northwest Science Quad science district was established on a 22-acre development that transformed a hillside parking lot into a high-performance landscape of green infrastructure. The centerpiece of the expansion was the Science 1 Research Center, a three-story, high-intensity academic research building dedicated to the interdisciplinary fields of material science and engineering.

To incorporate the design of the building comfortably into the lush green space, Viera faced several design challenges.

“Science 1 is a large research building with a significant amount of opaque wall surface area, about 80 percent. The building is located on a large site and was the first building on a new science quad and we wanted to make the building feel smaller and more human-scaled," said Viera. To visually “scale the building down” Viera devised a facade/skin strategy to change the visual perspective so that students and visitors would not be as aware of how large the structure is.

“Part of this strategy lies in the use of an irregular pattern of large-scale ultra-high performance concrete panels that, while recalling the ashlar pattern of a stone wall, are actually much larger than any real stone wall. Another part of the strategy is extending the pattern into the divisions of windows, so that the skin looks "uniform" irrespective of what it is made of.”

A third strategy Viera employed was to keep everything on the facade very taut, with almost no visible depth. While these design choices worked well to offset the massive size of the building, they did not necessarily complement the ventilation requirements of the research facility.

“Of course, being a science research building, it had a very large louver requirement. The massing strategy didn't give us much leeway to hide the louvers because in our design the mechanical penthouse is pushed to the front of the building. So, it was critical that the "one skin" concept could be applied to the louver areas as well,” said Viera.

The solution was to connect with a louver manufacturer with a product that could allow for customization and a keen eye for aesthetic, as well as performance detail.

“We were amazed at how well the louvers were able to integrate with all of the design strategies we had planned. The louvers were panelized to look exactly like the ultra-high-performance concrete (UHPC) skin; it maintains joints that are identical to the concrete; and it is taut, with a customized color that is a perfect match for the other facade components. All without sacrificing any performance!”

Louvers and Curtain wall Systems

Photo courtesy of Lester Ali Photographer

99 Hudson, designed by Perkins Eastman Architects of New York City. Standing 79 stories tall, the tallest building in New Jersey is clad in sleek glass and limestone and incorporates storm-resistant louvers with custom border frames (left).

The Abraham Joshua Heschel School in New York City was designed by Gruzen Samton. The nine-story building features storm-resistant, vertical continuous line louvers on the first and top floors (right).

Today louvers can do much more than optimize energy efficiency, indoor comfort, and help air ventilation. They can play an important role in a building’s overall architectural aesthetic and might even take top billing.

One example of how louvers can play a significant role in a curtain wall system is 99 Hudson by Perkins Eastman Architects of New York. Standing 79 stories tall, the tallest building in New Jersey is clad in sleek glass and limestone and incorporates storm-resistant louvers with custom border frames. Cut outs accommodate pipe penetrations and notching to fit over the curtain wall mullions. On the ground level, storefronts feature oversized windows, accent metal frames, and louvers painted in multiple custom colors. Additional louvers accent the facade on the first few curtain wall floors, roughly 60 percent of the way up the tower and at the penthouse level.

Another project example is the Abraham Joshua Heschel School in New York City. Designed by Gruzen Samton, the nine-story building features storm-resistant, vertical continuous line louvers on the first and top floors to meet performance and aesthetic requirements. The supplier customized the louver frames to seamlessly integrate into the building’s high-performance curtain wall system.

CONCLUSION

Louvers can play an important role in commercial construction. As shown in the case studies, incorporating louvers is a simple but effective way to architecturally break up the mass and scale of a building as well as to create exterior design interest. With skillful design intent and the assistance of a good manufacturer, a louver installation can elevate a project's overall design.

Fortunately, architects, designers, and developers also reap the additional benefits that louvers provide. Specified correctly, they block rain and severe weather and promote energy efficiency.

The evolution of louvers means architects and designs can do more with a versatile system that can adapt to many situations and needs and look good while doing it.

Andrew A. Hunt is Vice President of Confluence Communications and utilizes over twenty years professional writing experience in residential and commercial building science to produce marketing, training, educational and multi-media material. www.confluencec.com