Soaking Up the Sun

Sunshades and Light Shelves are for More than Just the Building

By Luly Hernandez

While artificial lighting is necessary in some cases, access to windows and daylight is still critical to the well-being of people—and even the environment.

Research has shown that glass and glazing products that stream natural light into a building can provide several benefits for the occupants such as increased productivity and overall improved well-being. As a bonus, high-performance glazing systems can also increase a building’s energy efficiency, making it that much more sustainable.

But windows can sometimes cause occupant discomfort, in particular, increasing solar heat gain and glare. Fortunately, there are ways to enjoy the advantages of natural light while avoiding the disadvantages. Products such as sunshades and light shelves can help address some of those concerns. These products reduce the amount of heat and glare entering a building. A variety of products are available from different manufacturers, all with the same purpose. Historically, however, they haven’t always looked the same.

“The original sunshade was a deciduous tree on the south side of a house because, during the summer, it would have all its leaves and block out a lot of the sun,” says Zac Adams of the Contract Management Division at Southern Aluminum Finishing in Atlanta. The tree didn’t provide shade during the winter, so it allowed for sunlight and some heat to enter a home.

“Think of it [in terms of] comfort and building efficiency,” says Adams. “If you have the sun blaring on your windows all day, it’s just going to heat the building. [Sunshades and light shelves] are a passive way to keep some sun and heat out of the building, so it’s a little more comfortable.”

While sunshades are located outside a structure to provide shade, light shelves are used inside to refract daylight onto the interior ceiling. The strategic placement of light shelves re-directs and deflects sunlight and allows for greater energy efficiency.

“They reduce the need for artificial lighting in buildings…and can reflect light deeper into a space,” says Adams.

One difference between the two is that shading systems on the exterior provide optimal control of solar heat gain while interior devices allow heat to enter the envelope and provide natural light without the glare. The two devices are different but can sometimes work together and increase the benefits for those inside a building.

Sneh Kumar handles product management and marketing for Arconic’s Building and Construction business based in Atlanta. Kumar says there is a lot to consider when designing a building’s façade. This includes both aesthetics and energy efficiency.

Building designers use sunshades to provide shading, improve daylighting and enhance aesthetics, says Nathan Seaman, national sales manager of Architectural Grilles & Sunshades located in Frankfort, Ill. It is important to note that there is more to a sunshade than just what the name implies—they also allow for a broad selection of non-tinted glazing, the ability to utilize more glazing, provide unrestricted views to the exterior and help improve the building’s HVAC performance, he says.

Another difference between the installation process of sunshades and light shelves is ensuring one is prepared to endure natural elements.

“You’re going to be dealing with weatherproofing at the attachment points [of sunshades] to make sure that you’re not getting any water or air coming through, that it’s properly sealed. And you also [need] some form of a thermal barrier so any heat gained from the sun onto the aluminum of the sunshade is not radiated into the building,” Seaman says.

Alternatively, light shelves are found on the interior of the space and don’t face the elements.

Light shelves won’t have to be weather-proofed or sealed and since they’re inside, they aren’t affected by thermal isolation or heat gain, he continued.

“Beyond that, they’re going to attach in a similar fashion with similar brackets and similar hardware… you could have fewer brackets on a light shelf, because you don’t have any wind loading or snow loading. You have fewer engineering requirements on the interior of the space.”

Playing with Light and Shade

There are a number of considerations for those selecting sunshades and light shelves, including the direction of the structure’s façade.

“Starting with the latitude and direction of the façade, you can select between the various types, shapes, and orientations of sunshades,” Seaman says.

“A north-facing building may not need the sunshade because there is not much direct sun on that side,” Kumar adds.

However, there’s more to selecting these devices than just pleasing a certain aesthetic. Building codes play a big part and dictate some important considerations.

“Building energy codes have requirements around how much solar heat gain is allowed, and they also have requirements in terms of the shading of fenestration products, such as windows or curtainwall,” Kumar says. “There are some mandates and code requirements around that, so architects and building designers have to follow those.”

Additionally, installers need to pay attention to pre-assembled sunshade systems, as they not only allow for reduced field labor but also improve building turnover and ensure consistent quality, Seaman says.

When a building is expected to use sunshades and light shelves, meticulous planning is involved. Sun studies are done, figuring out the type of air conditioning and mechanical systems that should be in place, which designs will be the most efficient and so on.

But, issues arise when budgets run tight and last-minute changes are made and all of the meticulous planning isn’t redone.

“They designed it for a certain type of shade device, and then changed it last minute for a [new] budget without redesigning. What’s going to happen, is they’re going to get a system that’s not very effective, whether visually, [with] glare coming in, or functionally, [where they don’t] have a good AC system in place,” Seaman says. The original system is designed according to a shading model that now doesn’t exist due to the last-minute changes.

Other challenges that Seaman has noticed are misconceptions—one being that incorporating these devices in a curtainwall or storefront system is difficult.

“I don’t think that’s actually a challenge at all,” he says. “You can have a properly engineered sunshade system attach to any curtainwall or storefront system without concerns; being that it’s designed and engineered for that specific system.”

The Physical Benefits

There are different presences of light in our daily lives that hinder physical health and aren’t always visible to the naked eye. For example, flicker lighting, which Seaman explains, isn’t just the obvious flickering of a lightbulb.

For example, snapping a picture or capturing a video of a computer screen causes that image to flash in the camera. That’s an example of invisible flicker lighting, Seaman says. And visible or invisible, it impacts the body.

He continues, “[Natural lighting allows for] shifting color temperatures throughout the day—it’ll start cool and then it’s going to warm, and that’s going to help the body’s natural circadian system to align.”

Incorporating sunshades and light shelves also allows for more windows, more glazing and for “more occupants to have a view to the outside, whether it be in an education or business environment,” Seaman says.

Kumar says numerous studies show that having access to outside views and daylighting is highly beneficial in terms of productivity, well-being and learning enhancement.

“You don’t want to create a closed environment where you don’t have access to it. And sun control devices obviously help because you can still have a good view to the exterior and not have unwanted solar heat gain coming inside your building,” he says.

A Bright Future

Effective sunshades allow buildings to earn different certifications for being sustainable and energy-efficient. These programs include LEED, the WELL Building Standard and the Living Building Challenge. Still, there are ways for sunshades to become even more effective.

Instead of just protecting occupants from the sunlight’s glare and harmful rays, these devices can be even more sustainable by generating solar power. Kawneer, which is part of Arconic, has incorporated this technology into its product portfolio with the PowerShade system, with a building integrated photovoltaic (BIPV) shade.

That’s something Seaman has seen, as well. It’s still a premium innovation, but it can improve the way people experience comfort, he says.

There are also opportunities to incorporate automation. “Sunshades [with] photocells are tracking the sun, and their blades are rotating throughout the day, so it’s always an optimal performing system, year-round. Throughout the day, you’re always getting the exact shading that you want,” says Seaman.

He adds this is another opportunity, but the potential and current use is still limited due to the cost of the technology compared to traditional products.

Luly Hernandez is the assistant editor for USGlass. Email her at
lhernandez@glass.com and connect with her on LinkedIn.

To view the laid-in version of this article in our digital edition, CLICK HERE.

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