Let the Sun Shine In!

November 1, 2021

Save money, energy and improve worker productivity

Sustainable practices are not only good for the planet, they are generally safer, healthier and save money. One practice, daylighting, is the use of natural light for interior illumination instead of electric lighting. Before electricity became available, daylight was the primary source for lighting spaces and task lighting. Take the Pantheon for example. Completed back in 126 AD, the ancient Romans used a giant circular oculus (27 feet in diameter!) to fill the interior space with light.

Over time, architects employed new technology to use sunlight for interior lighting: glass skylights and large expanses of windows were used to bring light into the built environment before electricity was widely available.

 

Rome’s Pantheon

 

Industrial interior of an old factory building

 

When working with these older buildings, WDM has the goal of preserving as much of their historic character as possible. As an example, WDM was retained to convert old brick factories along the railroad tracks into a new campus for healthcare students at WSU Old Town. WDM and WSU both found it important to preserve as much natural light as possible. So public spaces and corridors were purposefully located under skylights. In some cases, the architect created ledges to direct the light into the interior of the school.

 

WSU’s Old Town renovation from historic factory to classrooms  preserved daylighting from clerestory windows

 

Modern Trends in Daylighting

Beyond glass skylights and windows, Architects use a variety of materials to control the quantity and quality of light entering their designs. Consider the Kimbell Art Museum in Fort Worth, Texas. Designed by famed architect Louis Kahn and opened in 1972, the building uses light scoops, or as the museum puts it, “a cycloid vault with ‘narrow slits to the sky.’” This design prevents direct sunlight from damaging the art, but allows visitors to still experience the art through ever-changing natural light. Kahn said, “No space… is a space unless it has natural light.”

 

Kimbell Art Museum interior

 

Image Credit Priji Balakrishnan

 

Kimbell Art Museum interior

 

Botanica’s Carousel Pavilion utilizes skylights, glass walls and doors to make maximum use of daylighting. WDM used high-performance glass and added a ceramic fritted pattern to cut down on solar gain. The large amount of glazing also allows guests approaching the building to see the carousel shining like a jewel in a glass case.

 

Botanica’s Carousel Pavilion makes maximum

 

WDM’s design of Murfin Animal Care facility in Wichita, Kansas, employs daylighting with both skylights and clerestory windows. These skylights use high-performance, insulating, structural sandwich panels that admit a diffuse light that is nearly indistinguishable from electric fixtures.

Daylighting by clerestory windows and skylights

 

At Murfin Animal Care facility, skylights in the center of the room are as bright as fixtures along the sides

 

Daylighting by clerestory windows and skylights

 

As building technologies have advanced, so has our ability to introduce natural light into spaces in innovative ways. For instance, light reflectors placed on the exterior of a building can redirect sunlight into the building. Light shelves work similarly; these horizontal reflective pieces bounce light onto the ceiling, which diffuses light onto work surfaces and makes the room feel brighter. These shelves can usually be designed as part of the window framing or incorporated as decorative elements on the building’s exterior.

 

 

A daylighting technology that is gaining popularity is called “tubular skylights,” “light tubes,” “sun pipes,” “sun tunnels” and even “light tunnels.” One 10-inch tube can provide the brightness equivalent to three 100-watt bulbs.  The apparatus that sits on the roof is like a prism that collects light from any angle and direction, magnifies it and directs it down a tube that is coated with highly reflective materials. The rooftop footprint is smaller than a traditional skylight.  Solar tubes filter out harmful UV and with a longer tube, it can be used deep into interior spaces.

 

WSU’s John Bardo Center also uses Solar Tube technology to increase the light in a large interior space

 

Daylighting can help to save endangered animals

WDM used light tubes in the Conservation Center for breeding endangered animals at the Phoenix Zoo. These animals use the diurnal cycle as a cue to time their reproduction, so daylighting is critical to their breeding success. “Light experienced during a critical window of the circadian (daily) rhythm can influence reproductive physiology,” according to scientific studies. Sun tubes were also used in the Orangutan Habitat at the Columbus Zoo.

Solar tubes for conservation. Photo credit: Dave Seibert

 

Almost any building can make use of daylighting to improve its sustainability. WDM’s office uses a couple of methods to take advantage of available daylight and reduce energy usage. Located in Wichita’s Old Town district, the WDM office once housed the Dye Chili Factory. Renovations focused on both retaining the historic structural elements and updating with sustainable technologies. To control when electric lighting is used, we use occupancy/motion sensors and daylight sensors which switch off electric lighting when natural daylight is abundant. Additionally, our open office floorplan allows light to penetrate deeply into the floorplate. The exposed concrete ceiling is also painted white in order to reflect as much light as possible down to the work surfaces.

 

WDM’s own building in downtown Wichita uses occupancy sensors and daylight sensors and is designed with no enclosed offices to maximize natural light.

 

So there’s the tech, but what’s the bottom line? Not only can these methods reduce electric costs, they can also reduce HVAC costs, since electric lighting generates a lot of heat. Daylighting technology takes heating, cooling and glare into consideration. Most buildings can expect an overall energy savings of 15 to 40 percent. Natural lighting also adds to the well-being, productivity and overall satisfaction of those inside the building by connecting them to the natural cycle of the sun.

Bottom line: Daylighting is not only good for the planet, it can save 15-40% in building operating costs, and employees perform 10-25% better.

A study by the Heschong Mahone Group, Inc. found, when provided with a better indoor work environment including daylight, an outdoor view and better ventilation conditions, office workers perform 10 to 25 percent better on tests of mental function and memory recall. They also were less likely to report negative health symptoms. Not only that, call center workers process calls 6 to 12 percent faster; and students perform 20 percent quicker on math tests and 26 percent quicker on reading tests.

Here’s another reason why this is all so cool: daylighting is 100% renewable and efficient and it reduces the demand for electricity, which accounts for up to 40 percent of carbon emissions generated by buildings. Daylighting can also contribute significantly to meeting energy efficiency requirements in building codes, LEED and CHPS programs and is consistent with the U.S. Green Building Council energy reduction initiatives.

At WDM, we’re constantly optimizing the design of our buildings in ways that benefit our clients.

 

 

Thanks to these great sources:

https://www.wbdg.org/resources/daylighting.php

http://www.daylighting.com/whydaylighting.php

http://www.facilitiesnet.com/lighting/article/How-Daylighting-Works–10445?source=part