Prior to the invention of the lightbulb, buildings were lit only by the sun, which limited their depth to the distance daylight could penetrate the space through windows. Once electric lighting and mechanical ventilation were introduced, however, deeper floor plates emerged that pushed occupants further into the building and away from the outdoors, which resulted in negative health impacts, according to the American Institute of Architects (AIA).
“Those without access to daylight and views have been shown to be less productive and less creative, and to take more sick days—at a significant expense to their communities and the companies for which they work,” the AIA reported in its Framework for Design Excellence series.
Today, views to the outdoors and other daylighting strategies in buildings are becoming commonplace, especially as more companies focus on the health and wellness of their employees and visitors. But in existing facilities where ample daylight and views to nature are somewhat limited, retrofits to improve daylighting can be costly.
Fortunately, by implementing the right daylight harvesting and LED color tuning strategies, design professionals and facility executives can reap the benefits of proper lighting in whatever type of building they’re working with.
Daylighting vs. Daylight Harvesting: What’s the Difference?
Aren’t daylighting and daylight harvesting the same thing? Not exactly.
Daylighting is a term that describes energy management techniques that reduce overhead lighting by utilizing the ambient (natural and artificial) light present in a space, dimming or switching lighting off when sufficient lighting is present or when the space is unoccupied, or utilizing zones to stagger the dimming and switching of lighting loads depending on their distance from ambient light sources, such as windows or skylights.
It requires architectural design elements to strategically incorporate natural light into the structure’s aesthetics and functionality. This is a process that typically happens during the pre-construction and construction phase of a new project and is required by codes and standards including IECC, ASHRAE 90.1 and 2016 Title 24, Part 6.
In most applications, daylighting can result in a 35-60% energy reduction in buildings, saving money and resources. It also helps to create a more pleasant, properly illuminated space. As noted earlier, while existing buildings can be remodeled to incorporate more daylighting, these renovations can be costly.
[Related: 4 Lighting Strategies for Energy Efficiency]
Daylight harvesting, on the other hand, employs lighting controls to utilize daylight such as photocells, occupancy sensors and centralized or distributed systems, which can be planned during the design and planning of a building, or flexibly retrofitted later.
Common harvesting methods include dimming or switching lights when enough ambient light is present or installing occupancy sensors that keep lights off in rooms that are vacant and turning them on when occupants enter the space.
Daylighting zones can also be created within a building that stagger the dimming and switching of lighting loads depending on a zone’s distance from ambient light sources, such as windows or skylights, which requires integrated photocells to sense lighting in each zone. Harvesting can also be achieved through advanced scheduling based on time-of-day and sunrise/sunset clocks to ensure exterior lighting is not on during daylight hours (also known as Time Clock Control).
The Importance of Color Tuning in Interiors
When it comes to creating an optimal visual environment—regardless of daylighting levels—color tuning plays a vital role in the process. Color tuning refers to controlling colors emitted by a room’s lighting, which can be manipulated and refined to produce a specific, predetermined color using LED lighting products.
Utilizing proper color tuning techniques offers a variety of benefits to facilities and occupants, including improved employee productivity and morale; superior ambiance and increased guest satisfaction; improved occupant well-being; optimal display of products in retail settings, leading to increased sales; and better learning environments and attendance in education applications. Here’s how:
Color tuning can help mimic natural colors throughout the workday in both work spaces that receive natural lighting and those that are fully enclosed. This is significant because it can help keep occupants aligned with their natural circadian rhythms, which has been shown to improve employee productivity and morale. It can also facilitate social interaction with naturally rendered skin tones and faces, creating a more appealing and constructive work environment. Individual customization for private offices, conference rooms and other specialty areas is easily achieved with color tuning.
Studies have shown that good lighting has a positive impact on student attendance and performance. Proper color tuning can help create better learning environments with LED lighting that provides pleasant, natural illumination whether the classroom receives natural lighting or not. Classrooms, study rooms, dorm rooms and other specialty spaces can be individually customized for optimal levels.
First impressions make a big impact on guests, so designers need to create inviting and appealing spaces. One way to do that is to precisely design indoor lighting to match furnishing colors and materials, which can easily be adjusted later for furniture changes and building updates. They can enhance lobbies and other atrium spaces utilizing daylight harvesting by more accurately measuring the hue of natural light. Color tuning also allows hotel guests to control their individual room’s color temperature and settings, from general scenes to precise preferred colors.
Retailers want to showcase products in the best possible light—and proper color tuning ensures does just that. In fact, the optimal display and rendering of products—clothing and accessories appear more vibrant, truer and ultimately more appealing—can lead to increased sales. Further, retailers can utilize customization to reflect current product lines, seasons, merchandising schemes and more in display areas for dynamic and precisely designed stores that can be replicated across infinite numbers of locations for consistency.
Hospitals and doctors’ offices can increase stress levels in adults and children alike. Designers can help combat this by utilizing color tuning to nurture a welcoming, home-like atmosphere to put patients at ease and make all visitors comfortable. Proper light levels and colors can also render skin tones more accurately to help medical staff detect illnesses such as jaundice, rashes, infections, fevers and other conditions with visual cues. Bringing natural coloring of the sunrise/sunset light cycle to the space can further enhance the healing process, increase wakefulness throughout the day and promote better sleep at night.
Warehouses and distribution centers need consistent, bright light for employees to safely do their jobs. Replacing outdated lighting with energy efficient LED luminaires that can be color tuned to the specific conditions of the environment means that the aisles are well lit and glare free, allowing foot and equipment traffic to travel safely throughout the warehouse. Product labels are highly visible, and flicker free lighting makes it easy to spot moving machinery and prevent accidents. These fixtures also give off less heat, have longer life spans, and require significantly less maintenance than metal halides or sodium lamps.
Techniques for Color Tuning Perfection
As demonstrated in the previous section, the ability to tune light fixtures to desired temperatures has numerous benefits in a variety of applications. But color tuning LEDs properly includes a variety of considerations and scenarios, including:
Dim to Warm—This scenario refers to adding red or amber lights to an LED fixture, with a second driver that exclusively controls these warm lights. When the fixture dims to a low Kelvin (K) level, the red lighting is raised to create a warmer, more even and more pleasant dimmed lighting effect. Also referred to as the “sunrise effect,” as it mimics the warm, pleasing natural lighting of a sunrise- or sunset-illuminated space.
Color Tuning/Tunable White—Typically, a tunable white lighting scenario contains two sets of controllable LEDs, one warm and one cool. The two lighting sets can be raised and lowered in any combination to produce dimmed or full-on lighting that conforms to the desired color temperature. Lighting combinations can also be preset with control systems as scenes, providing different lighting temperatures for a variety of scenarios, times of day, etc.
Color Changing/Full Color Tuning—This method of color tuning provides the greatest flexibility and customization, but is also most complicated approach. In this scenario, three or more LED primary colors can be individually controlled and varied to create desired hues—pure white, white/tinted dimmed, or a saturation of any other color.
Circadian Rhythm Color Tuning—This approach includes the full range of dimming and daylighting capabilities to adjust for natural light present in the space. Designers and facility executives can assign color tuning settings based on schedules and time clock events, with the ability to switch and customize scenes manually in the easy-to-use, intuitive touchscreen interfaces. Circadian rhythm simulation can continuously run in the background without any scheduled events. This scenario provides full color tuning capabilities for DMX (digital multiplex) and/or 0-10V LED fixture lighting, and results in positive health benefits for occupants as noted previously.
When it comes to implementing effective lighting design strategies and the incredible flexibility and many benefits of color tunable LED lighting systems, the question isn’t should you consider them—it’s why wouldn’t you?
This article was produced in partnership with Leviton. To learn more, visit leviton.com.