The Role of Lighting in Outdoor Spaces to Address Energy Efficiency, Lighting Quality and Light Pollution

The Role of Lighting in Outdoor Spaces to Address Energy Efficiency, Lighting Quality and Light Pollution

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Sponsored By: Acuity Brands Lighting

Eric Gibson, Director – Outdoor Products, Acuity Brands Lighting, recently sat down for a Q&A to discuss the role of lighting in outdoor spaces, achieving lighting quality and efficiency, and how today’s outdoor lighting products reduce lighting pollution.

In 2021, outdoor and green spaces will continue to be developed as standalone projects and as a part of new build construction and renovation projects. Eric foresees a renewed emphasis on occupant experiences, as many visitors, occupants and residents seek opportunities to connect in exterior spaces. Designing with outdoor lighting products will focus on solutions that are functional, offer visual comfort and illuminate spaces for safe use and, in doing so, create lighting solutions that also maximize energy efficiency and reduce light pollution.

  1. Can you please speak generally about what LEDs offer for outdoor lighting today and the benefits related to light quality and efficiency?

The Role of Lighting in Outdoor Spaces to Address Energy Efficiency, Lighting Quality and Light Pollution Eric Gibson: Over the last decade, LEDs have evolved from being an emerging technology to becoming the dominant source for new outdoor lighting products. The benefits of this technology are greater efficacy, longer product life, improved optical control, light quality, and greater dimming capabilities.

Newly designed outdoor LED lighting products typically provide energy reductions of 70% over the products replaced, making them attractive solutions both financially and environmentally. Not only are they significantly more efficient, but their smaller size makes them more controllable, allowing the use of advanced optical designs to provide superior illumination where it is needed while minimizing light trespass outside the target area.

Traditional HID luminaires resulted in over-lighting of areas directly underneath the luminaire and had significant stray light behind the pole. With the optical control of LEDs, this stray light can be minimized while providing uniform lighting that not only requires less light output to achieve the desired results, but also improves the visual acuity of the occupants. Since LEDs are solid-state devices, they can be easily dimmed using advanced controls, enabling even more energy savings during periods of non-occupancy.

Lastly, the quality of LED light is far superior to that of metal halide and HID lighting, providing better CRI (color rendition), more accurate CCT (correlated color temperature) and a fuller spectrum instead of the spikey spectral power distribution of HID.

  1. If not used with guidance, LEDs can increase light pollution due to the blue light emitted, is that a concern for outdoor environments? How do outdoor lighting products address this problem?

Eric: “Light pollution” is a broad term with many facets. Well-designed LED lighting greatly reduces light pollution in that sky glow reduction can be significantly reduced by designing luminaires that use less light to achieve the desired illumination, and by incorporating advance controls to dim the luminaires during the late-night hours when there is low occupancy. LEDs can also greatly reduce light trespass, another form of light pollution. So, the result is that LED lighting solutions are more effective at targeting light to the areas where its needed, instead of casting stray light in other areas. We design our products so that less light is reflected upwards, reducing sky glow and minimizing stray light that can come from light trespass or misdirected uplighting.

Recently, there has been research about the potential health effects of blue light from electronic devices and outdoor lighting during nighttime periods. The good news is that outdoor LED lighting technology has evolved, and highly efficient LEDs are now available with warmer CCTs that have significantly less blue light, providing customers with a choice. Acuity Brands offers lower CCT (3000K) light sources on all our best-selling outdoor product families and these solutions also meet the recommendations of the International Dark Skies Alliance.

Blue light emissions can be a problem for both observatories and wildlife. Blue light is a concern in areas near astronomic observatories as sky-glow with blue-wavelength light can obscure the view. Similarly, blue light in sea turtle nesting areas can confuse hatchlings and prevent them from heading into the ocean after hatching. At Acuity Brands, we have special applications applied to LED lighting to provide a solution to these difficult problems such as luminaires with amber-colored LEDs instead of the cool blue light. In fact, we have luminaires available in a monochromatic amber tone that are approved by the Florida Wildlife Commission specifically for use in sea-turtle protected areas.

  1. How can the proper products reduce light pollution and are there products that specifically offer lower stray lighting? Can you please describe?

Eric: Most of our area lighting luminaires, for example, do not have any uplight, as indicated in their B-U-G ratings. And while our standard products are optimized to reduce light trespass, we also provide specialty products that specifically address backlight. To address backlight, patented optical system sharply cut off light behind the luminaires, allowing customers to help meet stringent light trespass requirements, such as LEED and California Title 24.

Our Lithonia Lighting® outdoor products reduce light pollution through a series of performance features:

  • offering superior optical control, allowing less light to be used while achieving superior visual acuity;
  • using that same optical control to minimize light going outside the target area (light trespass);
  • using advance controls such as our wireless nLight® AIR platform to allow the luminaires to be trimmed to meet the specific needs of the site and dimmed during periods of non-occupancy; and
  • providing low CCT (3000K) options for blue light reduction if required.
  1. What factors should lighting engineers and contractors consider to ensure the proper use of LED lighting outdoors?

Eric: As in all cases, picking the right tool for the job is critical to success. Lighting engineers and electrical contractors should specify outdoor products that offer superior uniformity with minimal trespass and low power density, which can be achieved by selecting luminaires with exceptional photometric control. Energy savings can be further increased by over 50% by selecting a luminaire with wireless embedded controls, as these cost-effective controls allow the luminaires to be trimmed to meet the specific needs of the site and dimmed during the extended periods of non-occupancy which is typical of outdoor lighting.

Our overall goal at Acuity Brands is to create cost-effective lighting solutions that meet the needs of the occupants while complying with local and national codes. We aim to take the guess work out of choosing the right lighting for the job by providing clear information on the application and lighting specifications for each product.

For the past 75 years, Lithonia Lighting has been providing the Best Value in Lighting™ by offering our customers products known for their quality, reliability, and solid performance.  To learn more about Lithonia Lighting outdoor lighting solutions, visit lithonia.acuitybrands.com.

Contributor(s)

Eric Gibson

Eric Gibson

Eric Gibson is the Director for Commercial Outdoor Products at Acuity Brands Lighting. Eric received his Bachelor of Science degree in Illumination Engineering at the University of Colorado and his Executive M.B.A. at Mercer University in Atlanta. Eric has been in the... More info »