This report examines the issue of sustainable lighting in buildings. Sustainable lighting is of increasing interest in concert with the initiative to implement ecologically friendly solutions to familiar problems, particularly those associated with the provision and expenditure of energy. The use of sustainable lighting can help build smarter buildings and cities by reducing the amount of light to the amount needed for the place and the user. Lighting is extremely important when it comes to human use and task lighting. It affects circadian rhythm in users, productivity in a workspace, and can create better retail experiences.
Lighting has been singled out as a key consideration for green design because it accounts for one-seventh of the energy use of the typical residence and nearly one-quarter of the energy use in a commercial structure. Concerted research and development efforts are therefore underway to minimize the effect of lighting upon the energy footprint of both residential and commercial buildings such large-scale structures as office buildings and factories. The most promising solution paths involve more efficient use of daylight; systems that “transport” sunlight from place to place; a variety of energy-efficient light bulbs, and lighting control systems
Daylight is the most abundant source of light available. However, there are several difficulties associated with excessive reliance upon daylight. First, it is not available at night. Second, careful architectural design is necessary because excessive use of daylight can result in widely fluctuant indoor temperatures in living and working spaces as well as intolerable levels of glare. Thus, windows and skylights must be
situated efficiently, and atriums and translucent panels must be provided in a manner that is harmonious with the overall architecture of the structure. Further, mirrors and reflective surfaces must be incorporated so that light is relatively evenly reflected throughout the occupied spaces (Gray, 2018).
Sunlight transportation is a newly emergent technology that is of key interest. Not only are the health benefits of natural sunlight well understood, but also workers in major cities have actually won lawsuits over being denied sunlight by injudicious placement of skyscrapers in downtown areas (Grabar, 2014). The essential idea is that sunlight is collected by roof panels and transported into building interiors via fiber optic cables. Commercially available cabling is able to transport sunlight over a distance of fifty feet, or approximately five stories, without perceptible degradation. Systems that pipe sunlight in this manner can be used in combination with solar panels that power interior artificial lighting in order to provide energy-efficient lighting around the clock (Gray, 2018).
Lighting control systems are the most efficient way to save energy and provide light at the right place and the right time. Control systems can be programmed to solve issues with residential and commercial buildings. In an office setting, lighting control systems can increase productivity by creating the most optimal work conditions by ensuring that the lighting is not too dim or too intense. It can also detect the amount of natural light the space is getting and adjust it to the user’s task. Lighting control can produce the right amount of light by diming the intensity of the light output. Zoning of luminaires to control where light is needed and automatically reduce the lighting when the space is unoccupied. It also allows remote programming and control.
Since light bulbs are still used in most interior lighting systems, considerable effort has been devoted to making them more energy-efficient. The standard incandescent bulbs, which works by bringing a tungsten filament to extreme heat so that it glows, only convert ten percent of their input energy to visible light. While halogen lights burn more brightly while consuming less electricity, they are still remarkably inefficient. Scientists have developed two classes of bulb that are more efficient, the compact fluorescent light, or CFL, and the light-emitting diode, or LED (Gray, 2018).
Compact fluorescent lights are smaller versions of standard fluorescent lights, constructed of glass tubes that are coated with phosphor and filled with gases. The gases give off ultraviolet light when electrically excited, and that ultraviolet light excites the phosphor coating to emanate visible light. CFLs are capable of producing the same amount of light as incandescent bulbs but are four times more energy-efficient and last up to ten times longer. Moreover, the greenhouse gas, carbon dioxide, produced by standard incandescent bulbs because of their heat is reduced by seventy percent in the CFL. Another drawback of CFLs is that they contain the toxic metal, mercury, which must be disposed of per strict protocols in order to avoid environmental damage (Gray, 2018).
Light-emitting diodes are small, solid structures rather than fragile, hollow glass assemblies. They are made of semiconductor materials that glow when electrically excited. LEDs are capable of lasting more than one hundred times longer than incandescent bulbs. Moreover, they produce a minimum amount of attendant heat. One difficulty with LEDs is that they are principally useful only for pinpoint, high-intensity lighting, being considerably less efficient at providing lighting that is more diffuse over larger areas (Gray, 2018).
One of the projects I specifically studied is the National Renewable Energy Laboratory (NREL) located in Golden, Colorado. It is one of the sustainable and net zero buildings that incorporated state of the art energy efficiency and renewable energy technologies. It earned a platinum certification in Leadership in Energy and Environmental Design (LEED). NREL designed the space to have about 80% of regularly occupied spaces have daylighting, LED lights with smart lighting control systems and radiant heating and cooling.
Therefore, being aware on how lighting affects buildings in terms of energy and sustainability is crucial for the efficiency of the building. The overall design needs to take into account sustainability and efficiency without compromising the needs of the users health and productivity.
Grabar, H. (2014, April 20). Welcome to the permanent dusk: Sunlight in cities is an endangered species. Salon. Retrieved from https://www.salon.com/2014/04/20/welcome_to_the_permanent_dusk_sunlight_i n_cities_is_an_endangered_species/.
Gray, J. (2018, December 19). Sustainable lighting. Sustainable Build. Retrieved from http://www.sustainablebuild.co.uk/sustainablelighting.html.
How energy-efficient light bulbs compare with traditional incandescents. (Updated). U. S. Department of Energy. Retrieved from https://www.energy.gov/energysaver/save-electricity-and-fuel/lighting-choices-save-you-money/how-energy-efficient-light.
Montes de Oca, S. (2017, February 8). What is LEED and how does it relate to lighting?
Super Bright LEDs. Retrieved from https://www.superbrightleds.com/blog/leed-relate-lighting/3945/.