Technology Fact Sheet EFFICIENT LIGHTING STRATEGIES EFFICIENT LIGHTING STRATEGIES For more information, contact: LIGHTING PRINCIPLES AND TERMS temperatures (3600 to 5500 K) are what we EFFICIENT LIGHTING INITIAL DESIGN RECOMMENDATIONS • Also consider L IGHT QUANTITY Energy Efficiency and consider cool and lower color temperatures Home designers and builders can reduce lighting energy use - Light wall colors to minimize the need for artificial lighting. Renewable Energy The quantity of light emitted by lamps is (2700 to 3000 K) are considered warm. Cool STRATEGIES by selecting light fixtures and sources that use energy more Clearinghouse (EREC) measured in lumens. By way of reference, a ® light is preferred for visual tasks because it efficiently, and by installing controls to reduce the amount of - Energy Star lighting fixtures. 1-800-DOE-3732 100-watt incandescent lamp emits about 1750 produces higher contrast than warm light. Wise design choices can meet lighting needs time lights are on. - Occupancy detector controls. www.eren.doe.gov lumens. While the quantity of light produced Warm light is preferred for living spaces and save energy INDOORS OUTDOORS Or visit the Building by a lamp is measured in lumens, the purpose because it is more flattering to skin tones Technologies Program • Maximize the use of daylighting. • Security and utility lighting does not need to be bright to be of all lighting is to produce illumination (i.e., to and clothing. A color temperature of 2700 to Web site at INTRODUCTION Recent technological improvements allow provide light on a surface). The intensity of • Install fluorescent light fixtures for all ceiling- and wall- effective. www.buildings.gov 3600 K is generally recommended for most Convenient and effective artificial lighting is homeowners to substantially reduce the illumination is measured in footcandles. A mounted fixtures that will be on for more than 2 hours each • Use fluorescent, HID, or low-pressure sodium lights unless indoor general and task lighting applications. one of the important advances of the 20th energy they use for lighting without loss of footcandle is the illumination produced by one day. These often include the fixtures in the kitchen and living incandescent lights are automatically controlled to be on for Written and prepared for the • Color rendition refers to how colors appear Buildings for century. Artificial lighting allows us to work amenity. lumen distributed over a 1-square-foot area. room, and sometimes those in bathrooms, halls, bedrooms, just a few minutes each day. U.S. Department of Energy by: when illuminated by a light source and is the 21st Century and play inside and outside our homes For most home and office work, 30 to 50 independent of the time of day, and also often BENEFITS OF ADVANCED LIGHTING and other higher-demand locations. Install dedicated compact • Consider incandescent flood lights with combined Southface Energy Institute generally considered to be a more important footcandles of illumination is sufficient. For Buildings that are more Artificial lighting consumes almost 15 percent fluorescent fixtures, rather than CFLs in incandescent fixtures, 404-872-3549 lighting quality than color temperature. Most serves aesthetic purposes. Artificial lighting is photosensors and motion sensors in the place of other energy efficient, comfortable, www.southface.org detailed work, 200 footcandles of illumination generally employed for three types of uses: of household electricity. The traditional so that fluorescent bulbs continue to be used for the life of security lighting options. objects are not a single color, but a or more allows more accuracy and less and affordable…that’s the the house. incandescent bulb with screw base currently U.S. Department of Energy’s combination of many colors. Light sources goal of DOE’s Building Ambient lighting—Provides general • Make sure outdoor light fixtures have reflectors, deflectors, or eyestrain. For simply finding one’s way around provides most household illumination. Use of • Encourage occupants to use CFLs in portable lighting fixtures Oak Ridge National that are deficient in certain colors may Technologies Program. illumination indoors for daily activities and covers to make more efficient use of the light source and help Laboratory at night, 5 to 20 footcandles may be sufficient. new lighting technologies can reduce lighting that are operated for more than 2 hours a day. change the apparent color of an object. The To accelerate the development outdoors for safety and security. reduce light pollution. Buildings Technology Center energy use in homes by 50 to 75 percent. E FFICACY Color Rendition Index (CRI) is a 1 to 100 and wide application of energy Task lighting—Facilitates particular tasks that • If recessed lights are used in a ceiling with an unconditioned 865-574-5206 Advances in lighting controls offer further • In most applications, use One of the means to reduce lighting energy scale that measures a light source’s ability to efficiency measures, the space above it, use only Underwriters Laboratory (UL) www.ornl.gov/btc require more light than is needed for general - Photosensors to turn off lights during daylight hours. consumption is to use light sources that render colors the same way sunlight does. Building Technologies Program: energy savings by reducing the amount of approved fixtures that are airtight, are IC (insulation contact) U.S. Department of Energy’s illumination, such as under-counter lights in produce more light from little electricity. The The top value of the CRI scale (100) is based time lights are on but not serving a useful rated, and meet ASTM E283 requirements. - Motion detectors to activate security or utility lighting National Renewable Energy • Conducts R&D on technologies kitchens, table lamps, or bathroom mirror lights. ratio of light produced to energy consumed is purpose. Advanced lighting controls also offer when needed. Laboratory on illumination by a 100-watt incandescent and concepts for energy effi- Accent lighting—Draws attention to special a new amenity—lights that come on 303-275-3000 called efficacy. Efficacy is measured as the light bulb. A light source with a CRI of 80 or ciency, working closely with - Timers and other controls to turn decorative lighting on features or enhances the aesthetic qualities of www.nrel.gov/buildings number of lumens produced divided by the higher is considered acceptable for most the building industry and with automatically when they are needed. and off. an indoor or outdoor environment. rate of electricity consumption (lumens indoor residential applications. manufacturers of materials, per watt). equipment, and appliances • Glare refers to excessive brightness from a • Promotes energy/money DEDICATED COMPACT FLUORESCENT FIXTURES L IGHT QUALITY direct light source that makes it difficult to INDOOR/OUTDOOR LIGHTING TYPES ○○○○○○○○○○○○○○○ saving opportunities to both Installing compact fluorescent fixtures that accept only Three concepts are important to understand see what one wishes to see. A bright object There are varied lighting technologies for all lighting situations. Consideration should be given builders and buyers of homes CFLs ensures lifelong energy-saving benefits. Many new lighting quality: in front of a dark background usually will to energy-efficient lighting choices in fixtures that are on for more than 2 hours a day. and commercial buildings CFL fixtures offer a dimmable feature and perform much like • Color temperature refers to the color of the cause glare. Bright lights reflecting off a • Works with state and local Utility lighting incandescent fixtures. light source. By convention, yellow-red television or computer screen or even a regulatory groups to improve colors (like the flames of a fire) are printed page produce glare. Intense light building codes, appliance Pole-mounted considered warm, and blue-green colors (like sources such as bright incandescent lamps lighting standards, and guidelines for light from an overcast sky) are considered are likely to produce more direct glare than efficient energy use cool. Color temperature is measured in Kelvin large fluorescent lamps. However, glare is Flood ○○○○○○○○○○ lighting Insulation Contact (IC) rated recessed NOTICE: Neither the United (K) temperature. Confusingly, higher Kelvin primarily the result of relative placement of fixtures allow complete coverage of States government nor any agency thereof, nor any of their light sources and the objects being viewed. insulation in attic installations. employees, makes any warranty, express or implied, or assumes any legal liability or responsibility Task lighting for the accuracy, completeness, Accent lighting or usefulness of any information, Accent lighting apparatus, product, or process Ambient lighting disclosed. The views and opin- ions of authors expressed herein do not necessarily state or reflect Printed with a renewable-source ink on paper containing at least 50% wastepaper, including 20% postconsumer waste. those of the United States gov- BUILDING TECHNOLOGIES PROGRAM December 2002 DOE/GO-102002-0787 ernment or any agency thereof. OFFICE OF ENERGY EFFICIENCY AND RENEWABLE ENERGY • U.S. DEPARTMENT OF ENERGY EFFICIENT LIGHTING STRATEGIES LIGHTING DESIGN CONCEPTS home but little direct sun during the summer, especially when Fluorescent lamps use 25 to 35 percent of the energy used by EXTERIOR LIGHTING OPTIONS Energy-efficient lighting design focuses on methods and properly shaded. North-facing windows