Follow these strategies to ensure the home's artificial lighting is as practical and energy-efficient as possible.
Develop a lighting plan
A lighting plan should include both the location and the specifications of fixtures and controls on a page of the architectural plans. Decorative, task, focal, and safety lighting should be addressed in the lighting plan and specifications, along with the ambient lighting prescribed in the codes.
Guidance may be found from professional lighting designers, who are often on staff at lighting supply retailers. Typically, these designers are architects or interior designers with a specialty in lighting. Many are fee for service consultants.
To locate a lighting designer in your area contact the
Illuminating Engineering Society of North America or the
International Assoc. of Lighting Designers. Make sure they are aware of the natural lighting in each room as well.
Northwest Energy Alliance provides primers in lighting design based on room use and energy efficiency (click on Lighting Plans).
ENERGY STAR Qualified Fixtures
Specify ENERGY STAR qualified fluorescent fixtures for substantial energy savings. Installing these products for the 5 most used fixtures will save homeowners about $60 per year.
Any objections to the glow cast by fluorescent lamps can be overcome by specifying a lamp with a higher Color Rendering Index (CRI). The CRI scale ranges from 0-100, with natural daylight representing the top of the scale. Newer fluorescent and compact fluorescent bulbs can be purchased with CRIs in the 70-90 range. Lighting experts target a CRI of 80 and above for visualizing true color.
Recessed lights that penetrate the building envelope (ceilings with attic space above) should be IC-rated (insulation contact) to signify fire-resistance and to prevent air leakage and energy loss. Other similar lighting fixtures should be caulked around the edge or gasketed to prevent air infiltration.
Northwest Energy Alliance lists fluorescent fixture alternatives to incandescents based on fixture wattage (click on Tools/Resources, then Fixture Tool). Information on ENERGY STAR®'s
Advanced Lighting Package and Seattle City Light's
efficient home lighting packages can also assist the selection process.
CFLs and Full Spectrum Fluorescent Lamps
Where existing incandescent fixtures can't or won't be replaced with fluorescent fixtures, compact fluorescent bulbs can be used to reduce the electricity usage. As an example, a 60-watt incandescent bulb can be replaced with an 11 to 15 watt compact fluorescent, for roughly a 76% reduction in demand. Although compact fluorescent light bulbs (CFLs) cost more than incandescent light bulbs,
each bulb saves $25 to $30 over its lifetime, and lasts 6-10 times longer than incandescent bulbs.
CFLs should be ENERGY STAR qualified to ensure quality and the long life that gives them a low life-cycle cost. ENERGY STAR qualified CFLs typically are no more energy efficient than non-qualified models, but they come with a minimum two-year warranty in residential applications, and should not flicker, buzz, or hum.
To maximize their benefit, use CFLs in high use areas. For lights that are used for only short periods of time, specify incandescents with dimmer switches, motion sensors, or timers.
(light emitting diode) technology, new to the residential lighting scene, uses 90% less electricity than incandescents. Because of LED's long life and additional up-front cost, they are suggested for difficult-to-service indoor and outdoor applications, and heavily used indoor areas. They can also be used in a variety of creative lighting layouts because of their size -- roughly that of small Christmas lights.
Dimmer switches allow one fixture to serve several lighting functions, such as task lighting when at full illumination and decorative or safety lighting at lower settings. Dimming increases lamp life and saves energy because less electrical wattage is used.
Incandescent lamps last longer when a "soft-start" dimmer is installed. Fluorescent fixtures require either a dimmable ballast or additional wiring. Dimmer switches and other lighting controls are rated for total controlled wattage, type of wiring, and type of fixture (electronic ballast, incandescent, or other). Visit Elflist.com for more information.
Some fluorescent lights and fixtures may also be put on dimmers. Be sure to check the product details because dimmers will shorten the life of CFLs that were not designed for this purpose.
Outdoor lighting is installed on many homes for safety and security. Adding motion sensors to outdoor lights can increase home safety. They turn the light on when they detect movement, usually within a range of 20 feet, and automatically switch off after a set amount of time. Because they limit the time that the lights are on, they can reduce energy use by up to 90%.
Occupancy sensors can also be used indoors in rooms that are used for short periods of time, such as hallways, bathrooms, workrooms, garages and closets. They are convenient because they allow for the hands-free use of lighting, which can be beneficial in mudrooms and laundry rooms.
Because they keep the lights on for only short periods of time, occupancy sensors should not be used with CFLs.
Inform the Homeowner
Much of the benefit of improved artificial lighting will diminish if the homeowners are unfamiliar with the features. For this reason, take the time to explain the fixtures, features, and controls to the users, and describe the benefits of using these features. You should also provide information on where they can purchase replacement lamps and bulbs. Always leave all warranty and maximum wattage information with the homeowner.
Content updated on 5/19/2009