Claudette Reichel | 6/25/2008 10:09:56 PM
Lighting can account for 15% of a home’s yearly electric bill. Lights not only use energy to operate, they produce heat that must be removed by the air conditioning system. Energy-efficient lighting saves on electric bills, helps keep the home cooler and lasts longer than traditional incandescent lighting.
High color fluorescent lights: Fluorescent lighting has improved dramatically. Lamps with a high color rendition index (CRI) create a flattering, natural light similar to incandescent or daylight. Fixtures now use electronic ballasts that don’t flicker or hum, and dimmers are available. Fluorescent lighting lasts about 10 times longer, uses about one-third of the energy and creates about one-third of the heat of incandescent lighting.
Compact fluorescent lamps (CFLs) can fit in many standard light fixtures. Although they cost more than incandescent bulbs, you come out way ahead over the life of the CFL because of its much longer life and energy savings. (Figure 1, Compact Flourescent Lamps)
LED lights are extremely longlasting and energy efficient. Although more expensive, costs are expected to come down as their market grows.
Outdoor lighting: Exterior security lighting can cost hundreds of dollars a year to operate if it is not energy efficient. Greatest savings are with outdoor fluorescents and high pressure sodium fixtures for security lighting. Add motion sensors or photo cells to operate lights automatically.
Daylight: sunlight illuminates the home without excessive heat gain. The layout should provide most rooms with north- or south-facing (with overhangs) windows, dormers, clerestory windows or solar light tubes (a domed roof fixture coupled with an insulated reflective tube that provides reflected light with little solar heat gain). Other skylights are not generally recommended; they allow too much heat gain unless they have a very low SHGC. Consider only storm-resistant skylights and ensure strict adherence to proper flashing. Skylight water leaks are common and tend to create more damage than window leaks.
Light-colored interiors: Light-colored interior surfaces increase lighting efficiency by reflecting light rather than absorbing it. Fewer fixtures and lower wattages are needed with light color schemes.