Published on October 15th, 2007 | by Stephanie Evans

Energy Efficient Lighting

Energy efficient lighting is one of the five key elements of the Green Building Rating System from The Leadership in Energy and Environmental Design (LEED). Green remodeling with window placement is one way to achieve sustainability. Another less expensive method is the use of compact fluorescent light bulbs.

According to the Union of Concerned Scientists, if every U.S. household replaced just one regular incandescent light bulb with a compact fluorescent light bulb, it would prevent 90 billion pounds of greenhouse gas emissions from power plants each year. This equates to 7.5 million cars off the road. And the U.S. Environmental Protection Agency says that by replacing regular light bulbs with compact fluorescent light bulbs at the same minimal rate, Americans would save enough energy to light more than 2.5 million homes for a year.

Compact fluorescent light bulbs, or CFLs, produce light that’s more diffused than incandescent bulbs, so they are very good for area lighting. They also use roughly one-quarter of the energy an incandescent bulb uses to produce the same amount of light. Basically, it takes a 15-watt CFL to replace a traditional 60-watt bulb. Not only is there less energy use and less greenhouse gas emission, but CFLs produce less heat as well.

CFL’s are not only energy efficient—they produce less waste because they last longer. A typical incandescent bulb will last between 500 to 2,000 hours. Compact fluorescent lights are guaranteed for 8,000 hours, meaning that there are at least four regular bulbs thrown away for every CFL.

Switching bulbs is not the only method of sustainable lighting. Using the sun’s natural light (also known as daylighting) is one of the oldest tricks in the book for cutting down on the electrical bill. Today, new homes are designed and built with daylighting taken in mind. For those green minded folks who are remodeling an existing house, skylights and window placement can help achieve desired results. If daylighting is part of your carbon footprint reduction plan, there are a few things you can do to help create the best possible scenario:

To avoid glare, use window-sills, walls, louvers, reflective blinds, and other devices to reflect light deep into the building.

Take into consideration glazed windows. These transmit the most visible light while keeping out the most solar heat, which can raise the homes temperature in the summer months.

As far as the best directions for daylighting are concerned, north and south facing windows provide the best light. Windows facing south should be protected from the sun by an overhang. Avoid east or west facing areas for daylighting purposes unless they are shaded by trees or other means. An overhang will not block direct light for east and west orientations.