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Before replacing lamps, consider controls. Simply turning off lights during non-occupancy times can reduce costs. Office spaces which are intermittently occupied are also good candidates for occupancy sensors. Sensors can detect motion and control lights in offices depending on occupancy. Many lighting systems can also be set to timers, adjusted around the average occupancy hours of the building. Certain sensors can automatically detect ambient daylight and readjust interior lighting without the need for seasonal resetting. (More about occupancy sensors.)
To increase lighting efficiency, buildings should make use of existing features. For example, using windows as light sources can decrease the need for indoor ambient lighting. (More about daylighting.) Where possible, spaces in front of windows should not be filled with furniture or window displays. Window glass should be regularly cleaned and can also be coated with a self-cleaning material.
Light-colored walls reflect more light than dark-colored walls and help maximize both daylighting and ambient indoor lighting. When renovating, making a simple choice about paint color can immediately result in cost savings.
Excessive ambient light can lead to high energy costs. Where possible, task lights should be used as an alternative. In task lights and other small fixtures, incandescent bulbs should be eliminated in favor of compact fluorescents. Incandescents give off more in heat than in light, and give off fewer lumens per watt than the equivalent in CFCs. (More about lumens and watts.) In other words, incandescents are wasteful because they produce low amounts of usable light but still draw significant power.
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Many large buildings, including retail and educational, have overhead fluorescent tubes as their primary lighting source. Identifying the tube type is important when addressing efficiency concerns. Until recently, T12 bulbs were widely used. Now, many owners are switching to T8 bulbs. Buildings which still use T12s can benefit from a switch to T8s. A T8 bulb has a longer lifespan, reducing purchasing and labor costs. While T12s tend to hum, T8s hum and flicker less, resulting in a more productive work environment. An efficient fixture will include an efficient ballast, the part of the fixture that regulates the current. For maximum savings, any remaining magnetic ballasts should be replaced with electronic ballasts. These lighting changes will also result in fewer emissions and less landfill waste. (More about fluorescent bulbs and ballasts.)