Major lighting manufacturers now offer more energy-efficient and lower wattage
fluorescents. While some of the replacement lamps may yield slightly less
light, this may be perfectly acceptable in areas that were previously overlit.
Furthermore, when clean new lamps are installed, and the diffuser and reflecting
surfaces of the fixture are cleaned, there may be an increase in light output
even with lower wattage. However, it will be important to keep the fixtures
clean to maintain acceptable light levels.
Installing energy-saving or higher efficiency lamps is the easiest way to reduce energy consumption in ceiling lighting. All it takes is a ladder, the new lamps, and something to clean the fixtures with. When selecting new fluorescent lamps, make sure they are compatible with existing ballasts. It may be cost-effective to replace the ballast as well.
Some fluorescent lamps are referred to by their diameter. A one and one-half inch diameter lamp, which is 12-eighths of an inch, is referred to as a T-12. Without changing the ballast, standard four-foot, 40-watt rapid start lamps (F40-T12) can be replaced with energy-efficient 32-watt or 34-watt T-12 lamps that save 15-20% in energy with slightly reduced light output. 32-watt T-12 replacements should not be used in fixtures that will be switched on and off frequently. If you need more light than a standard 34 or 32 gives, there are T-12 Triphosphor lamps that have higher light output. Energy-efficient replacements are also available for eight-foot fixtures.
An improvement over energy-efficient T-12s is the T-8 lamp. At 32 watts, the slim T-8 four-foot fluorescent tubes offer even greater energy savings. Its smaller diameter adds to its ability to produce more light for less energy. T-8's, however, must be matched with appropriate ballasts. Installing 32-watt T-8's with new ballasts to replace your 40-watt lamps will save you energy dollars with little or no reduction in light output. With the highest efficiency electronic ballast, a T-8 will actually draw only 25-28 watts. When replacing burned out ballasts, and in new fixtures or retrofits, you should definitely consider T-8's.
Higher efficiency, 40-watt, four-footers for use with existing ballasts are known as T-10s. Their high lumen output makes them useful in areas being delamped where more light is needed than the remaining standard lamps can produce.
Fluorescent lamps come in many varieties, not only wattage and size but also in color. They have different color temperatures, which determines what color they look when you look at them. And they have different color rendition capabilities that affect what color objects appear under them. True color rendition is especially important for merchandise displays, grocery stores, beauty salons, and in industrial applications where the work being performed requires color matching.
It's hard to believe, but in many cases, it pays to replace your present lamps with energy efficient ones even before they burn out. So much energy may be saved that its value will soon offset the cost of the new lamps. And this is true even if your present standard lamps are relatively new since the life of a fluorescent is as much as 20,000 hours, it might take you 10 years to wear out a recently installed standard fluorescent during which time you would use extra electricity worth considerably more than the cost of a replacement lamp. If your fluorescents are used very infrequently, it may not pay to install the new energy efficient lamps until the old one have burned out.
