Examine Use Requirements and Design Before Choosing Lighting Fixtures
By Lindsay Audin
When looking at the life-cycle cost of lighting, it pays to parse all the pieces: not just the prices for fixtures, lamps, and ballasts, but also the costs for power to run them, the labor to maintain them, and services to dispose of them. Savings are possible that could cut the overall cost of illumination by 5 to 15 percent.
Most estimates are that 80 percent of the cost to operate a fixture is energy, with the remainder distributed between labor and parts. But such charts may not include the initial cost of the fixture, lamp/ballast disposal, and other charges. Fortunately, options exist to minimize these and other factors, including energy.
For the purpose of looking at the lifetime costs of lighting, and opportunities to contain and reduce them, the following examples use a typical recessed 3-lamp, 4-foot linear fluorescent fixture with standard T8 lamps and an electronic ballast. All costs are in today’s dollars, without escalations.
Start With The Task
Most spaces are illuminated to achieve tasks such as work, instruction, or sales. Each has an appropriate lighting level, but finding such excessive levels is common. Some corridors are lit as brightly as offices or classrooms, despite the fact that a much lower level may be satisfactory. The same may be true when a task changes. One college library space was converted to a cafeteria, with no adjustment to lighting levels. Many offices now filled with LCD screens are still lit as though typewriters were in use. The end result in all three cases is roughly double the necessary light level, which then doubles the operating and maintenance costs………………