There are many ways to save money on your lighting bill. A number of suggestions in this section are simple and inexpensive. More complicated or costly modifications to your lighting systems may have less complicated alternatives and should be thoroughly analyzed before proceeding.
Also, keep in mind that not only do different tasks require different light levels, but some workers in general require more light to do the same tasks as other employees.
When thinking about your particular needs, keep in mind that lighting energy can be wasted in three ways:
In order to choose the best lighting for a particular application, you need to consider qualities besides energy efficiency. Where several lighting types work equally well, you can make your decision based on initial cost, lamp life and efficiency.
The old standby has many advantages. They're cheap, versatile, easy to focus, have no strobe effect, and require neither ballasts nor warm-up periods. On the other hand, incandescents are inefficient, short-lived, vulnerable to voltage fluctuations and add to HVAC load.
They offer true color rendition, evenly distributed illumination, no warm-up, good efficiency and long life.
Tungsten, Halogen or Quartz Lamps
They look like conventional incandescents, but special filaments give them relatively better efficiency and longer life.
High Pressure Sodium Vapor
They are an excellent choice for street lighting, industrial applications, outdoor or (occasionally) indoor commercial lighting. Sodium is very efficient and long lasting. These lamps require a ballast and a warm-up period.
A source of versatile and efficient lighting, they have a cool white color range. Lamps require a ballast, and some require a two to five-minute warm-up, and a 10-minute cutoff between illuminations.
They are a source of bluish white color with relatively long life. They are less efficient than sodium or metal halide. For this reason, they are being replaced in most applications by metal halide.
Removing one 100-watt bulb that runs nine hours per day can save over 300 kilowatt-hours during an average year.
Because lighting needs in many businesses are steady throughout the workday, any reduction you can accomplish will affect your peak demand as well. Reduced lighting may have some effect on your air conditioning costs, too.
Finally, if you want to increase the amount of light you get per watt of electricity, as well as lower your lamp replacement costs, switch fixtures and/or lighting types where appropriate (see "Light Sources above").
Remove Unnecessary Lamps
You may be using more light than you need in areas near windows, as well as in hallways and unoccupied space. You can remove lamps based on your own best judgment, or use a light meter that will give you readings in footcandles.
Table 10 gives you an idea of how much you can save by removing even a few 40-watt fluorescent lights. Note that multiple lamps are wired in pairs, meaning that both lamps will stop working when one is removed.
On four-lamp fixtures, take out the two outer or inner lamps. If you can eliminate large numbers of fluorescents, experiment with different patterns for the best aesthetic effect.
Disconnect or Replace Ballasts
Ballasts maintain the proper current and voltage for your fluorescent lamps.
When you remove lamps, you should also disconnect the ballasts, because they still draw electricity when the switch that controlled them is turned on. There will usually be one ballast for each pair of lamps in a multiple lamp fixture.
When ballasts burn out on fluorescent lamps that are still in operation, replace them with new high-efficiency models that draw less power.
Reduce Lighting Where It Isn't Necessary
If your building gets plenty of natural light, experiment with cutting off lights near your windows.
Also, a number of areas may remain lit even when not in use - restrooms, kitchens, storage facilities and some offices. You can cut off lights manually, or investigate lighting motion detectors that automatically shut off switches if there's no movement in an area for a certain amount of time.
Finally, if your light switches control exceptionally large areas, it may pay to rewire so you'll have control over little-used space.
Clean Lamps and Fixtures
By keeping dust, grease and dirt off your lamps and reflectors, you can realize an effective increase in illumination up to 30 percent. This can reduce wattage requirements or allow you to operate with fewer lamps.
Avoid Light Buttons
The manufacturers of so-called "light buttons" claim their products will lower the energy cost of incandescent lighting. While they do extend the life of bulbs, they reduce light output more than energy use. You'll be better off switching to lower-wattage bulbs or using dimmer switches.
If you have timers controlling your lighting systems, you'll need to adjust timers for such variations, as well as daylight savings time, weekends and holidays. If you have a timer that can be set manually, check to see if all its pins are secure and in the correct positions. On most seven-day timers, you should see seven pairs of pins if the clock is working properly. (Don't forget to reset your timers if power has been interrupted.)
Switch to High-Efficiency Fluorescent Lamps
New fluorescent lamps and electronic ballast producing systems use up to 38 percent less power for equal amounts of light. If an area is currently over-lit, using new technology fluorescent lamps and reducing light output can result in even greater savings.
There are things to consider before you make wholesale lamp changes:
Table 11 shows typical savings for retrofitting fluorescent fixtures.
Use Lower-wattage Incandescents
If you've determined by estimate or light meter that portions of your space are over-lit, you may want to reduce the wattage of your incandescent bulbs rather than removing a percentage of them. The savings may be just as great, and the results will be more pleasing to the eye.
Lighting For Video Display Terminals
VDTs (also referred to as Cathode Ray Tubes or CRTs) are common in offices. Improper lighting can result in worker discomfort and fatigue.
Factors to weigh in determining VDT lighting requirements are the light generated by the screen itself, work areas adjacent to the screen, keyboard lighting, and other tasks performed in the same space.
If your employees use VDTs for a significant portion of their time, it would be advisable to consult a lighting specialist.
Replace Incandescents With Fluorescents
Fluorescent lamps that screw into standard incandescent fixtures are available. Where aesthetic considerations allow it, this is a very simple way of increasing efficiency and extending lamp life. Compact fluorescent lamps typically use 75 percent less energy than incandescent lamps for the same light output. They also have over 10 times the lamp life of an incandescent lamp.
Other Lighting Ideas To Consider
Sodium vapor lights are extremely long lasting and highly efficient lamps that cast a golden-yellow glow. Use them for parking lots, exterior lighting, storage space and other applications where accurate color rendition is not important.
Install timers to turn lights on and off at preset intervals, or photosensitive units that react to changes in natural light.
Add switches to give you control over different areas of your business.
Lower ceiling fixtures to bring light sources closer to work areas. You may be able to remove lamps or use lower wattage bulbs as well.
Use more natural light with blinds, shades or reflective film to reduce glare and heat buildup in summer. Rewire if necessary to turn off lights near windows.
Replace all inefficient lamps instead of waiting for them to burn out. If your energy requirements justify it, the new lamps may be a better investment than continuing to pay higher lighting costs.
Remove lights over stacks.
Move desks and partitions if possible to take better advantage of existing lighting.
Replace all incandescents with fluorescents - it's a major expense, but worth the cost if you use your lights a lot.
Replace lenses, diffusers and globes if they're yellowed or hazy. Acrylic remains bright longer than glass.
Repaint with lighter interior colors - the increase in reflectivity may allow you to use lower wattage bulbs or remove lamps.
Install task lighting that brings illumination to the job, especially for activities that require high light levels, like writing, drafting and product assembly.
For additional information: The U.S. Environmental Protection Agency (EPA) Energy Star Program can provide you with additional information and resources. Contact EPA Greenlights at 1-888-STAR-YES.
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