Lighting
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Lighting accounts for about 33% of typical commercial energy usage and can range up to 60%. In many cases, lighting is the most cost effective efficiency upgrade you can perform, especially with financial incentives from the utilities and other sources.
In almost all lighting retrofits, the lighting quality improves substantially and the product lifetime is longer. Most retrofits can be accomplished from below with ceiling without altering the wiring or building structure.
Since lighting consumes a great amount of energy we cannot overlook the no-cost saving opportunities such as:
- Turn off lighting in unoccupied areas.
- Turn off lighting when the building is vacant.
- Encourage occupants to turn their lights off when they will be out of the office for more than 15 minutes.
- If dimmers are installed, the lighting levels can usually be reduced without affecting occupant comfort. Because dimmers use energy, a lighting circuit with the dimmer left in the "full-bright" setting actually uses more energy than a simple switched circuit. It pays to use the dimmers you have installed.
- If dual-switch circuits are installed, use them to adjust lighting levels. For example, in an area with daylighting from windows or skylights, switch off one circuit when the daylight levels provide sufficient lighting for the area.
Various lighting technologies that can reduce energy usage and cut utility costs are briefly listed below. For more detailed lighting information, go to the Lighting section under Further Information.
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 T8/T5 Lamp with Electronic Ballast
Replacing magnetically ballasted T12 linear fluorescent lamps with electronically ballasted T8 lamps reduces lighting energy consumption by 20%. The thinner T8 and T5 lamps are approximately 40% more efficient than the thicker T12 lamps. In addition, they generally last 20% longer than the older T12s.
This combination not only provides savings on your electricity bill, but also reduces operations and maintenances costs. It also makes a T12 to T8 retrofit one of the most cost effective upgrades; two-year payback is typical and payback in a year is common for businesses with long hours of operation.
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 Compact Fluorescent Lamp (CFL)
Compact Fluorescent Lamps are five times as efficient as incandescent bulbs. They also last eight to ten times as long, and produce much less heat than incandescents do when they are on. This, in turn, can help to reduce the cost to cool your building.
Although the most common types are the exposed ones shown to the left, many have a plastic cover and look very similar to an incandescent light including reflector PAR type lamps.
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 Electronic Fluorescent Ballasts
New electronic ballasts are much more efficient than older magnetic ballasts for fluorescent lighting. Magnetic ballasts convert more of their input energy into heat, which creates two problems: extra energy consumption and extra heat for the HVAC system to handle.
There are two additional benefits to replacing magnetic ballasts with electronic units. Magnetic ballasts also produce noise due to the vibrations of the transformers and light flickering, which is especially noticeable when using a computer monitor. Electronic units eliminate the noise and the flicker.
Dimming ballasts allow the lighting levels to be adjusted, either with photocell, manual, or automatic controls. This control provides the perfect amount of lighting near windows and reduces energy wasted on excess lighting levels. Standard ballasts are not dimmable, but still provide all the other benefits described.
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Time Clock
Time clocks automatically turn lights on and off at preset times thereby saving energy and providing convenience. They are great for security lights or display areas such as storefronts.
Look for units that feature a minimum 3-hour battery back-up to avoid time-loss during power outages. For outdoor lighting without a photocell, use astronomical time clocks that follow sunset and sunrise.
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 LED Exit Sign
New LED (Light Emitting Diode) exit signs dramatically reduce energy consumption versus incandescent units. The incandescent lamps are only about 15% efficient. Since exit lighting is always on, this inefficiency is multiplied by 24 hours a day, 365 days a year.
Additional benefits of LED exit lighting are reduced maintenance costs due to the long life of LEDs and superior lighting that is more even and appealing.
Look for EnergyStar®-qualified units with a rated input of 5 Watts or less and a minimum life of 10 years. Retrofit kits are available.
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 Photocell
Photocells are often installed on outdoor lighting to ensure that the lighting is turned off during the day. Another use is in interior areas that receive significant amounts of daylight from windows and skylights. In these areas, the photocells can switch the lights on and off depending on the amount of daylight available. Some photocell controls can vary the lighting levels with the daylight to insure that the overall light level remains constant.
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 Lighting Occupancy Sensor
Occupancy sensors control lighting based on sensing the presence of occupants in a room. They are often installed in areas that have intermittent vacancy.
For example, they can turn the office lights off automatically when the occupant leaves for a meeting or for lunch. In a restroom or supply room, they can turn the lights on only when an occupant enters. Occupancy sensors can even switch lights off at the end of the day (although physically turning the lights off prevents the chance of unintended activation when the area is vacant).
Units are available to replace standard wall switches (as shown at left) or can be mounted separately on walls or ceilings. Wall switch units are the least expensive to install but may not provide full coverage of the area. Units to control plug in office equipment are also available.
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 LED Channel Sign
Light Emitting Diode (LED) channel lighting uses about 90% less energy than incandescent sign lighting. LED lighting also reduces sign maintenance and ensures even illumination. LED channel lights can be retrofit into existing signs. They are lightweight, very efficient, and produce high quality light.
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