Service by Medallion Suggests Four Lighting Options That Help Reduce Energy Costs
The U.S. Energy Information Administration (EIA) estimates that in 2017, the U.S. residential and commercial sectors used about 273 billion kilowatt-hours (kWh) of electricity just for building lighting. This was about 10 percent of the total electricity consumed by both of these sectors in 2017, and about seven percent of total U.S. electricity consumption.
While many facility managers (FMs) looking to reduce energy costs focus on lowering their facility’s heating and air conditioning needs, we should not overlook the savings that are possible by installing new and not so new lighting controls. And a good thing about this is that many are very cost-effective, so the savings can be realized rather quickly.
Here are four ways to make this happen:
These systems are designed to switch lights on and off based on available daylight. While the concept is worthy, early systems did not always work all that well. They either turned on lights too early, too late, or too abruptly.
Newer systems use dimmable fluorescent or LED lightbulbs. Light input changes are made gradually, so no one is left in the dark and FMs need not wonder why all the lights are on so early. It is estimated these systems can produce savings of up to 30 percent.
While this system is often found in commercial buildings, it appears to have found its niche in parking garages. Original bi-level lighting systems involved separate circuits going to different light fixtures. At designated -8-20times; timers would turn on and off different circuits. This could produce savings of up to 50 percent.
Today’s bi-level switching systems are more sophisticated. Most do not need separate circuits and instead of depending just on timers, they can also turn lights on and off based on the amount of daylight detected or triggered by movement in an area. While the savings can vary, it can be as high as 70 percent, depending on the system installed.
While timers are one of the oldest ways to reduce the amount of energy used for lighting, these systems still have a lot of value today. Newer systems can be pre-set, but they are also designed to turn lights on and off earlier than set if the photosensor detects the area needs or does not need lighting. This helps address seasonal light changes, especially when these systems are used outdoors. While the savings may not be as high as the other systems just mentioned, FMs can expect to reduce the amount of energy needed for lighting by 10 percent to as much as 20 percent.
These systems are now installed in public restrooms, offices, and even homes. Very simply, when they detect activity in an area, they turn lights on. When they detect no movement, lights go off. But, occupancy sensing systems do not all work the same way. There are three basic types:
Passive infrared turns lights on if the system detects body heat in each area.
Ultrasonic detection sensors emit a high-frequency sound wave that bounces off walls, objects, and people. Any movement in an office, for example, will cause changes to this high-frequency sound wave. When it changes, the lights come on.
Dual-technology combines the best of both passive infrared and ultrasonic detection. With these systems, lights are turned on and off using both technologies, helping to eliminate false activation/deactivations. FMs are advised to use dual-technology systems in larger indoor areas. These systems can reduce lighting energy consumption by about 25 percent.
These technologies have other benefits beyond just reducing energy needs for lighting. For instance, they can also help reduce the amount of heat emitted by light fixtures, potentially reducing air conditioning needs. Further, they can extend the service life of lighting sources.