WEB EXCLUSIVE: Will LED Lighting Work For You?
This Web Exclusive is contributed by Bluestone Energy, a national design/build engineering firm based in Norwell, MA. The firm is focused on the cost-effective reduction of energy use in commercial and industrial facilities.
Many facility managers (fms) know the feeling of the tall ladders, burnt fingers, clinging dust, and dead insects that go along with the routine process of changing a lamp. Office spaces, manufacturing facilities, lobbies, garages, and most other indoor and outdoor facilities require lighting in one form or another, and yet among many other fm tasks, lighting maintenance can be a costly and time consuming chore.
LED lighting improves sustainability by lowering the energy used to power fixtures, improves working conditions through directed light, and lowers costs by lasting much longer than previous lighting solutions.
Although the initial cost of installing LED lighting can appear overwhelming, the ROI of an LED retrofit usually occurs within five years of installation, for a lighting solution that can last for 10 years or more. Fms who are thinking about making the switch to LEDs should tackle two questions prior to a lighting retrofit. What do they need to consider before installing LED lighting and, once it’s there, how should they best evaluate if LED lighting is truly working?
Installing LED Lighting: Three Things to Remember
Whether a single lamp replacement or an entire facility retrofit, there are several elements of LED lighting to consider before making the change.
Temperature. Most LED fixtures have the ability to work in temperatures up to 135°F as well as applications well below freezing, making them flexible enough for most environments. The ability of LEDs to perform very well in cold spaces makes them ideal for freezer applications where traditional fixtures have needed special technologies added to continue to perform properly. In addition, LEDs in this environment can see extended life and increased savings versus other fixture technologies due to the fact that they can be cycled on and off quickly, such as when occupancy sensors installed, with no effect on performance due to temperature. Other fixture technologies can need up to a half hour to warm up before they are producing the same light levels again.
Color. Color temperature for lighting is described in the unit of absolute temperature, known as the kelvin (K). Color temperatures of 5,000K and above are called cool colors (blueish white), while lower color temperatures (2,700 - 3,000 K) are called warm colors. High Intensity Fluorescents (HIF) can produce a range of colors but other fixtures such as those based on metal halide and high pressure sodium technology are more limited, especially in outdoor applications.
LED has the ability to natively produce a variety of colors that can suit a particular facility’s needs. For example, some manufacturing facilities that need to spot defects in materials or finished products may opt for higher color fixtures, from 4100K and up, as these colors more accurately resemble natural light.
LED lighting natively generates light in a specific color with fixtures that direct a majority of the light directly from the fixture to the space. This is an advantage over fluorescents where due to the nature of using lamps some of the light must first be reflected up and then back down to the facility. This is why while both technologies can offer color temperatures to suit different needs, LED fixtures can use less energy for the same color at the same light levels.
Life Cycle. LED lighting can be dimmed without affecting the life of the fixtures, and frequently switched on and off with no negative consequences. This is useful in applications with sensors where the fixture can be shut off when the area is not in use, or dimmed when outside light is measured to be maintaining light levels. A well-designed fixture can retain 90% of its initial output after 70,000 hours, nearly twice the life of "long life" fluorescent sources. The longer life cycle does not pose environmental problems either, as fewer fixtures will be required over time, and because, unlike traditional lighting choices, LEDs do not contain hazardous materials. The life cycle of LEDs means fewer hours on the ladder and more time spent on other facility needs.
Evaluating LED Lighting: Is It Worth It?
Once a lighting retrofit has been performed, fms need a way to evaluate how the lighting is working, and evaluate that the benefits have been worth the change.
Physical Benefits. Lighting is measured in lumens, which captures the delivered light to a surface. LED lighting has more precise direction of light from its fixtures, and in many cases its optics can be adjusted to point more accurately at the target area. This better efficiency often means that for larger facilities or manufacturing retrofits, a one-to-one fixture replacement is often not necessary.
Measurable Results. Although the starting expense can appear ominous at the point of installation, if fms chose LED lighting, these retrofits usually have a payback period of around three years, and sometimes even less. The initial cost is something to consider, but the benefits of LED energy savings and maintenance savings due to a much longer time before failure make a higher installment cost well worth the effort. In addition, many state and local utilities offer significant rebates that can pay for up to half the cost of the installation in certain areas. For fms curious about their own potential projects, there are online calculators to help discover a facility's predicted ROI for an LED installation.
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