By Jason Duncan
From the April 2018 Issue
Not all lighting is created equal. This is especially true of exterior lighting retrofits. In these types of retrofits, cost savings, sustainability, and overall ROI stem from a facility executive properly identifying their goal—whether that be public safety, energy/cost savings, or another objective—and choosing the right type of lighting to meet that goal. Whether an exterior retrofit is a current priority or not, there are several factors to consider at the outset to ensure long-term ROI.
What Lighting Is The Best Lighting?
The “best lighting” choice often comes down to what matters most to a facility executive: short-term cost or long-term benefit? In today’s facilities, high pressure sodium (HPS), metal halide (MH), and fluorescent are the three most common types of exterior lighting—largely due to their lower price points. However, that lower cost is balanced by an increased need for frequent and ongoing maintenance.
Meanwhile, LED lighting is emerging as a choice for facility managers willing to invest on the front-end in order to reap a longer-term benefit. With rated lifetimes of 10 to 20 years, LED lighting can be designed to produce the same amount of light as traditional sources while lasting 10 to 50 times longer. Although LED fixtures generally cost more up front, the reduced maintenance more than makes up for the cost difference. Additionally, LED fixtures can save facilities up to 70% in energy usage—which case studies have demonstrated can reduce overall electric operating costs by 25-33%. Weighing this endurance, lack of maintenance, and competitive performance against its higher price point, LED lighting is often the smartest investment for facility retrofits.
Types Of Exterior Lighting Fixtures
When it comes to exterior fixtures, there are five main types:
- Roadway lights, which line streets, alleys, and other thoroughfares
- Bollards, which are typically two to three feet in height and line walkways.
- Wall packs, which are mounted on buildings 15 to 25 feet off the ground and shine light onto the immediate perimeter of a facility
- Uplights, which are mounted in the ground and shine light up at a building, flag pole, etc.
- Pole lights, which are used to provide light in parking lots
It is important to make sure that the type of LED a facility selects is designed for the type of light fixture being retrofitted or replaced. For example, it is not best practice to use a roadway light in a parking lot or vice versa. Yet, this recommendation has been made by some contractors as a way to reduce upfront costs. This is not a good choice to make. Choosing the right light for the right fixture is very important.
How Much Wattage Is Needed?
Higher wattage means higher energy usage, which ultimately translates into a higher electric bill. Not every facility needs the same amount of light output. With LED lighting, facilities get significantly more lumens per watt, allowing them to reduce overall wattage thereby reducing overall electric operating costs.
For virtually all facilities, the motivation behind an exterior retrofit center around achieving cost and energy savings. However, facilities like distribution centers and warehouses with loading docks often have the added consideration of needing to provide moderated visibility.
For example, one large retail distribution center in Tennessee replaced each of its 1000-watt HPS wall pack lights with a 90-watt LED fixture (see photo above). Following the installation, delivery drivers expressed their satisfaction with improved visibility when backing their trucks into the loading dock at night. The new LED wall packs directed the light in a way that didn’t shine into their rear-view mirrors and eliminated glare. Previously, drivers would be forced to adjust their mirrors to avoid the glare of the HPS lights.
This lighting retrofit project in Tennessee additionally reduced the distribution center’s annual electrical cost on those light fixtures alone from $40,770 to $3,330 per year.
The Case For Increased Light Output
On the flip side, certain facilities need to increase the light output of their exterior lighting. One of the primary motivations behind this is public safety—often a specific concern for banks, hospitals, schools and retail parking lots where insufficient lighting can be cited as a contributing factor to a crime. Increased exterior lighting output can also be needed during winter nights when the sun sets earlier in the day.
In one example, a bank chose to install a higher lumen output LED exterior lighting system after a tragic event occurred in its parking lot overnight. The executives of the bank reasoned that brighter lights would have helped deter people from loitering on the bank’s property and may have helped to completely avoid the tragedy.
The Sustainability Factor
An energy efficient lighting option like LED—which uses up to 70% less energy than typical exterior lighting sources—can support an organization’s sustainability efforts, such as LEED certification where buildings can earn up to an estimated 20 LEED points for optimizing energy performance.
Additionally, certain types of LED lighting can qualify a facility for dark sky compliance, leaving the night sky visible to visitors and the surrounding community. [Editor’s Note: The International Dark-Sky Association is a resource on dark sky compliance.]
The Color Of Light
Another factor to consider in a lighting system is its color rendering index (CRI) and correlated color temperature (CCT) ratings. HPS and MH lighting often have lower CRI and CCT than LED lighting. Low CCT gives off yellowish light, and low CRI makes it difficult to distinguish colors. Studies have shown that bluish light in some exterior lighting–typical of some poorly made LEDs–can be harmful to surrounding night life, disrupting the circadian rhythm of humans, plants, and wildlife. In order to maintain a proper circadian rhythm, artificial lights in outdoor spaces should mimic the warm tones of the setting sun. There have been cases where cities installed bluish street lights only to receive complaints that wildlife had been disrupted or that neighbors were having trouble sleeping.
It is important to note that LED lighting can be designed to meet practically any CRI or CCT. While some LED lights have a bluish tint, not all LEDs give off blue light—that is rather a matter of design.
Another case for color can be seen with facilities such as car dealerships or showrooms which benefit from lighting with a high CRI and designed with the correct CCT to make the colors of products pop, leading to increased sales.
The Ultimate Choice
For facility executives exploring options and ROI related to an exterior lighting retrofit, the first step is to identify the facility’s primary need—whether that be increased safety, managed visibility, heightened commercial appearance, energy/cost savings, or all of the above. An experienced lighting design and installation team can then help executives create a plan that not only delivers options but appropriate solutions. Because the ROI of an exterior retrofit can be seen across the board—from financial to environmental—an investment in an energy efficient lighting system today can translate into substantial savings tomorrow.
Duncan is President and CEO of Energy Lighting Services, a commercial lighting contractor specializing in the design, installation, and maintenance of commercial building lighting systems. He is a member of the Tennessee Hospital Association and the Tennessee Hospital Engineers Association. Energy Lighting Services was founded in 2010 and is based in Hendersonville, TN.
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