The outdoor lighting of areas like streets, roadways, parking lots, and pedestrian areas is currently dominated by metal halide (MH) and high-pressure sodium (HPS) light sources. These are relatively energy-efficient light sources that have been in use for many years and their performance characteristics are well-understood. The rapid advances in LED technology have resulted in a new
option for outdoor area lighting, with several potential advantages over MH and HPS sources. There's no doubt that well-designed LED area luminaires can provide the required surface illuminance using less energy and with improved uniformity, compared to HID sources. This has forced many businesses to reevaluate their lighting choices, given the benefits of energy-efficiency and reduced maintenance of LED area luminaires.
In this blog, we will explore the 5 traits of area lighting luminaires that make them highly reliable and allow their users to be at ease at all times.
1. Excellent Energy Efficiency
Many aspects are considered in the design and specification decisions for outdoor area lighting. Energy efficiency is especially a priority in this application due to the long-running hours and relatively high wattages typically involved. As would be evident from the graph above, LEDs fare much better in this department with high lumen efficacies as compared to their traditional counterparts.
High lumen efficacy aside, LED area luminaires are also well known for their high energy effectiveness.
(Source: Energy.gov) The table above compares measured illuminance data from a recent installation of LED outdoor luminaires and existing 70W HPS. Observe the high Max/Min Ratio for the HPS based luminaire which suggests poor light uniformity as compared to its LED counterparts.
According to Energy.gov, the energy effectiveness of an area luminaire depends on the luminous efficacy of the light source and appropriate power supply in lumens per watt (lm/W), the optical efficiency of the luminaire (light fixture), and how well the luminaire delivers light to the target area without casting light in unintended directions.
So, the best area luminaire delivers the necessary illuminance in the target area, with appropriate lighting quality, for the lowest power density.
Given that HID lamps are high-intensity near-point sources, the light is more concentrated in the areas below the luminaire as compared to the areas farther away.
In contrast, the smaller, multiple point-source and directional characteristics of LEDs allow better control over light distribution, with stunning light uniformity. This difference is evident in the comparison table above, where “hot spots” are visible under the HPS luminaires. This overlighting represents wasted energy. This phenomenon also has the potential of causing glare, which hinders visibility.
2. Extreme Durability
One of the most basic decision factors for choosing an area luminaire is its lifetime. Long life is potentially a key advantage of LED area lights over other light sources.
According to DOE's data, typically, a large, statistically-significant sample of traditional area luminaires that are operated until their rated life has failed. LED area luminaires on the other hand usually do not fail abruptly like traditional light sources. Instead, their light output slowly diminishes over time.
Most LED area luminaires and retrofit lamps available today often claim long life, for instance, 50,000 hours or more. These claims are based on the estimated lumen depreciation of the LED chipset used in the product and often do not account for other components or failure modes.
When LEDs are installed in a luminaire, there are many factors that can affect the rate of lumen depreciation or the likelihood of catastrophic failure. Usually using luminaire components of the same rated life as that of the LED chipset solve this problem. A credible trait of a durable area luminaire is if its long-life claims are backed up with appropriate manufacturer warranties.
Take, for example, IKIO's Amparo Area Luminaire. Its rated 100,000 hours of lifetime is backed up with a 10-year warranty, which guarantees its users a reliable and durable area lighting experience.
3. Robust Built
Given that area luminaires are outdoors, they often become perches for birds and the debris that comes with them. The luminaire should not collect and retain dirt or water on the top side, and the optical chamber should remain clean for the LED luminaire to truly reduce maintenance. Ingress Protection (IP) ratings describe the luminaire’s resistance to dust and moisture penetration. Look for an IP rating appropriate to the conditions in which the luminaire will be used. For example, an IP rating of 65 indicates that the fixture is dust-tight, and protected from water projected from a nozzle. Whereas IP66 such as for the case of area luminaires like the IKIO Amparo suggests that the fixture is dust-tight and protected against heavy seas and powerful jets of water.
4. Cutting-edge Light Controls
LED area luminaires are much newer outdoor lights as compared to luminaires with legacy light sources. And in this day and age of technology, these luminaires are no exception to that. Advanced light controls integrated with LEDs are a perfect way to ensure effective utilization of illumination and also greater degrees of energy efficiency. Not just that, they prolong the duration of the luminaires. Most area luminaires come equipped with daylight harvesting technologies.
Daylight Harvesting is the industry term for adaptive lighting technologies that take advantage of daylight hours to offset the amount of electricity needed to effectively light a given space.
Light sensors and switching/dimming controls are matched together and programmed to take advantage of existing sunlight. Harvesting systems allow lighting levels to be varied based on activity levels or the time of day, and there’s currently a strong push by exterior lighting decision-makers to make better use of these cost-saving technologies.
Again, IKIO's Amparo area luminaire is a great example of such outdoor luminaires. Apart from daylight harvesting, these luminaires come with motion sensors which dim or increase the intensity of the light detecting people or moving objects. This has great utility in parking lots, where luminaires can automatically control the illumination levels. Harvesting systems and occupancy sensors are often bundled in the luminaire system to be controlled by wireless systems like a remote or from an app, greatly enhancing their easy access.
5. Versatile Mounting Options
Area luminaires are a perfect alternative to traditional lighting technologies offering a variety of solutions to illuminate parking lots, parking garage roofs, and general area lighting. And naturally, multiple mounting options increase the scope of their application. And because of this, the newest LED area luminaires offer multiple mounting options. These allow adjusting the fixture to the required levels or adapt to existing access points, all while saving energy and money. The most common fixture mounting options include square pole, round pole, wall mount, trunnion mounting, floodlight mounting or slip fitter mount for 2-1/8" to 2-3/8" tenon.