Commercial grade UFO LED high bay lights are designed for environments that do not require high operating conditions such as big box stores, retail stores, automotive showrooms, commercial warehouses, convention centers, exhibition venues, recreation centers, gymnasiums and gyms.
Unlike industrial facilities, these environments are typically free from lighting challenges such as extreme ambient temperatures, dirty electricity, vibrations from large machinery, high humidity, corrosive atmospheres, aggressive chemicals and dust.
Today, the high bay lighting market is witnessing a rapid shift from fluorescent and HID technologies to solid state lighting based on LED technology. The complex composition of LED lighting systems has led to product designs swinging in different directions. Commercial grade UFO LED high bay lights are a distinct product category that is designed with an application focus.
Commercial grade UFO LED high bay lights are an architectural solution for commercial interiors with high ceilings. They are not just technical lighting fixtures, but are created to emphasize the desirable features of the building.
Commercial facilities, such as large retail operations and entertainment centers, require an energy-efficient lighting solution with a more sophisticated design than traditional industrial-looking high bay lights.
The miniature size and solid-state durability of LEDs give luminaire designers the ability to go beyond traditional form factors and create luminaires with the perfect combination of form and function. At the same time, these products offer energy savings based on significantly higher light source efficiency. Traditional metal halide and fluorescent lamps lack directional lighting capabilities. The luminous flux of these omni-directional lamps may be difficult to extract efficiently and redirect into a more useful uniform distribution.
The directional light output and smaller package size of LEDs provide an opportunity to achieve very high light transmission efficiency through precision designed secondary optics. The semiconductor nature of LEDs makes it possible to integrate the luminaire into a variety of lighting control systems so that the lighting meets the specific needs of the application or environment.
The ability to deliver the right amount of light on demand allows UFO LED high bay lights to achieve high lighting application efficiency (LAE), which translates into significant additional energy savings.
Mounting heights, light distribution, cost targets, lumen packaging, color characteristics, and the wide range of environments in which high bay lights must be compatible and integrated have led to a proliferation of luminaire types and performance variants.
The ultimate value of UFO LED high bay lights depends on the efficiency and reliability of the lighting system. These variables are further determined by the different components of the lighting system, including the light source, driver and control components, optical system and heat sink.
The trade-off between performance and cost inevitably becomes part of the design process of any luminaire. While achieving performance and cost goals simultaneously is a huge challenge, the mild operating environment in commercial facilities has a greater tolerance for the use of lower cost UFO LED high bay lights, which have a narrow operating window.
Today, high bay lighting systems offer many performance variants involving LED package metrics. Different luminous efficacy, lumen maintenance performance, color temperature, color rendering accuracy and lifetime depend on the design of the LED packages and how they are integrated into the lighting system.
Commercial grade UFO LED high bay lights are flourishing on the basis of reflective SMD LEDs using a plastic leaded chip carrier (PLCC) based packaging platform. The high light extraction efficiency achieved by highly reflective housings and leadframes enables PLCC LED packages to achieve much higher light source efficiencies than other types of LED packages, including ceramic substrate high-power packages, chip-on-board (COB) packages, and chip-scale packages (CSP).
When paired with high-efficiency drivers and optics, high bay lamps that produce white light using reflective SMD LED packages can have luminaire efficiencies in excess of 150 lm/W.
The high luminous efficiency can significantly reduce the payback period. Theoretically, this level of luminous efficiency could allow end users to break even on their investment within two years. There is a fundamental trade-off between color quality and efficiency.
Efficient LEDs are over-saturated in the blue and green spectral bands and under-saturated in the critical wavelengths that are essential to rendering vivid colors.
Often, vivid colors make for a rich visual experience in many retail and entertainment facilities. Complex and subtle colors can only be appreciated with optical radiation that has a balanced spectrum. The efficacy of high color rendering and warm white LEDs is greatly reduced due to Stokes loss and the eye’s low sensitivity to long wavelength light.
While the theoretical payback time of LED luminaires using high luminous efficacy mid-power LEDs is sufficient to entice purchase, the packaging-related failure mechanisms of these reflective SMD LEDs make the design and engineering of LED luminaires a serious challenge.
The lumen maintenance of PLCC LED packages is highly temperature dependent. Rapid deterioration of the packaging material at high temperatures can lead to a huge reduction in efficacy. Thermoplastic resins can discolor under intense light levels or prolonged operation, which can also accelerate lumen depreciation.
Unless the junction temperature of a plastic LED package is kept below the specified maximum operating temperature under all driving and operating conditions, the short life of a poorly designed LED luminaire will render its high initial efficacy meaningless.
To delay the onset of lumen degradation and chromaticity shift at high operating temperatures, higher performance products use EMC (epoxy molding compound) molded LED packages. EMC has better thermal stability than traditional PPA and PCT materials.
EMC molded LEDs are typically designed as quad flat leadless (QFN) packages, which provide an efficient thermal path that draws heat away from the active area of the LED.
Obviously, thermal management is critical to the continued efficient operation of all plastic LED packages. EMC-molded LEDs are no exception, as epoxy resin has limited thermal resistance. LED thermal management involves drive current control and heat dissipation.
In general, the higher the drive current, the more heat is generated in the semiconductor package. This in turn, accelerates the thermal degradation of the package material.
Therefore, maintaining the proper drive current is one of the important aspects of thermal management.
Thermal engineering of LED luminaires focuses on improving the ability of the system to draw heat away from the LED junction. In order to keep the junction temperature under control, the thermal resistance of components throughout the heat path must be reduced to ensure an easy flow of heat.
Commercial grade UFO LED high bay lights are typically less than 250 watts. Effectively designed passive heat sinks and the use of high thermal conductivity MCPCBs and TIMs can handle the thermal load without relying on active thermal management. The main problem is that the heat sink design may not be sufficient to reduce the total system cost.
Proper optical design is often as important as thermal management. By using secondary optics, not only can light be efficiently extracted from the light source, but it can also be evenly distributed to maximize the spacing of the luminaire, which can result in significant additional energy savings.
The optical transmission efficiency of an effectively designed optical system can exceed 90%.
High optical system efficiencies are typically achieved with lens arrays made of PMMA or polycarbonate. The lens arrays consist of multiple lens elements molded to provide individual optical control of the SMD LED array.
Total Internal Reflection (TIR) lens arrays can produce precisely controlled optical distributions from narrow to wide with efficiencies in excess of 90%.
LEDs are high flux density devices. Glare is produced by excessive brightness from concentrated emitters.
High bay lighting in commercial facilities should support an environment that creates a positive experience and engagement by providing visual comfort. Therefore, glare control is an important part of the optical design of commercial grade UFO LED high bay lights.