It is critical for optimum lighting performance in high temperature industrial environments as high temperature can cause degradation of lighting performance and industrial environments require LED high bay lamps that can withstand high temperature. Ambient temperature doesn't actually affect LED fixtures. Therefore, temperature control of luminaires is the leading issue for maintaining lighting performance in high temperature industrial environments. Heat is dissipated by conduction, convection and radiation. One of the key points to achieve optimized temperature control is to accelerate the heat dissipation and the other is to provide the heat resistance of the armature components.
The heatsink is one of the most effective ways to help high bay lights dissipate heat. The heatsink is a structure that transfers the heat from the LEDs to the air, reducing the heat accumulation in the connections and LEDs. In order to increase the heat dissipation efficiency, the heat sink is built in large surface areas. Blades and ducts are common structures to expand their surface area and allow adequate airflow. Material with greater thermal conductivity is also beneficial for heat dissipation. Aluminum is a typical heat sink material used for industrial environment. The size of the cooler is determined by the ambient temperature. In higher temperature environment, larger heat sink is needed. Robust heat sink reduces lumen wear and subsequently extends operating life in high temperature industrial environments.
The containment system is essential for heat resistance and thermal control of high bay lights. It plays an important role in protecting LEDs from high ambient temperature and providing higher thermal conductivity. Aluminum was chosen as the common body material due to its excellent performance in heat dissipation and easier manufacturing process. Various fabricated processes are available for the aluminum body. Extrusion, forging, casting and stamping are common and cost-effective aluminum production methods. Higher aluminum purity means better thermal conductivity as well as higher cost. The surface coating of the enclosure is one way to resist corrosion and increase emissions. An enclosure painted with acrylic power cost coatings has more thermal radiation than an unpainted one. Most enclosures of high bay lights are manufactured with vertical cooling ribs. These vertical ribs work well at preventing dust deposits and reduce thermal radiation barriers from the LEDs to the air.
LED drivers, also called LED power supplies, provide and regulate the power to the LEDs. Drivers are sensitive to high temperature. Excessive operating temperature will affect reliability and shorten the life of the drive. Failures of luminaires are often caused by poor performance of the drive. Also, drivers generate heat when powering the LEDs. Drivers cause strong thermal stress to the LEDs, resulting in reduced lumen output. Precautions should be taken to remove heat from drivers and LEDs. Aluminum enclosures are used to improve heat dissipation and ease the thermal load on the drives. Insulating the driver from luminaires reduces heat build-up and speeds up heat dissipation, ideal for high temperature applications. Separating the drivers also contributes to reducing the heat stress on the LEDs.
