LED, Heat Sinks, & Thermal Management
LEDs are known as solid state technology. This means no glass bulbs, gases, mercury, or filament. LED light is simply, light that is produced very efficiently. As a current is passed through the diode, a small amount of heat is released backwards. Most well-designed LED lighting systems require the use of a heat sink to reduce thermal stress.
As the need for more efficient lighting technology gains momentum, one of the key challenges faced by the LED lighting industry today is thermal management. An LED that has been exposed to high heat or thermal stress will typically lose efficiency which diminishes its brightness and lumens-per-watt output. If there is too much or poorly vented heat and the LED is unable to reduce the temperature to the manufacturers recommended levels, a breakdown, or other undesirable effect may occur. For this reason, most LEDs and the accompanying luminaires are equipped with high-performance aluminum heat sinks capable of removing thermal stress that occurs in most modern LEDs.
Excess thermal stress can affect the short-term and long-term performance of an LED.
Long-term Performance Affected - accelerated lumen depreciation and shortened LED lifespan.
Short-term Performance Affected - color shift and light output reduction.
There are two types of heat sinks that are used in modern LED technology. Natural (passive) technology and forced (active) technology. Natural or Passive Cooling Technology passive cooling refers to eliminating the use of additional energy-consuming cooling components (fans, pumps, etc.) for efficiency. Aluminum heat sinks have become the industry standard for natural cooling. They have a finned metal encasement that diverts excess accumulated heat away from the lighting system.
Forced or Active Cooling Technology active cooling refers to LED cooling systems that contain energy sucking, moving components to effectively cool the system. This type of cooling is typically necessary for brighter or high lumen lighting. The goal of most LED thermal management systems is to remove the heat that occurs during normal use. To get the best performance and minimize the risk of damage and degradation, LEDs should have a properly designed heat sink. Effective LED cooling with a heat sink is essential for the long term performance of the lighting system.