LED - Heat management
LEDs have a limited life, typically up to about 50,000 hours. An LED's life span is considered to be the point at which the output intensity drops below 70%, as shown in the following graph. Before this point is reached there will however be a gradual reduction in efficiency. In addition to producing light, LEDs also generate heat. This heat energy needs to be transmitted away from the active LED chip as the structure can be adversely affected by a sustained high temperature. Overheating the LEDs can cause total failure or accelerated ageing.