Influence of luminaire aiming on LED sources junction temperature

The correct selection of the radiator and ensuring the optimal cooling of the LEDs is the key element associated with the long life and stability of LEDs parameters. Currently, the most widely used radiation system in luminaries with LEDs is the passive system, where the main flow path of heat is the free convention between the radiator and the environment. In the above radiation system, apart from the geometry and size of the radiator, the junction temperature of the LED of the luminaire can also be affected by the angle of inclination of the luminaire relative to the gravity vector. The article presents the results of simulation studies, related to the designation of the junction temperature of the exemplary luminaire in the LED technology, for a different location of the fixture relative to the gravity vector.