Hierarchical Life Prediction Model for Actively Cooled LED-Based Luminaire

The lifetime of an actively-cooled light emitting diode (LED)-based luminaire is dependent not only on the junction temperature of LEDs, but also on the reliability of active cooling devices. We propose a novel hierarchical model to assess the lifetime of an actively cooled LED-based luminaire that can provide light output equivalent to a 100 W incandescent lamp. After design considerations for LED-based luminaires with active cooling are discussed, the proposed model is described using component-level sub-physics-of-failure models. The model is implemented to predict the lifetime of a LED-based recessed downlight with synthetic jet cooling. The effects of the time-dependent performance degradation mechanisms of the active cooling device on the lifetime of the luminaire are also discussed.