Thermal Impact of Bulb Emissivity and Reflector Finish in Automotive Lighting

Automotive lighting design trends often impact the performance and function of lamps. Two specific design trends influencing the thermal performance of automotive lighting are the use of new aesthetic and high performance bulbs such as amber glass bulbs, red glass bulbs, Silver vision, and the almost required use of aluminized reflectors. While these changes seem to be small, the impact on the lamp's ability to pass required heat testing, as well as the lamp's field performance, can be changed significantly.

The intent of this document is to provide predictive and experimental data that quantify the impact of atypical bulbs (specifically the amber, red, and silver bulbs) as well as the impact of aluminized (or chromed) reflectors on lamp temperatures. Much of the data provided is obtained using computational fluid dynamics. This data will be correlated with the experimental data where possible. An explanation of why these changes significantly impact lighting will also be provided.