U.S. Department of Energy - Energy Efficiency and Renewable Energy

Building Technologies Office – R&D Projects

OSRAM SYLVANIA Demonstrates 1,439-Lumen Downlight with Efficacy of 82 lm/W

Photo of an LED: a bright phosphor-coated disk atop a circuit board

LED source from OSRAM SYLVANIA downlight luminaire with light output of 1,439 lumens.

OSRAM SYLVANIA researchers have demonstrated a downlight luminaire that achieves 1,439 lumens at an efficacy of 82 lm/W in steady-state operation. These results exceed the project goals of achieving 1,300 lumens and 70 lm/W at a CCT of 3500K and CRI of 80. Improvements in LED chips, phosphors, optics, electronics, and thermal management at OSRAM all contributed to the higher-than-projected luminaire performance.

The OSRAM SYLVANIA downlight is based on remote-phosphor technology. The light engine consists of a compact array of blue LEDs on a circuit board, covered by a phosphor-coated disk. The phosphor coating on the disk converts the blue light into a warm white light. The fact that there's a space between the disk and the LED helps in thermal management, keeping the device cooler than if the phosphor were stacked or painted directly on the LED. It also keeps the phosphor itself cooler, which expands the range of suitable phosphors to include those whose performance declines at high temperatures.

Another team of OSRAM SYLVANIA researchers is working to overcome the challenges of small-form factor and high lumens output required to create a successful LED replacement for conventional halogen reflector lamps. Midway through the two-year project, the team has demonstrated a small LED light source that achieves 350 lumens at an efficacy of 80 lm/W. The ultimate goal is 500 lumens with an efficacy of 100 lm/W.