Luminaire Level Lighting Study

Project Information

Lighting redesigns and retrofits have long provided substantial energy savings. Lighting redesigns often produce higher quality environments than retrofits but typically cost more and require longer project timelines. This pilot study evaluated four Luminaire Level Lighting Control (LLLC) solutions of varied complexity in a one for one (1:1) replacement of existing lighting and compared these against a baseline and a redesign solution for human preference, cost, project duration, and energy. Collected data included: lighting energy use, indoor and outdoor environmental metrics, human factors rating of lighting quality, and interviews with installation contractors.

The study found that total measured lighting energy savings ranged from 70-77% for 1:1 and 63% for the redesign, compared to a fluorescent baseline (LED upgrade included), while estimated annual savings ranged from 70%-75% for 1:1 and 59% for the redesign. Estimated annual savings due to controls ranged from 47%-61% for 1:1 and 49% for the redesign. The cost of the 1:1 LLLC retrofit solutions ranged between one-third to one-half that of the redesign. The human factors analysis generally showed preferable lighting conditions, and did not show statistically significant differences between systems, lending confidence that acceptable satisfaction is expected for similar 1:1 retrofit systems. These findings support the value of rapid retrofits using LLLC 1:1 technology as a cost competitive and scalable alternative to complete lighting redesign. Nonetheless, redesigns with networked lighting controls systems remain valued by users, offer comprehensive modes of system control and energy efficiency.