Lighting-on-Demand: Balancing Occupant Needs and Energy Savings

ABSTRACT 

Lighting on demand (LOD) is a high-resolution energy-efficient lighting control technique that dynamically adjusts the lights in a space according to its occupancy. It controls the lights in the space individually such that the area that receives a higher light level is determined by the location of the occupant(s) and, in some cases, by their tasks. In our LOD system, the controls adjust the individual lights above and around the occupant to track him or her while traversing a circulation space. We developed three scenarios with different combinations of light levels in the occupancy and background areas. We built a test bed, developed an occupancy algorithm, and conducted a usability test to demonstrate the acceptability of the LOD system to people walking in the circulation space by asking them to evaluate the conditions they experienced and measuring their walking time. Our test results suggest that in the case of individual occupants walking in a circulation space, the LOD concept is generally acceptable, but there are limits to the dimming potential both for the occupancy area and the background area. Satisfaction seems to be more strongly related to the occupancy area, but walking speed depends on the background level toward which one walks.

KEYWORDS:

• Energy savings
• LED
• lighting control

Acknowledgments

The authors thank Trevor Nightingale (HPB Program Lead) and Guy Newsham for their support and Lorne Whitehead (University of British Columbia) for his original suggestion of investigating LOD.

Funding

This report is a product of the National Research Council Canada project Solid-State Lighting: Enhancing Energy Efficiency and Ensuring Market Acceptance, which is part of the High-Performance Buildings Program. Financial support was provided by the EcoEnergy Innovation Initiative (managed by Natural Resources Canada), Natural Resources Canada–Office of Energy Efficiency, the Independent Electricity System Operator Conservation Fund, and the National Research Council of Canada.

Additional information

Funding

This report is a product of the National Research Council Canada project Solid-State Lighting: Enhancing Energy Efficiency and Ensuring Market Acceptance, which is part of the High-Performance Buildings Program. Financial support was provided by the EcoEnergy Innovation Initiative (managed by Natural Resources Canada), Natural Resources Canada–Office of Energy Efficiency, the Independent Electricity System Operator Conservation Fund, and the National Research Council of Canada.