Evaluating Occupant Light Exposure and Usage Patterns in an Inpatient Behavioral Health Unit.

OBJECTIVE: To (1) evaluate the use case for tunable lighting in inpatient behavioral health, (2) describe differences in staff lighting exposures between static and tunable lighting conditions using wearable sensors, and (3) document occupant lighting control usage patterns. BACKGROUND: Tunable lighting fixtures can vary the amount of light and spectral content, so have been offered as a way to address light and health considerations. Before we can understand potential health benefits of tunable lighting, it is helpful to understand how occupant exposures under tunable lighting differ from those under more traditional lighting systems. METHODS: Tunable lighting benefits and challenges for inpatient behavioral health were carefully detailed during design. Light exposure measurements were recorded at an old site with static fluorescent lighting and a new site with tunable light-emitting diode (LED) lighting. Behavioral health inpatient unit staff participants voluntarily wore a light measurement device to estimate light exposure. At the new site, controls usage data were recorded each time a button was pressed on a lighting control station. RESULTS: While general observations can be made about the data between sites, there is notable variation at both sites depending on the day and hour. Button press data revealed that occupants used the full capability of the tunable lighting system to support different activities and needs. CONCLUSION: Understanding the relationship between occupant well-being and light requires a holistic research approach including thoughtful design accounting for real-world constraints, detailed measurement of light exposure, and understanding how occupants interact and make use of new technology.