Application of pre-programmed lighting control scenarios: A mixed-methods pilot study in Swedish residential environments

Everyday light exposure plays a vital role in circadian entrainment, especially during twilight. Electric lighting can supplement daylight anytime, enabling unlimited human activity; hence, many struggle to combine a healthy sleep regime with social constraints. Dusk/dawn simulators have been developed to compensate for the lack of twilight exposure and are typically applied in residential environments, where people usually sleep. Innovations in tuneable lighting control enable home-integrated dusk/dawn simulation, but it is essential to understand their performance and acceptance in real-life situations. A pilot field study was executed in 14 Swedish apartments and tested 3 lighting control scenarios for effects on behaviour, well-being and sleep patterns during the winter. Data were collected using wearable actigraphy, weekly surveys and interviews. The light intervention influenced wake- and bedtimes and contributed to slightly more consistent sleep schedules. Subjective responses emphasised that the dawn simulation assisted in a calm and peaceful wake-up, providing extra time for morning activities. The dusk simulation was a reminder to go to bed, but not all participants appreciated the light quality. Satisfaction and acceptance of the pre-programmed dusk/dawn control system were very high, provided there would be increased control for the residents.