Jens Christoffersen

Investigating the use of an adjustment task to set the preferred illuminance in a workplace environment

An experiment was carried out to examine user preferences for light level using the method of adjustment. The study sought preferred illuminances under lighting from fluorescent lamps of different correlated colour temperature. It was hypothesised that the preferred illuminance would be influenced by variables inherent in the experimental design including the available stimulus range, the anchor (initial setting before adjustment) and adaptation time before onset of adjustment action. The experiment included three different stimulus ranges (21–482 lux, 38–906 lux and 72–1307 lux) and these lead to significantly different preferred illuminances (337 lux, 523 lux and 645 lux, respectively). The experimental results confirmed that stimulus range and anchor have significant effects on the outcome of the adjustment task, confirming the importance of considering and reporting these variables when determining user preference with this method.

Simulation of the Non-Visual Effects of Daylight

The daylight design of building spaces for non-visual effects could have major implications for healthcare and residential buildings where occupants can remain in fixed positions for extended periods. This poster describes the formulation and application of a simulation model to predict the cumulative magnitude of non-visual effects due to daylight in buildings.