M.P.J. Aarts

Dynamic lighting systems in psychogeriatric care facilities in the Netherlands : a quantitative and qualitative analysis of stakeholders’ responses and applied technology

Long-term care facilities are currently installing dynamic lighting systems with the aim to improve the well-being and behaviour of residents with dementia. The aim of this study was to investigate the implementation of dynamic lighting systems from the perspective of stakeholders and the performance of the technology. Therefore, a questionnaire survey was conducted with the management and care professionals of six care facilities. Moreover, light measurements were conducted in order to describe the exposure of residents to lighting. The results showed that the main reason for purchasing dynamic lighting systems lied in the assumption that the well-being and day/night rhythmicity of residents could be improved. The majority of care professionals were not aware of the reasons why dynamic lighting systems were installed. Despite positive subjective ratings of the dynamic lighting systems, no data were collected by the organizations to evaluate the effectiveness of the lighting. Although the care professionals stated that they did not see any large positive effects of the dynamic lighting systems on the residents and their own work situation, the majority appreciated the dynamic lighting systems more than the old situation. The light values measured in the care facilities did not exceed the minimum threshold values reported in the literature. Therefore, it seems illogical that the dynamic lighting systems installed in the researched care facilities will have any positive health effects.

Systematic review on the interaction between office light conditions and occupational health: Elucidating gaps and methodological issues:

Purpose The International Commission on Illumination (CIE) recommends researchers to investigate a wide variety of behavioural and health outcomes. However, researchers often investigate only a part of occupational health (OH) in relation to light. A literature study (2002–2017) regarding the relationship between office lighting conditions and OH was performed to identify gaps and methodological issues. Method The OH outcomes investigated in this paper were grouped according to the International Classification of Diseases and analysed per category: physical and physiological health, mental health, eye health, sleep parameters and visual comfort. Results Findings from the literature study (20 eligible papers) showed that all OH aspects were mostly but not exclusively measured subjectively. Furthermore, most studies investigated only a fraction of office lighting parameters and OH aspects. Conclusions It seems that Correlated Colour Temperature (CCT) and illuminance mainly correlate with OH. However, this may also be explained by gaps and methodological issues in studies described in eligible papers. Based on the literature study, an overview was composed elucidating gaps and methodological issues of office lighting and OH studies. It can be used to design and target the purpose of light and health research.

Personal Lighting Conditions to Obtain More Evidence in Light Effect Studies

Research demonstrated a large variety regarding effects of light (e.g. health, performance, or comfort effects). Since human health is related to each individual separately, the lighting conditions around these individuals should be analysed individually as well. This paper provides, based on a literature study, an overview identifying the currently used methodologies for measuring lighting conditions in light effect studies. 22 eligible articles were analysed and this resulted in two overview tables regarding the light measurement methodologies. In 70% of the papers, no measurement details were reported. In addition, light measurements were often averaged over time (in 84% of the papers) or location level (in 32% of the papers) whereas it is recommended to use continuous personal lighting conditions when light effects are being investigated. Conclusions drawn in light effect studies based on personal lighting conditions may be more trusting and valuable to be used as input for an effect-driven lighting control system.

Local Lighting Control in Open-Plan Offices: The Influence of Office Lay-Out

Highly granular lighting control involves switching on and off luminaires based on individual occupancy. The resulting high frequency of lighting changes can distract the office workers and negatively impact their work performance. In a cubicle office, this might be less of an issue than in an office without partitions, as users do not have an overview over the space here. We tested this control strategy in both office types and compared the results to determine the influence of office lay-out on the amount and acceptability of distractions that it poses. Our results indicated the opposite: occupants in the cubicle office were more often distracted and rated the distractions as less acceptable than in the bullpen office. As the job function types varied and the bullpen was consequently more dynamic, it seems that the type of work environment is of larger influence on users’ satisfaction with local lighting control. However, more research is required to confirm this finding.

An unobtrusive practical method to derive individual's lighting conditions in office environments

The benefits of light in offices beyond enabling visual tasks have been demonstrated in former studies. Light positively influences outcome measures such as humans health, wellbeing, visual comfort, motivation, and environmental satisfaction. In order to measure the effects of light on the individual outcome measures, it is of high importance to correctly measure lighting conditions in realistic environments per individual. This paper describes a six-step practical method to derive lighting conditions for all work places in an office building based on continuous reference measurements. The method proposed in this paper allows the shift from laboratory studies to field studies so that the real effect of office lighting can be investigated simultaneously while the office worker is doing his or her real work.