Light enables us to see and perceive our environment but it also initiates effects beyond vision, such as alertness. Literature describes that at least six factors are relevant for initiating effects beyond vision. The exact relationship between these factors and alertness is not yet fully understood. In the current field study, personal lighting conditions of 62 Dutch office workers (aged 49.7 ± 11.4 years) were continuously measured and simultaneously self-reported activities and locations during the day were gathered via diaries. Each office worker participated 10 working days in spring 2017. Personal lighting conditions were interpreted based on four of the six factors (light quantity, spectrum, timing, and duration of light exposure). Large individual differences were found for the daily luminous exposures, illuminances, correlated colour temperatures, and irradiances measured with the blue sensor area of the dosimeter. The average illuminance (over all participants and all days) over the course of the day peaked three times. The analysis of the duration of light exposure demonstrated that the participants were on average only exposed to an illuminance above 1000 lx for 72 minutes per day. The interpretation of personal lighting conditions based on the four factors provides essential information since all of these factors may be relevant for initiating effects beyond vision. The findings in the current paper give first in-depth insight in the possibilities to interpret personal lighting conditions of office workers.
MULTIFILE
Health symptoms may be influenced, supported, or even controlled via a lighting control system which includes personal lighting conditions and personal factors (health characteristics). In order to be effective, this lighting control system requires both continuous information on the lighting and health conditions at the individual level. A new practical method to determine these continuous personal lighting conditions has been developed: location-bound estimations (LBE). This method was validated in the field in two case studies; comparisons were made between the LBE and location-bound measurements (LBM) in case study 1 and between the LBE and person-bound measurements (PBM) in case study 2. Overall, the relative deviation between the LBE and LBM was less than 15%, whereas the relative deviation between the LBE and PBM was 32.9% in the best-case situation. The relative deviation depends on inaccuracies in both methods (i.e., LBE and PBM) and needs further research. Adding more input parameters to the predictive model (LBE) will improve the accuracy of the LBE. The proposed first approach of the LBE is not without limitations; however, it is expected that this practical method will be a pragmatic approach of inserting personal lighting conditions into lighting control systems.
DOCUMENT
Lighting accounts for a significant amount of electrical energy consumption in office buildings, up to 45% of the total consumed. This energy consumption can be reduced by as much as 60% through an occupant-dependent lighting control strategy. With particular focus on open-plan offices, where the application of this strategy is more challenging to apply due to differences in individual occupancy patterns, this paper covers (1) to which extent individual occupancy-based lighting control has been tested, (2) developed, and (3) evaluated. Search terms were defined with use of three categories, namely ‘occupancy patterns’, ‘lighting control strategy’, and ‘office’. Relevant articles were selected by a structured search through key online scientific databases and journals. The 24 studies identified as eligible were evaluated on six criteria: (1) study characteristics, (2) office characteristics, (3) lighting system characteristics, (4) lighting control design, (5) post-occupancy evaluation, and (6) conclusions, and this was used to answer the research questions. It was concluded that the strategy has not been tested yet with field studies in open-plan offices, but that it needs further development before it can be applied in these type of offices. Although lighting currently tends to be controlled at workspace level, many aspects of the strategy can be further developed; there is potential to further increase energy savings on lighting within open-plan office spaces. Individual occupancy-based lighting control requires further validation, focussing on the factors influencing its energy savings, on its cost effectiveness, and on its acceptability for users.
DOCUMENT
In summer 2020, part of a quay wall in Amsterdam collapsed, and in 2010, construction for a parking lot in Amsterdam was hindered by old sewage lines. New sustainable electric systems are being built on top of the foundations of old windmills, in places where industry thrived in the 19th century. All these examples have one point in common: They involve largely unknown and invisible historic underground structures in a densely built historic city. We argue that truly circular building practices in old cities require smart interfaces that allow the circular use of data from the past when planning the future. The continuous use and reuse of the same plots of land stands in stark contrast with the discontinuity and dispersed nature of project-oriented information. Construction and data technology improves, but information about the past is incomplete. We have to break through the lack of historic continuity of data to make building practices truly circular. Future-oriented construction in Amsterdam requires historic knowledge and continuous documentation of interventions and findings over time. A web portal will bring together a range of diverse public and private, professional and citizen stakeholders, each with their own interests and needs. Two creative industry stakeholders, Yume interactive (Yume) and publisher NAI010, come together to work with a major engineering office (Witteveen+Bos), the AMS Institute, the office of Engineering of the Municipality of Amsterdam, UNESCO NL and two faculties of Delft University of Technology (Architecture and Computer Science) to inventorize historic datasets on the Amsterdam underground. The team will connect all the relevant stakeholders to develop a pilot methodology and a web portal connecting historic data sets for use in contemporary and future design. A book publication will document the process and outcomes, highlighting the need for circular practices that tie past, present and future.
