Exploring the impact of external shading system on cognitive task performance, alertness and visual comfort in a daylit workplace environment

The authors examined the effect of external shading system on cognitive performance, alertness and visual comfort of visual display terminal (VDT) users under two realistic office lighting settings in this study. Daylight was the source of illumination being considered as the most significant and preferred one. A total of 26 participants performed visual and cognitive demanding tasks as well as providing subjective alertness, performance and visual evaluations in a full-scale mock-up VDT workstation. Two trials (with and without shading system) were executed during one experimental session. Results revealed that the use of a shading system improves the performance of a user on colour-naming task requiring sustained attention, while no differential effects were observed on tasks involving other cognitive skills such as search velocity and vigilance. Within-subject performance differences were more pronounced during morning hours. Higher performance was reported in some cognitive tests when the subjective sensation of visual discomfort was lower

A Methodology for daylight optimisation of high-rise buildings in the dense urban district using overhang length and glazing type variables with surrogate modelling

Urbanization and population growth lead to the construction of higher buildings in the 21st century. This causes an increment on energy consumption as the amount of constructed floor areas is rising steadily. Integrating daylight performance in building design supports reducing the energy consumption and satisfying occupants' comfort. This study presents a methodology to optimise the daylight performance of a high-rise building located in a dense urban district. The purpose is to deal with optimisation problems by dividing the high-rise building into five zones from the ground level to the sky level, to achieve better daylight performance. Therefore, the study covers five optimization problems. Overhang length and glazing type are considered to optimise spatial Daylight Autonomy (sDA) and Annual Sunlight Exposure (ASE). A total of 500 samples in each zone are collected to develop surrogate models. A self-adaptive differential evolution algorithm is used to obtain near-optimal results for each zone. The developed surrogate models can estimate the metrics with minimum 98.25% R2 which is calculated from neural network prediction and Diva simulations. In the case study, the proposed methodology improves daylight performance of the high-rise building, decreasing ASE by approx. 27.6% and increasing the sDA values by around 88.2% in the dense urban district. - Published under licence by IOP Publishing Ltd.We would like to thank Cemre Cubukcuoglu for the collaborative work while implementing the optimisation algorithm. M. Fatih Tasgetiren, who is partially supported by the National Natural Science Foundation of China (Grant No. 51435009), acknowledges the HUST project in Wuhan.Scopu

Perception of Light in Museum Environments: Comparison between Real-Life and Virtual Visual Experiences

Alternative environments to real-life have been in recent demand in regard to lighting design and in museums. In this study, the effectiveness of the perception of the museum space in simulations or virtual-based environments is studied. Answers to a questionnaire regarding lighting in four different visual experiences are compared: Real-life, virtual-video-based, virtual-photo-based and virtual-render-based. A total of 117 participants were divided into four visual experience groups. Each group answered the same lighting related questions for four exhibition halls in the Natural History Museum of the University of Pisa (Italy), which is housed in the Monumental Charterhouse of Calci. The answers were analyzed using ANOVA and a T-test. The results show that virtual experiences can be acceptable alternatives to real-life experience as the answers were indifferent in more than half of the criteria, and no criterion was affected significantly by experience, regardless of the hall’s characteristics. However, it was found that the hall’s characteristics also had an impact on the perception of the criteria in different experiences. Controlled artificial lighting or uniformly distributed lighting (full day or artificial light) were found to be more indifferent to the experience

Analysis of the relationship between daylight illuminance and cognitive, affective and physiological changes in visual display terminal workers

This study explored the impact of daylight illuminance on cognitive load during visual display terminal use by means of various physiological, performance and subjective measures. Repeated-measures design was adopted to identify the impact of variations in daylight levels that were manipulated through the shading system configurations (shading-on; shading-off). A total of 30 subjects performed visual and cognitive demanding tests. Performance measures were supported by subjective data and eye-related measures during the experimental analysis. Results revealed that the use of a shading system had positive impact on sustained attention. Concerning ocular measures, percentage of eye closure values showed opposite tendencies among vigilance and sustained attention demanding tests. Eye aspect ratio-max and blink duration were significantly correlated with reported glare sensation. In all tests, eye aspect ratio-max was found significantly higher in lower illuminances. Search velocity was significantly correlated with ocular variables in higher illuminances whereas sustained attention showed an opposite trend. This, initially, explains that even slight differences in daylight illuminance might have distinctive effects on the relationship between different groups of assessment variables while measuring cognitive load. Secondly, it proves the significance of carrying out sensitive experiments in terms of both light levels and test characteristics. Practical application: The findings of this study could suggest that a practical application, the use of a shading device, might deliver an efficient solution on such a multifaceted question about the potential effects of luminous environment on the evaluation of cognitive load. Work environments might be considered as cognitively efficient if only the harmony of less mental effort, more satisfaction and less health problems exist, which together ultimately deliver higher work performance. In real-world work environments, application of such shading devices involves advantages not only for avoiding excessive daylight exposure or optimizing energy consumption, but also facilitating cognitive, affective and physiological processes of individuals

Application of climate-based daylight simulation to assess lighting conditions of space and artworks in historical buildings: the case study of cetacean gallery of the Monumental Charterhouse of Calci

Exhibits are often displayed in spaces originally not designed to be museums. Thus, is common for those spaces to fail adequate lighting display conditions, both in terms of the artworks’ conservation and visitors’ comfort. In order to objectively assess if an exhibition meets the required standards it is necessary to establish a proper evaluation method. This work proposes a novel procedure relying on climate-based data and dynamic daylight metrics. The procedure, that considers both artworks’ and visitors’ needs, can provide museum curators with scientific, repeatable data. These data can help them screen out potential interventions until the most adequate is found. The main advantages of the new approach are that, if properly validated, the simulations can substitute annual measurement campaigns (thus leading to time and costs savings), and the results are very reliable (thanks to the use of climatic data specific for the site in exam) and that the effectiveness of potential interventions can be predicted simulating as many sceneries as needed. The novel procedure can be applied to assess the exhibits’ display conditions in historic building whenever daylight is the main light source. The validity of the procedure is demonstrated through its application on a case study: the Cetacean Gallery of the Monumental Charterhouse of Calci, near Pisa. The outcome of the assessment demonstrated that the Gallery is over-lit and the exhibits are being damaged, for this reason four potential interventions have been analysed and compared. The accuracy of the simulations was validated through a comparison with on-site measurements

Assessing museums’ daylighting adequacy without annual measurement campaign: Dataset of a confrontation between measured and simulated illuminance values inside the Cetacean Gallery of the Charterhouse of Calci

Lighting Cultural Heritage is a complex task: light is necessary for the act of seeing, it can even enhance the visual experience [1,2], in addition proper lighting can significantly cut down energy consumptions [3], but on the same time it has detrimental effects on exhibits, especially daylight. In order to safeguard the exhibits from damages, national and international standards provide specific recommendations for exhibits’ exposure, based on their photosensitivity category. These recommendations are the annual luminous exposure(LO) and the Maximum Illuminance Level (Emax), museums’ curators have to verify that the display lighting conditions comply with the standards. Historical buildings are often converted into museums but, as their original purpose was different, the lighting conditions are often inadequate (e.g. too much uncontrolled daylight), therefore the lighting conditions’ adequacy of the space should be assessed [4]. As the name suggest the annual luminous exposure requires an annual monitoring campaign, unfortunately it often happens that exhibits have been exposed incorrectly for prolonged periods, and therefore it is very important to evaluate the need of a fast intervention. In this casuistry a prolonged measurement campaign is not acceptable. Simulations can help running a great number of analysis while reducing the length and expenses of a measurements campaign, however their previsions must be validated. This paper provides the data acquired through measurements and simulations inside the Cetacean Gallery of the Monumental Charterhouse of Calci, near Pisa (Tuscany Region, Italy). The data comprehends horizontal and vertical illuminance measurements, recorded on December the 6th, and simulations run in Grasshopper with the plugins Honeybee+ and Ladybug. The data are related to the research article entitled “Application of climate-based daylight simulation to assess lighting conditions of space and artworks in historical buildings: the case study of Cetacean Gallery of the Monumental Charterhouse of Calci”, published on the Journal of Cultural Heritage [5]

Dataset of virtual and real-life visual experiences inside a museum: survey on visual perception with objective and subjective measures

Occupants’ perception of a space depends on their experience [1–3]. Four kinds of visiting experiences were carried out inside the Natural History Museum of the University of Pisa [4]. The museum is housed, together with the National Museum of the Charterhouse [5], inside the Monumental Charterhouse of Calci, near Pisa. Four of the permanent exhibition halls of the Museum were selected for the survey: Historical Gallery, Mammal's Hall, Ungulates’ Gallery and Cetaceans’ Gallery. A total of 117 participants were divided into four groups depending on their visiting experience: real-life, or virtual based respectively on videos, photos or computer-generated photorealistic images (renders). Experiences are compared. The comparison comprehends objective data (measured illuminance levels) and subjective data (questionnaire outcomes on the perception of the space). The illuminance levels were measured using a photoradiometer: datalogger Delta Ohm HD2102.2 equipped with LP 471 PHOT probe. The probe was placed 1.20 m above floor level, and it was set to measure vertical illuminance at 10 seconds intervals. To evaluate participants’ perception of the space questionnaires were used. The presented data refer to the article: “Perception of light in museum environments: comparison between real-life and virtual visual experiences” [1]. This kind of data provides a base to assess if virtual kinds of experience can be implemented in museum environments as an alternative to the real-life experience, and to understand if such an implementation is detrimental or not in terms of participants’ perception of the space. Virtual experiences can be particularly useful for spreading culture, making it accessible even in presence of moving restrictions for people, such as those in force today due to the SARS-CoV-2 emergency