Search results for " daylight"
showing 10 items of 17 documents
A Survey on Daylighting Education in Italian Universities : Knowledge of Standards, Metrics and Simulation Tools
2021
Daylighting is a strategic topic to achieve sustainable buildings, so it is more and more imperative that it is implemented in architecture curricula to prepare a new generation of daylighting-oriented practitioners. In this frame, the DAYKE project (Daylight Knowledge in Europe) was set up to explore the level of knowledge about daylighting among European professionals and students. DAYKE-Europe was replicated as DAYKE-Italy to study the knowledge of daylight standards, metrics and software among Italian architecture students, and to compare it to that observed within DAYKE-Europe. A sample of 542 questionnaires were collected in five universities. Primary outcomes were: (i) a general low …
Assessment of the Entropy of Spatial and Time Distributions of Rooms Daylighting: A Possible Tool for a Sustainable Design
2015
The indoor visual comfort of subjects faced with indoor ambient lighting varies with the position of the subject and is not constant over time. Average performance indexes, such as the mean value of Daylight Factor and Daylight Autonomy, are commonly used to analyse lighting distribution. These indexes, however, don’t properly take into account either the spatial or the time distribution of values affecting the non-uniformity of environmental lighting. Indeed, these are limited to the definition of a mean value or to the assessment of time availability of daylighting. This paper examines spatial and temporal non-uniformities in indoor lighting as possible causes of discomfort for occupants.…
A set of indices to assess the real performance of daylight-linked control systems
2017
Abstract The installation of Building Automation Control Systems (BACs) in general is an effective action to achieve relevant energy savings. Commercial BACs, installed in residential or small offices, often include functions of lighting control, acting as Daylight-Linked Control Systems (DLCSs). Nevertheless, because system performance is strictly dependent on different parameters, BAC’s hardware and software configuration and as well as an inaccurate commissioning do not always allow a perfect execution of the desired tasks; therefore, the system could not work as expected. Moreover, it is well known that energy saving potential is specifically related to the variability of the light envi…
Glass Surfaces for Benefits of Daylight in Social Housing
2017
Internal environment and appropriate natural lighting of the building interior largely affects the health status and course of treatment of patients with psychiatric diagnoses such as depression, Alzheimer and disorder of functions. In particolar, this paper aims to show how smart glass surfaces, allowing the entry of natural lighting, can better support therapeutic process. It is important to elaborate knowledge for optimized lighting conditions in different healthy populations as well as in patients suffering from visual impairments and circadian rhythm disorders. To contribute to the development of new technologies about smart glass surfaces related to various aspects of light conditions…
Questionnaires and simulations to assess daylighting in Italian university classrooms for IEQ and energy issues
2021
Abstract Results from the DAYKE-Italy project are presented. An investigation on daylighting in eight classrooms in five Italian universities was carried out through a combined approach: an ad-hoc survey administered to students to investigate how they perceive daylight in classroom, and numerical simulations (DIVA + ALFA) to calculate a set of objective metrics (daylight, circadian, and energy-related). A sample of 542 questionnaires was collected through two sessions and the subjective judgments were correlated to objective metrics. Results from descriptive and statistical analyses showed: (i) the correlation was significant for all daylight metrics: among them, average daylight factor an…
Empirical BAC factors method application to two real case studies in South Italy
2021
Abstract The application of Building Automation and Control (BAC) systems has many advantages. One of these is the reduction of the end-user electricity consumption and, if applied to lighting systems, the achievement of well-acknowledged benefits from daylight, such as productivity, health, visual comfort and well-being. Concerning the first aspect, the international Standard EN 15232 proposes the so-called BAC Factors (BF) method to assess the impact of BAC systems on the final energy consumption. The method provides a simplified estimation of the energy savings due to automation in buildings and questions arise on its applicability in some situations. For this reason, the authors have ca…
Performance Analysis of a Prototype High‐Concentration Photovoltaic System Coupled to Silica Optical Fibers
2021
High-concentration photovoltaic (HCPV) systems are one of the most promising technologies for the generation of renewable energy with high-conversion efficiency. Their development is still at an early stage, but the possibility of integrating high-concentration systems into buildings offers new opportunities to achieve the net-zero-energy building goal. Herein, the optical and energetic performance of a hybrid daylighting−HCPV prototype based on pure- or doped-silica optical fibers (OFs) to guide 2000× concentrated sunlight inside the buildings is evaluated. There, the light can either be used to illuminate interior spaces or projected on solar cells to generate electricity. The system equi…
Ultraviolet-visible light-induced solarisation in silica-based optical fibres for indoor solar applications
2021
Abstract The transmission performances of pure- and doped-silica (a-SiO2) optical fibres are compared during the exposure to a high-power broadband light source approximating the solar spectrum. From the Gaussian decomposition of the attenuation spectra, we found that Al- and P-doped fibres show a fast solarisation effect which leads to transmission degradation in the ultraviolet-visible range. Similarly, Ge-doped fibres undergo photoinduced colour-centre formation which, however, does not prevent visible-light propagation. One of the two tested pure-silica fibres results completely unaffected by light exposure whereas the other shows an absorption band probably due to the presence of chlor…
Effects Of Variation Of The Color Characteristics Of Lighting Sources By The Environmental Context
2012
Over recent years the importance of using daylight in indoor environments to achieve reductions of energy consumption was largely discussed, but the use of daylight is even more important because of its effects on human beings. Daylight has a more uniform spectral distribution than the artificial sources (especially discharge lamps) and consequently it allows a better color perception; moreover it changes during the day both in intensity and spectral power distribution (SPD). For all these reasons, daylight ensures a high comfort in carrying out all the human activities and is also important to the circadian rhythm regulation; therefore it results necessary to evaluate the entrance of natur…
Calculation of Energy Performance Indices of Daylight Linked Control Systems by Monitored Data
2017
The actual performances of Building Automation systems are often lower than the ideal ones. In order to investigate the actual performance of a Building Automation system for lighting control, a large stock of collected data, including indoor illuminance and absorbed electric power, have been presented and analysed in this paper. The measures have been taken during one year, in a laboratory located at the University of Palermo, where different lighting control systems, produced by two different manufacture companies, have been installed. As demonstrated in literature, many factors affecting energy savings’ evaluation in lighting control systems are the position and the typology of the senso…