REVIEW ON HUMAN-CENTRIC LIGHTING FOCUSING ON SMART SOLID-STATE LIGHTING AND SWITCHABLE GLAZING

Hydroponics is the latest innovation in farming where plants are grown in the absence of soil. In India adoption rate of hydroponics is estimated 13 – 15 % annually. In this context present study was conducted to analyze the morphological characteristics of cucumber plant in Dutch Bucket Hydroponic system. Moreover, comparative evaluation of morphological characteristics of cucumber plants were carried out under natural light as well as artificial light emitting diode (LED). The experiment was carried out in the Naturally Ventilated Polyhouse (NVPH) and in the laboratory (as an indoor practice) in the campus of Dadasaheb Mokashi Collage of Agricultural Engineering and Technology Rajmachi, Karad, Maharashtra, India. Cucumber (Cucumis sativus) HY shiny variety was grown in both the environments to evaluate different morphological characteristics such as average leaf count, leaf area, stem diameter, plant height and root length. Dutch bucket system of 10 buckets (each having capacity of 11 liters) was installed each in natural and artificial light source. Cucumber plants were grown in both environment for months June- July 2024. From the present experiment it was observed that, most of the selected parameters were found more satisfactory in artificial light as compared to natural light. Before the flowering stage, average leaf count, average leaf area, average plant height, and average root length was observed approximately 26, 123.15 cm2, 154 cm, 30.1 cm for artificial light and 22, 56.07 cm2, 110 cm, 25.3 cm for natural light, respectively. The average stem diameter was observed almost similar in both the systems and it was about 1.1 cm. Therefore, from this study it was envisaged that overall average leaf count, average leaf area, average plant height and average root length was improved in artificial light by 18%, 54%, 28%, and 25%, respectively over natural light.

Natural light adaptive context lighting system that provides a lighting environment tailored to the User's objectives.

Indoor landscaping is an environmentally friendly approach that enriches the environment and fosters productivity and comfort for occupants. The practice of incorporating plants into interior spaces requires meticulous care to ensure healthy growth and prolong the benefits of interior greening. This study explores the impact of natural and artificial light, represented by fluorescent lighting on the growth and physiological responses of Codiaeum variegatum and Ardisia japonica. A natural light chamber and an artificial light chamber of identical dimensions were constructed to compare the plants’ physiological responses under consistent temperature, humidity, and illuminance conditions. The results indicate that Codiaeum variegatum and Ardisia japonica exhibited higher chlorophyll content and photosynthetic rates under natural light conditions compared to fluorescent lighting. Furthermore, the study found that natural light offers a rich spectral distribution across various wavelengths, providing an advantage for plant growth. Although direct comparisons between natural and artificial light environments are inherently challenging due to the distinct characteristics of each light source, the study emphasizes the importance of considering the rich spectral distribution of natural light when designing artificial lighting systems for optimal plant growth. In conclusion, understanding the effects of natural and artificial light on indoor plants is crucial to supporting plant growth and creating more effective indoor gardening solutions. Although direct comparisons between natural and artificial light environments are inherently challenging due to the distinct characteristics of each light source, natural light provides a more advantageous environment for growth compared to fluorescent lighting, with Codiaeum variegatum and Ardisia japonica both exhibiting a higher chlorophyll content and photosynthetic rate under natural light conditions.

An integrated solar and artificial light system for internal illumination of photobioreactors

As public buildings, student dormitories must be comfortable as they host most of the students' lives and activities. A space's visual and thermal comfort significantly impacts the occupants' activities and productivity. Indicators for assessing the building comfort level include visual, thermal, and noise comfort in spaces or buildings. This paper presents the results study of the building's visual and thermal comfort measurement and the occupants' perception toward comfort. This paper also presents the comparison between that measurement and the occupants' perceptions. This research employs a mixed-methods approach consisting of qualitative methods (occupants' perception questionnaire) and quantitative methods (field measurements of lighting levels, air temperature, and humidity). Data were collected through questionnaires distributed to dormitory residents and field measurements using an Environmental Meter 4 in 1 to measure natural and artificial lighting levels, air temperature, and humidity. The data obtained were analyzed and then presented in a descriptive format. Based on residents' perceptions, the findings indicate that the overall visual and thermal comfort in the dormitory building falls within a good category. The field measurements on natural lighting, air temperature, and humidity show that the student dormitory building meets the established comfort standards. However, the artificial lighting of staircases and corridors doesn't meet the standards due to many non-functioning lights and low lumen levels. Overall, the lighting, temperature, and humidity conditions in the dormitory building are influenced by building design, orientation, surrounding environment, and occupants' behavior. To enhance comfort and health for residents, improvements in artificial lighting systems, enhancement of natural ventilation, and education on the importance of good air circulation are necessary.

Energy consumption continues to increase and is predicted to increase by up to 30 percent by 2040. Therefore, systematic efforts are needed to reduce energy use, including using natural lighting in lighting systems inside buildings. The object of this study is the library room in the Electrical Engineering Department building, Universitas Andalas, Indonesia, to calculate the potential for energy savings with a lighting automation strategy with dimming control. Measurement of natural light level at three work nodes has been determined for one week as reference data. The shortage of artificial light required, and the electrical energy consumed is calculated by referring to the minimum standards for room lighting intensity. On the basis of each lamp's working hours and power, the potential for energy savings in the lighting system of the object can be determined. This study found that the potential for saving energy consumption for one week at three different nodes was 32.3, 64.2, and 82.8 percent. This study concludes that the maximum value reached 893 lux on Tuesday at 13:00 at node C, and the lowest was 3 lux on Saturday at 15:00 WIB at node A. Node C had an average light intensity of 402.298 lux, and node B had an average of 206.765 lux during the week. In contrast, node A has the lowest lux average, with 87,711 lux in one measurement week. Also, with the combination of natural and artificial light sources with dimming control strategies, the voltage values given to each lamp range from 0 to 180 VAC. Potential savings in energy consumption by combining natural and artificial light with dimming control strategies in the library room with three different nodes (A, B, C) are 32.3, 64.2, and 82.8 percent.

Light plays a very important role in film and television, especially in terms of its impact on character shaping and relationship construction. This paper uses light as a starting point to analyse the effect of natural and artificial light on the portrayal of the characters taking the films Days of Heaven and Whiplash as examples, respectively. Furthermore, it compares the similarities and differences between natural light and artificial light in character modelling and proposes some suggestions on light modelling for practical shooting. The most important role of both natural and artificial light is to illuminate people. As natural light is scattered, it is mostly used as a base to restore a realistic and natural state of life. However, regarding natural light, special moments such as magical hours can be used to create a warm and ambiguous atmosphere. It is also possible to make use of existing shades to create rich light effects. Artificial light is very controllable and can be adjusted in terms of direction, colour temperature, softness, and texture to give different visual effects. The same person can be portrayed in different ways under different lighting.

Solid State Lighting (SSL) technology is a new technology based on light emitting diodes as light sources. This technology due to its several outstanding characteristics such as lower energy consumption, longer lifetime, and higher design flexibility with respect to the conventional lighting technology has become very attractive to both manufacturers and consumers. It is applied in variety of applications such as in-door, out-door, automotive, and agriculture lighting. Like any other new and fast evolving technology, SSL technology reliability requires special attention, and its long lifetime brings extra challenges to this study. This research focuses on reliability of SSL devices electrical driver (SSL driver). In this thesis, a systematic approach to address the reliability of SSL drivers is introduced. There are many design variations for SSL drivers due to the application field criteria. It means SSL driver as one term refers to a wide range of devices. The systematic approach tries to provide guidelines suitable to be applied to different types of SSL drivers. In order to predict the SSL driver's thermal / electrical behavior and consequently to define its lifetime, a multi-physics reliability assessment methodology is introduced.

One fifth of the electricity consumption of Swiss buildings is due to electric lighting. Integrated control of sun shading and artificial lighting can mitigate this demand while maintaining user comfort. However, the drawback of existing building control approaches is that they do not consider one of the main aspects of human-centric lighting: visual comfort. The goal of this doctoral thesis is to develop an integrated energy efficient sun shading and electric lighting control system that incorporates widely accepted visual comfort criteria and privileges daylighting over electric lighting. The first part is dedicated to High Dynamic Range (HDR) vision sensor calibration, programing, validation and preliminary testing. A sensor originally developed by the Centre Suisse d’Electronique et de Microtechnique (CSEM) was photometrically, spectrally and geometrically calibrated and validated with respect to reliable illuminance and multi-point luminance meters. This HDR vision sensor was then equipped with an embedded image processing routine in order to assess ‘on the fly’ discomfort glare indices. It has been demonstrated that the developed device, is able to serve as an enhanced visual comfort feedback sensor in building automation systems. On the other hand, it can be employed to characterize highly glazed facades and workspaces regarding visual comfort and glare risks, as demonstrated in a project in Singapore. Two monitoring campaigns are reported in the second part of this thesis. Firstly, 30 human subjects occupied two identical office rooms of the LESO solar experimental building for 15 afternoons to compare the performance of a fuzzy logic control system incorporating two HDR vision sensors with respect to a ‘best-practice’ controller. Subjective self-reported visual comfort surveys, paper- and computer-based visual tests and monitoring of the electric lighting consumption were carried out simultaneously in both offices. It was shown that the electricity demand of the office with the advanced controller is 32% lower than that of the reference room, while the subjects’ visual performance remained comparable. Secondly, an eight-month data monitoring campaign was carried out in the same building in order to study the ability of a novel control approach to maintain optimal visual and thermal comfort conditions while reducing the energy performance gap of a room as well as its electric lighting demand. The experimental results showed that the advanced controller mitigated the performance gap during the heating season by 72% with regard to standard occupant behavior and by 19% with respect to a best-practice automated system. This system reduced backup heating demand leading to lower CO2 gas emissions. At the same time, visual comfort constraints regarding Daylight Glare Probability (DGP) and workplane horizontal illuminance were respected during work hours. Finally, a self-commissioning integrated controller for Venetian blinds enhanced with a learning module was developed and validated for 22 days in a daylighting testbed at the Fraunhofer Institute for Solar Energy (ISE) in Freiburg, Germany. It has been shown that the visual comfort constraints are respected for 96% of the work hours and that the controller can successfully limit the number of shading movements. The market potential for HDR vision sensors and integrated control platforms has been studied and possible commercialization tracks have been identified.

The problem of creating the safe and the comfortable light environment under the optimal working conditions for preserves the health of the workers and the high level of efficiency are deals in the article. The analysis of last researches and publications shows: in the absence of natural light in the rooms during 90% of the working time and in the measures for compensation of ultraviolet insufficiency the working conditions become harmful (the 1 and 2 degrees). The analyze of the possibility for natural light wind in the new modern construction projects and in the existing buildings and the creation of artificial lighting due to new light sources, taking into account the psychophysiological state of the human body. In order to achieve t his goal, the operating norms of the light environment were analyzed, conset ruous solutions of light openings for light exposure to the work places taking into account the ecoclimatic lighting conditions on the example of the city of Dnipro, the analysis of existing modern artificial lighting systems of the light environment, the effect of illumination on the levels , sources for human health, working capacity and safety. It is determined that the implementation of the project of the new DBN "Natural and artificial lighting" will allow to provide acceptable working conditions at permanent workplaces as a factor of the light environment. The choice of energyefficient design solution for entering the home light in the premises, taking into account the ecoclimatic conditions, will c reate a comfortable light environment in terms of natural light, and artificial lighting of permanent workplaces should not create psychophysiological discomfort and be a source of a harmful production factor.

Spectrometry of biofilms in microhabitats (e.g. rock crevices) is difficult using natural light. An alternative approach was evaluated using a reflectance probe with an artificial light source to measure the abundance and pigment composition of intertidal biofilms in situ. Measurements made by the probe were compared with those made under sunlight. To determine whether the probe could be used to measure amounts of chlorophyll a (chl a, as an index of biomass), reflectance spec- tra (350-1050 nm) were acquired from microalgae grown on sandstone discs. Spectra were acquired under natural light and using the probe (artificial light) with or without an intervening layer of plas- tic. Two chlorophyll indices (a ratio of reflectances at 750 and 672 nm and the Phytobenthos Index) were used to estimate amounts of chl a from the spectra. Strong linear relationships were found between laboratory measures of chl a and both chlorophyll indices (R 2 ranging from 0.85 to 0.94). Spectra of natural intertidal biofilms were used to determine whether there were any differences between spectra measured under natural and artificial light in terms of the shapes of their curves and the wavelengths and heights of absorption peaks caused by photosynthetically active pigments. No differences in shapes of curves were found between spectra measured under natural and artificial light. The wavelength positions of absorption peaks were similar between spectra measured under sunlight and artificial light but there were differences in their height. Taken together, results show that the reflectance probe presented a reliable and rapid method for providing quantitative and qual- itative information about intertidal biofilms in situ.

Organic Materials Degradation in Solid State Lighting Applications

In hyperspectral remote sensing measurements, the spectral effective information extracted under different measurement light source conditions will produce differences, which in turn affects the robustness of the constructed models. Therefore, it is important to study the differences between hyperspectral estimation models under different measurement light source conditions to construct a general hyperspectral model of vegetation parameters under different light source conditions. In this paper, hyperspectral models are constructed from artificial and natural light sources, and the hyperspectral reflectance and the corresponding SPAD values of artificial and natural light sources under winter wheat, corn and tea tree were measured under the same time period and the same light measurement angle and height. The collected data were used to construct models for the four vegetation indices with better results after screening and to explore how to reduce model variability under different measured light source conditions. The results show that the difference between the artificial light source and natural light source models is significant (the coefficient of determination R2 is significantly different between the artificial light source and natural light source models), and the influence of different light sources on the construction of hyperspectral estimation models can be reduced by selecting vegetation indices. The linear regression equation model constructed by NDVI can effectively reduce the influence of different light sources on the construction of SPAD hyperspectral models and make the model more general. This study can provide new ideas and methods to investigate the differences in spectral models under different measurement light sources.

Semarang city in Central Java has natural lighting from sunlight, throughout the year and can be optimized when integrated with artificial lighting. It will be reduce electrical consumption. Research in lecturer’s workspace in Gedung Pusat UPGRIS performs a simulation analysis of natural and artificial lighting and their integration using the Dialux EVO version 9.0. The simulation results of the existing condition of natural lighting is 164 Lux (09.00 AM) and 225 Lux (01.00 PM), while the existing simulation results provide 201 Lux with a power consumption of 1.69 Watt/m2. The results of the integration natural and artificial lighting produce 265 Lux (09.00 AM) and 256 Lux (01.00 PM) with the same electrical consumption of 0.84 Watt / m2. This value shows that the existing simulations of natural, artificial and integrated of them are still less than the SNI 16-7062-2004 standard is 350 Lux. The first retrofitting by changing the type and number of lamps resulted in 393 Lux higher from SNI standard 350 Lux. The simulation produced 556 Lux at 09:00AM and 648 Lux at 01:00PM, veryhigher than SNI standart 350 Lux. Through this retrofitting approach, artificial lighting at night shows minimum standard because no light. The second retrofitting effort is to turn off the lights automatically Lux sensor in the workspace area near the windows the natural lighting is strong enough, the results show that the illumination strength of 402 Lux at 09:00AM and 494 Lux at 01:00PM with low electrical consumption during the day becomes 2.92 Watt/m2.

The paper identified the main aspects of the natural lighting of interior spaces of residential and public buildings, affecting the light forms of education, the quality of light, visual comfort, visual discomfort, uneven illumination, and so on. The quality of architecture as a visual art is mainly evaluated because of visual impressionsthat are possible only in the presence of light. The modern period of development of society is characterized by objective civilized processes of global urbanization, as a result of which architecture itself becomes a cause of a disturbance in the state of balance of the environment for human life and the cause of the ecological crisis. It is known that under the influence of such anthropogenic factors as a decrease in the transparency of the atmosphere due to the growth of cities and industry, insolation resources are changing in residential areas. In the framework of the concept of an urban-ecological approach in the formation of the human environment, the problems of creating a comfortable bioclimatic architecture or ecological buildings that allow the multilateral use of the energy of the Sun are highlighted.Among the factors determining the quality of the environment, an important place is occupied by the natural light environment, which largely depends on the nature of the light climate. Sunlight has a comprehensive impact on all major categories of architecture, including light comfort, durability, expressiveness, and economy. The appropriate level and quality of lighting in rooms and urban areas is an important prerequisite for creating light comfortable living conditions for a person, contributes to his creative activity, increase labor productivity and improve leisure conditions. The parameters of the light environment are one of the main elements that form the microclimate of the premises.In many developed countries, in connection with the expansion of megacities, the issue of not only functional, but also visual aesthetic comfort of the environment is becoming relevant. Creating a light environment that meets the practical, psychological andaesthetic requirements of the people who live in it is one of the most important tasks of an architect. Knowledge of the basic compositional properties of lighting, the ways of its rational use in architecture, and the possession of methodological skillsin architectural design contribute to the successful solution of this problem. Lighting conditions determine the correct perception of the compositional rhythm, the proportions and depth of the premises, plastics and color finishes of the surface.The concept of a light environment includes the integral coordination of the components of natural and artificial lighting, considered in unity and interaction. The progressive reception of integrated (combined) lighting is dictated by social need and is reflected in improving the quality of lighting and in saving resources for the design and construction of buildings and structures.Modern advances in the field of fundamental and natural sciences allow us to improve the methods and means of research and forecasting in the knowledge of the complex interaction of man and the environment. The main task is to optimize the light environment in architecture with the rational use of energy and natural resources.The analysis of scientific works and design practice of architectural firms of Ukraine allowed us to identify a number of unresolved issues (in the aspect of accounting and solving the problem of the comfort of the lighting environment in architecture): 1) black-and-white shaping as a specific tool for architectural composition to achieve plastic expressiveness and as a tool for the architect’s creativity; 2) in the process of developing the facades of buildings for various purposes, the relation to the functional and formative function of light is traced; 3) theeffect of sunlight on interior spaces; 4) the effect of sunlight on residents in high-rise residential buildings. The problem of creating a comfortable lighting environment in European architecture has not been comprehensively considered to date, which served as the basis for analysis and discussion in this work.The comfort of the light environment is lighting, it is the light formation of the interior spaces of architectural objects. The comfort of the lighting environment can satisfy people in the interior according to many requirements, divided into qualitative and quantitative categories.Quantitative categories are determined by the level of necessary illumination. Qualitative categories are determined by the spectral composition of light and its distribution in space.