Towards a Sustainable Indoor Lighting Design: Effects of Artificial Light on the Emotional State of Adolescents in the Classroom

Toward Sustainable Gentle Awakenings and Sleep Inertia Mitigation: A Low-Cost IoT-Based Adaptable Lighting and Temperature Control Approach

In this paper, our design aims to assist in sleep inertia reduction and avoid the startle response and irritation caused by alarm-made unpleasant wakeup stimuli. Thus, we propose an approach that employs a soft and alerting sunrise simulation, conditionally utilizes natural light, and appropriately lowers the bedroom temperature for awakening a sleeper tenderly and gradually to gain full alertness. This approach is inspired by known scientific implications confirming the effectiveness of lights and temperatures on wakefulness. In this regard, we present an economical do-it-yourself digital tech-assisted system for bedroom lighting and temperature control. The system design is based on the smartphone and Internet of Things (IoT) technology. We develop the hardware and software in the system for implementing three IoT-based control tasks. One is the tuning of artificial light brightness using the pulse width modulation technique. Another is the opening of the window curtain using stepper motor control and light detection. The other is the activation of the air-conditioning setting using an infrared remote control and temperature detection. We construct a testbed for conducting experiments. Experimental results demonstrate that the proposed system can execute task requirements satisfactorily. The proposed system is promising for achieving our goal. It embodies features of sustainability.

Improving Visual Comfort and Health through the Design of a Local Shading Device

As people develop higher standards for the beauty of urban architecture, more and more architectural designs are exploring sources of natural lighting, such as glass curtain walls and glass domes. However, the pursuit of architectural design aesthetics introduces glare into buildings, which can be uncomfortable and even dangerous for health. Scholars in related fields have carried out many theoretical studies and design activities based on this problem. In this study, we focus on issues of glare in public buildings, aiming to improve light comfort by solving this problem. First, we propose an improved design strategy based on IDEO design thinking by adding the step of diverging from the design scheme. Second, guided by the results of a questionnaire survey and light environment simulations, we avoided the subjective simplicity of the traditional design process. Third, taking the main library of Shanghai Jiao Tong University as an example, we designed a movable sunshade that could effectively reduce glare effects and improve visual comfort, which improved the light comfort in public buildings. The simulation results show that the proposed design can be useful in buildings to effectively control glare and improve visual comfort and health.

Smart Design of Portable Indoor Shading Device for Visual Comfort—A Case Study of a College Library

With the development of architectural technology, the use of floor-to-ceiling windows has emerged widely. The ensuing problem is that more and more students and office workers are suffering from direct sunlight while working in specific areas. Based on the pain points of the working process, this study designed a portable product for improving visual comfort through field research and environment simulation. It provided a new personalized design for blocking direct sunlight from the working area using a portable and liftable sunshade curtain, allowing the users to control the height and angle of the sunshade curtain through a mobile phone application. It can also adjust itself according to environmental parameters collected by sensors, so as to block sunlight in certain areas. A simulation based on the design features and the light environment of a library is run, proving the model effective in improving these aspects. The study aimed to provide solutions for indoor visual comfort and suggestions for future indoor household designs.

Purpose Adequacy as a Basis for Sustainable Building Design: A Post-Occupancy Evaluation of Higher Education Classrooms

Building design is one of the essential elements to consider for maximizing the sustainability of construction. Prior studies on energy and resource consumption and on indoor environmental quality indicators (IEQs) are increasingly frequent; however, attention has not been focused on design as supporting the function performed within architecture. Educational buildings have specific conditions related to teaching methodologies, including activating students and promoting participation and interaction in the classroom. This manuscript aims to explore whether the social dimension of physical space in educational settings can explain a student’s academic outcome. For this, the Learning Environment and Social Interaction Scale was designed and validated and applied to 796 undergraduate students at the University of Coruña, and multiple linear regression analysis was applied to the academic results. The results display a structure comprising five factors; these include novelties such as the division of conventional IEQs into two groups: the workspace and the classroom environment. In addition, place attachment, the design of the classroom as a facilitator of social interaction, the learning value of social interaction, and the satisfaction of the IEQ demonstrated their influence on the academic result.

Modular system for UV-vis-NIR radiation measurement with wireless communication

Light wavelengths like Ultraviolet (UV) and Near-Infrared Radiation (NIR) are some topics of great interest for research in renewable energy, agriculture, architecture, interior design, and psychology. Due to the light spectrum influence in all these fields, it is necessary to develop instruments that facilitate their remote measurement and storage using Internet of Things technology. In this work, a modular system of sensors for UV-vis-NIR radiation measurement is presented. The system includes six multi-spectral sensors that allow 54 different measures. The acquired data can be sent to the cloud in real-time or stored in a micro SD memory in separate files (per sensor) to facilitate its reading, each data is time-stamped using Unix format, synchronized with a Network Time Protocol (NTP) server. The sensor enclosure was standardized in installation and all of them except the AS7265 have the same size, and were covered with a 1/8" PTFE sheet to take advantage of its diffuser characteristic. Finally, the sensors were mounted on a standard 2020 extruded aluminum guide rail, this rail allows to fix sensors in different distances and arrangements, bringing adaptability to the system.

Development of an Automatic Low-Cost Air Quality Control System: A Radon Application

Air pollution is the fourth-largest overall risk factor for human health worldwide. Ambient air pollution (outdoors) and household air pollution (indoors) cause about 6.5 million premature deaths. The World Health Organization has established that between 3% and 14% of lung cancer cases are due to radon gas, making it the most important cause of lung cancer after smoking. This work presents a fully automated, low-cost indoor air quality control system that can monitor temperature, pressure, humidity, total volatile organic compounds (TOVC), and radon concentration. Using the radon concentration as an air quality measure, we created a prediction algorithm. The system uses those predictions to control a ventilation system automatically. We tested the algorithm for different prediction windows and compared the results with those without the ventilation system in a radon research room. In this room, the radon concentration is high 100% of the time, reaching a level eleven times higher than the recommended limit. The results show that the system can achieve an 86% reduction of the radon concentration, maintaining it low 90% of the time while having the ventilation system on during only 34% of the time. This work demonstrates that we can control air quality using low-cost resources, keeping a household or workplace safe but comfortable.

Indoor Lighting Workplaces

Office work has so far been carried out in company buildings and was largely based on the use of paper on a horizontal surface. Due to multiple reasons, more workers are working in their homes with electronic devices. As a result, both the working environment and personal tools are changing. Since the discovery about 20 years ago of the non-visual ways of light absorption, it was known that apart from the image forming effects (IF) of light from which the criteria for correct lighting have been developed, non-image forming effects (NIF) of light exist. The discovery of NIF has enhanced researcher belief in the importance of daylighting and has raised new criteria to be taken into account for proper interior lighting. Due to all the factors mentioned above, the parameters to be met by a luminaire and its environment for proper lighting of the workstation have been modified and expanded. The rapid advance in the development of new light-emitting diode (LED) luminaires with which the spectral power distribution (SPD) can be practically created opens the door to a genuine technological revolution comparable to the invention of electric lighting around 150 years ago. The authors of this study will review the latest published studies on the importance of light in our lives, IF and NIF effects of light, the parameters which from these effects are suggested to be taken into account for a correct indoor lighting, the regulations in force on indoor lighting workplaces, and proposals to improve indoor lighting and therefore the quality of life of workers.

Indicators Framework for Sustainable Urban Design

Climate change and sustainability have recently been object of study due to the impact on the planet and on human activity of the first and the benefits that could derive from the efficiency of the second. Particularly, urban environments are locations that represent a high percentage of emissions of gases, waste, resources use and so forth. However, they are places where great changes can be made, in an attempt to accomplish the urgent challenge to adapt to current and projected rates of climate change. Research has shown that a fruitful approach to urban sustainability is to describe indicators that measure the effectiveness of current processes of urban infrastructures, analyze areas in need of improvement and measure the effect of any actions taken. The significant feature of this research relies on its global approach, considering both major worldwide used and less widely-spread frameworks and the analysis of the 32 selected tools and guidelines, including over 2000 indicators. The result is a proposed structure of 14 categories and 48 indicators, easily applicable in urban areas, that tries to fulfill basic aspects to obtain a general diagnosis of the sustainable nature of the urban environment, which can serve as support to detect the strongest and weakest areas in terms of their sustainability.

Blue-Light Levels Emitted from Portable Electronic Devices Compared to Sunlight

Over recent years, a technological revolution has taken place in which conventional lighting has been replaced by light emitting diodes (LEDs). Some studies have shown the possibility that blue light from these artificial sources could have deleterious effects on the retina. Considering that people spend a non-negligible time in front of screens from computers and mobile phones, the eyes receive blue light of different intensities depending on the source. Nevertheless, any study about the visual and non-visual effects of blue light must consider precise measurements taken from actual artificial sources. For this reason, we have analyzed the spectral emission of 10 different electronic devices and weighted them according to the hazard caused by blue light to the eyes, comparing the results with solar radiation simulated with a radiative transfer model. The maximum spectral irradiance of the measured electronic devices at 10 cm from the detector was located between 440 nm and 460 nm. The irradiance for blue light hazard ranged from 0.008 to 0.230 Wm−2 depending on the particular characteristics of each electronic device. In contrast, the solar radiances in the same spectral range are larger both under clear and cloudy conditions.

Overheating in Schools: Factors Determining Children’s Perceptions of Overall Comfort Indoors

Climate change is raising the length and intensity of the warm season in the academic year, with a very significant impact on indoor classroom conditions. Increasingly frequent episodes of extreme heat are having an adverse effect on school activities, whose duration may have to be shortened or pace slackened. Fitting facilities with air conditioning does not always solve the problem and may even contribute to discomfort or worsen health conditions, often as a result of insufficient ventilation. Users have traditionally adopted measures to adapt to these situations, particularly in warm climates where mechanical refrigeration is absent or unavailable. Implementation of such measures or of natural ventilation is not always possible or their efficacy is limited in school environments, however. Such constraints, especially in a context where reasonable energy use and operating costs are a primary concern, inform the need to identify the factors that contribute to users’ perceptions of comfort. This study deploys a post-occupancy strategy combined with participatory action to empower occupants as agents actively engaging in their own comfort. It addresses user-identified classroom comfort parameters potentially applicable in the design and layout of thermally suitable spaces meriting occupant acceptance.