Development and Metrological Characterization of a Multi-sensor Device for Indoor Environmental Quality (IEQ) monitoring

Indoor Environmental Quality (IEQ), which affects people's health, comfort, well-being and productivity, combines thermal, visual, acoustic and air quality conditions. This work deals with design, development and metrological characterization of a low-cost multi-sensor device that is able to detect the quality conditions of indoor environments for IEQ purposes. The device, hereafter referred as PROMET&O (PROactive Monitoring for indoor EnvironmenTal quality & cOmfort) embeds a set of low-cost sensors that measure air temperature and relative humidity, illuminance, sound pressure level, carbon monoxide, carbon dioxide, particulate matter, formaldehyde, and nitrogen dioxide. The basic architecture of the device is described and the design criteria that are related to the measurement requirements are highlighted. Particular attention has been paid towards the traceability assurance of the measurements provided by PROMET&O by means of specifically conceived calibration procedures, which have been tailored to the requirements of each measurement quantity. The calibration is based on the comparison to reference standards following commonly employed or ad-hoc developed technical procedures. The defined calibration procedures can be applied both for the single sensors and for the set of sensors integrated in the multi-sensor case. For the latter, the effects of the percentage of permeable case surface and the sensors allocation are also investigated. A preliminary uncertainty evaluation of the proposed multi-sensor device is reported for the carbon dioxide and the illuminance sensors taking the defined calibration procedures into account

Indoor Visible Light Communication:A Tutorial and Survey

Abstract With the advancement of solid-state devices for lighting, illumination is on the verge of being completely restructured. This revolution comes with numerous advantages and viable opportunities that can transform the world of wireless communications for the better. Solid-state LEDs are rapidly replacing the contemporary incandescent and fluorescent lamps. In addition to their high energy efficiency, LEDs are desirable for their low heat generation, long lifespan, and their capability to switch on and off at an extremely high rate. The ability of switching between different levels of luminous intensity at such a rate has enabled the inception of a new communication technology referred to as visible light communication (VLC). With this technology, the LED lamps are additionally being used for data transmission. This paper provides a tutorial and a survey of VLC in terms of the design, development, and evaluation techniques as well as current challenges and their envisioned solutions. The focus of this paper is mainly directed towards an indoor setup. An overview of VLC, theory of illumination, system receivers, system architecture, and ongoing developments are provided. We further provide some baseline simulation results to give a technical background on the performance of VLC systems. Moreover, we provide the potential of incorporating VLC techniques in the current and upcoming technologies such as fifth-generation (5G), beyond fifth-generation (B5G) wireless communication trends including sixth-generation (6G), and intelligent reflective surfaces (IRSs) among others

Lighting of University lecture halls:a Design Proposal for Palazzo Malvezzi - Campeggi

Many university lecture halls in Bologna are based inside historic buildings and noble palaces, not designed for students as they are built for a different purpose. The daylight contribution in the rooms is usually not sufficient to satisfy the requirements for school premises; moreover, artificial lighting mainly consists in lamps with high consumption and low performances. Under these conditions the student's visual comfort is not optimal. The following work is based on the open site analysis about the state of art of some university classrooms and their led re-design. The case studies are the lecture halls of Palazzo Malvezzi-Campeggi in Bologna, including the two noble halls on the main floor and the Aula Magna. It has been possible to interact with the acoustic component, not treated here, developing an integrated project able to meet the needs of both parties. The classrooms were qualified through simulations with lighting design software, in accordance with EN 12464, analyzing the daylight factor and the visual comfort parameters

Autonomous Sensing Nodes for IoT Applications

The present doctoral thesis fits into the energy harvesting framework, presenting the development of low-power nodes compliant with the energy autonomy requirement, and sharing common technologies and architectures, but based on different energy sources and sensing mechanisms. The adopted approach is aimed at evaluating multiple aspects of the system in its entirety (i.e., the energy harvesting mechanism, the choice of the harvester, the study of the sensing process, the selection of the electronic devices for processing, acquisition and measurement, the electronic design, the microcontroller unit (MCU) programming techniques), accounting for very challenging constraints as the low amounts of harvested power (i.e., [μW, mW] range), the careful management of the available energy, the coexistence of sensing and radio transmitting features with ultra-low power requirements. Commercial sensors are mainly used to meet the cost-effectiveness and the large-scale reproducibility requirements, however also customized sensors for a specific application (soil moisture measurement), together with appropriate characterization and reading circuits, are also presented. Two different strategies have been pursued which led to the development of two types of sensor nodes, which are referred to as 'sensor tags' and 'self-sufficient sensor nodes'. The first term refers to completely passive sensor nodes without an on-board battery as storage element and which operate only in the presence of the energy source, provisioning energy from it. In this thesis, an RFID (Radio Frequency Identification) sensor tag for soil moisture monitoring powered by the impinging electromagnetic field is presented. The second term identifies sensor nodes equipped with a battery rechargeable through energy scavenging and working as a secondary reserve in case of absence of the primary energy source. In this thesis, quasi-real-time multi-purpose monitoring LoRaWAN nodes harvesting energy from thermoelectricity, diffused solar light, indoor white light, and artificial colored light are presented

A Human-Centered Approach for the Design of Perimeter Office Spaces Based on Visual Environment Criteria

With perimeter office spaces with large glazing facades being an indisputable trend in modern architecture, human comfort has been in the scope of Building science; the necessity to improve occupants’ satisfaction, along with maintaining sustainability has become apparent, as productivity and even the well-being of occupants are connected with maintaining a pleasant environment in the interior. While thermal comfort has been extensively studied, the satisfaction with the visual environment has still aspects that are either inadequately explained, or even entirely absent from literature. This Thesis investigated most aspects of the visual environment, including visual comfort, lighting energy performance through the utilization of daylight and connection to the outdoors, using experimental studies, simulation studies and human subjects’ based experiments

Biophilic and photobiological developments of adaptive high-performance building envelopes for Northern Canada

Les configurations des enveloppes et des fenêtres des bâtiments nordiques doivent répondre aux exigences du bien-être photobiologique et psychologique des occupants par des relations positives efficaces avec la nature subarctique. Les enveloppes de bâtiments existant dans les climats (sub)arctiques du nord du Canada n'ont pas encore permis d'établir des connexions efficaces entre l'intérieur et l'extérieur afin d'aborder les relations positives entre les humains et la nature et le bien-être photobiologique et psychologique. Des connexions intérieures-extérieures efficaces indiquent une connectivité optimale de l'intérieur avec la nature subarctique extérieure répondant au bien-être des occupants et aux besoins énergétiques. Les relations positives des occupants avec la nature subarctique correspondent à des avantages maximums et des risques minimums des climats nordiques extrêmes pour le bien-être photobiologique-psychologique. L'objectif général de cette thèse est de favoriser les relations positives des occupants avec la nature subarctique au moyen de connexions efficaces entre l'intérieur et l'extérieur qui pourraient répondre aux facteurs de bien-être biophiliques et photobiologiques liés à la lumière du jour et aux photopériodes. Dans ce but, un modèle fondamental d'enveloppe de bâtiment adaptative à haute performance est développé comme une solution architecturale qui pourrait optimiser les connexions intérieur-extérieur et les principaux indicateurs biophiliques et photobiologiques. La thèse visait spécifiquement à articuler une approche photobiologique du design biophilique dans les climats nordiques extrêmes qui permet d'établir un cadre conceptuel et de design pour développer des enveloppes de bâtiments. La thèse visait également à identifier les lacunes des enveloppes de bâtiment existantes dans le Grand Nord du Canada ainsi que des systèmes d'enveloppes adaptatives existants en termes d'indicateurs biophysiques-photobiologiques. Les principaux éléments architecturaux des enveloppes adaptatives, notamment la configuration des fenêtres et les caractéristiques de surface des systèmes d'ombrage, en particulier la couleur et la réflectance, sont étudiés pour répondre aux besoins biophiles-photobiologiques des occupants du Nord. Les méthodologies de la thèse comprennent une revue de la littérature pour discuter des directives récentes de design biophilique, de l'éclairage photobiologique et des études de connectivité avec la nature par rapport aux climats subarctiques, en particulier la lumière du jour et les photopériodes. Des méthodes numériques et expérimentales ont été intégrées pour évaluer les performances biophiliques, d'éclairage photobiologique, thermiques et énergétiques des systèmes d'enveloppe pour une étude de cas d'un bureau open-plan dans le nord du Canada. Des méthodes expérimentales avec des modèles à l'échelle physique, des images à haute gamme dynamique et des techniques de post-traitement ont été utilisées pour capturer, calculer et visualiser les paramètres d'éclairage photobiologique. L'impact des caractéristiques des panneaux d'ombrage (SP) sur les performances d'éclairage photobiologique a été étudié par l'expérimentation d'environ 40 prototypes à l'échelle 1:50 et 23 prototypes à l'échelle 1:10 sous un ciel dégagé/couvert avec un éclairage naturel réel/artificiel. Des modèles numériques ont été développés pour évaluer les caractéristiques biophiques et thermiques/énergétiques des systèmes d'enveloppe. Les résultats de la thèse comprennent un cadre théorico-conceptuel du design photobiologique - biophilique qui identifie les relations positives des occupants avec la nature subarctique à travers les enveloppes. Des scénarios d'adaptation de l'éclairage photobiologique intégrés aux exigences thermiques ont été élaborés, qui permettent de répondre aux besoins photobiologiques horaires/saisonniers des occupants du Nord dans des bâtiments différents. Les lacunes des enveloppes à une peau typique du Nord du Canada et des enveloppes à plusieurs peaux avec des profondeurs d'espaces intermédiaires/cavités et des tailles de fenêtre différentes ont été spécifiquement évaluées en termes des indicateurs biophiliques, photobiologiques et thermiques. Un modèle fondamental d'enveloppes adaptatives à haute performance est proposé pour les bâtiments du Nord, qui comprend une taille de fenêtre optimale, un système d'ombrage dynamique coloré et isolé, et un système de buffer thermique constitué d'une peau extérieure en verre. Les performances d'éclairage photobiologique des configurations des SP, incluant la couleur, la réflectance, l'orientation, l'inclinaison, la densité, la taille, l'ouverture et la position à la fenêtre, ont été caractérisées. Les résultats des élévations expérimentales/numériques montrent que l'enveloppe adaptative proposée pourrait offrir des connexions intérieures-extérieures efficaces qui répondent aux besoins photobiologiques-psychologiques et aux exigences énergétiques des occupants du Nord. Les résultats de la thèse pourraient informer les architectes et les responsables politiques sur les possibilités que les enveloppes adaptatives et les cadres photobiologiques-biophiles offrent pour améliorer le bienêtre du public et l'efficacité énergétique dans les climats nordiques. Les principaux enjeux des futurs développements des bâtiments biophiliques adaptatifs dans les climats nordiques ont également été soulignés, notamment en matière d'analyses du cycle de vie et d'études socioculturelles.Sub-Arctic building envelope configurations must address occupants' photobiological-psychological wellbeing through positive relationships with the outdoor sub-Arctic nature. Existing building envelopes in Northern Canada's (sub-)Arctic climates have not, yet, enabled efficient indoor-outdoor connections to address positive human-nature relationships and photobiological-psychological wellbeing. Efficient indoor-outdoor connections indicate optimum connectivity of indoors with Northern climates in terms of occupants' wellbeing and energy factors. Positive occupants' relationships with the sub-Arctic nature refer to maximum benefits and minimum risks of the extreme cold weather and strong photoperiod of Northern climates for photo-biological and psychological wellbeing. The general objective of this dissertation is to foster positive occupants' relationships with sub-Arctic nature by enabling efficient indoor-outdoor connections which could respond to biophilic and photobiological wellbeing factors related to daylighting and photoperiods. To this end, a fundamental model of adaptive high-performance building envelopes is developed as an architectural solution which could optimize indoor-outdoor connections and main biophilic and photobiological indicators. The dissertation specifically aimed at articulating a photobiological approach to biophilic design in extreme Northern climates which enables establishing a conceptual and design framework to develop building envelopes. The thesis also focused on identifying the shortcomings of existing Canadian Northern building envelopes as well as existing adaptive envelope systems in terms of biophilicphotobiological indicators. Main architectural elements of adaptive envelopes including window configuration and surface characteristics of shading systems, in particular color and reflectance, are explored to respond to Northern occupants' biophilic-photobiological needs. The thesis methodologies include a scoping literature review to critically discuss recent biophilic design guidelines, photobiological lighting, and nature connectedness/relatedness studies in relation to sub-Arctic climates, especially daylighting and photoperiods. Numerical and experimental methods were integrated to evaluate biophilic, photobiological lighting, thermal and energy performance of envelope systems for a case study of an open-plan office in Northern Canada. Experimental methods with physical scale models, high dynamic range imagery and post-processing techniques were employed to capture, compute, and visualize photobiological lighting parameters. Impacts of shading panels' (SPs) characteristics on photobiological lighting performance were explored by experimenting approximately 40 1:50-scale prototypes and 23 1:10-scale prototypes under clear/overcast skies with actual/artificial daylighting. Numerical models were developed to evaluate biophilic and thermal/energy performance of envelope systems. Dissertation outcomes include a theoretical-conceptual framework of photobiological-biophilic design which characterizes positive occupants' relationships with the sub-Arctic nature through envelopes. Photobiological lighting adaptation scenarios integrated with thermal requirements were developed which could address hourly/seasonal photobiological needs of Northern occupants in different buildings. Deficiencies of typical single-skin envelopes in Northern Canada and multi-skin envelopes with different depths of intermediate spaces/cavities and window sizes were specifically evaluated in terms of biophilic, photobiological lighting and thermal indicators. A fundamental model of adaptive high-performance envelopes is proposed for Northern buildings which includes an optimum window size, a dynamic-colored-insulated shading system, and a thermal buffer system made of a glazing exterior skin. Photobiological lighting performance of SPs' configurations, including color, reflectance, orientation, inclination, density, size, openness, and position at the window, were characterized. Results of experimental-numerical elevations reveal that the proposed adaptive envelope could offer efficient indoor-outdoor connections which respond to Northern occupants' photobiological-psychological needs and energy requirements. Dissertation outcomes could enlighten architects and policymakers about potentials of adaptive envelopes and integrative photobiological-biophilic frameworks to improve public wellbeing and energy efficiency in Northern climates. Major issues for future developments of adaptive biophilic buildings in Northern climates were also outlined including life cycle assessments and sociocultural studies

Internet of light: Technologies and applications

Intelligent lighting has attracted lots of research interests to investigate all the possible schemes to support this need as human has spent more and more time indoor. Semiconductor-based illumination network is an ideal bearer to carry on this mission. In this paper, we propose the concept of Internet of Light (IoL) and define its key functionalities by introducing the information and communication technologies to the illumination networks. Our latest research progress on high-speed transmission, resource optimization, and light stroboscopic irradiation experiment based on IoL platform show that IoL can not only provide value-added services such as positioning and information transmission but also act like a sensor network as part of Internet of Things infrastructure. It confirms that with sensors for different purposes integrated into the lamp, IoL helps people be aware of the environmental changes and make the adjustment accordingly, can provide cost-effective information service for Internet of Things applications, and supports the non-intrusive optical therapy in the future