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Green roofs represent a growing technology that is spreading increasingly and rapidly throughout the building sector. The latest national and international regulations are promoting their application for refurbishments and new buildings to increase the energy efficiency of the building stock. In recent years, vegetative coverings have been studied to demonstrate their multiple benefits, such as the reduction of the urban heat island phenomenon and the increase in the albedo of cities. On the contrary, this study aims to verify the actual benefit of applying a green roof on a sloped cover compared with installing a highly insulated tiled roof. The EnergyPlus tool has been used to perform dynamic analyses, which has allowed to understand the behavior of two different stratigraphies in accordance with weather conditions, rain, and irrigation profiles. Results have shown that the installation of a green roof cannot always be considered the best solution for reducing building energy consumption, especially if compared with a classic highly insulated clay tile roof. In terms of summer air conditioning, the maximum saving is 0.72 kWh/m2. The presence of water in the soil has also been proven a crucial factor.

The evaluation of Indoor Environmental Quality (IEQ) can be applied to special environments such as hospitals where it can have a great impact on both patients and workers. In this paper the authors present some results obtained in a large survey campaign in hospital settings, and in particular the results of IEQ measures in the sterilization unit are shown.

Here we will review our current activities on the realization of photonic active structures based on biomaterials. Nanofibers of DNA incorporating light-emitting chromophores are reported with enhanced optical emission and lasing properties tailorable by the fiber size and architecture. The research leading to these results has received funding the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (grant agreement No. 682157, “xPRINT”) and from the Italian Minister of University and Research through the PRIN 201795SBA3 project.

From the introduction of the “Moon Village” concept by the ESA Director General Jan Worner, the interest towards a permanent settlement on the Moon increased. International space agency and private companies started to investigate and design new solutions for permanent habitats on lunar soil. Many aspects in the design of space residences must be considered, with the awareness that human health and well-being must be at the centre of every design choice. The first aim of this paper is to outline the key aspects of two lunar habitats concepts, One Moon, developed by ESA, and MaMBA. Furthermore, the key issues related to an engineering design of the modules are discussed, with a particular attention to the thermo-energetic aspects. The issues of thermal comfort and energetic evaluation in living environments is becoming increasingly studied, with numerous reliable and tested tools for assessing ordinary places. The same can hardly be said for hostile places, where the safety and well-being of people are more difficult to provide. Therefore, a review of the main data needed for an energetic analysis of such a hostile place as the lunar planet is provided and analysed, with the intention to maximizes in-situ resource utilization.

The thermal environment in educational buildings is crucial to improve students’ health and productivity, as they spend a considerable amount of time in classrooms. Due to the complexity of educational buildings, research performed has been heterogeneous and standards for thermal comfort are based on office studies with adults. Moreover, they rely on single dose-response models that do not account for interactions with other environmental factors, or students’ individual preferences and needs. A literature study was performed on thermal comfort in educational buildings comprising of 143 field studies, to identify all possible confounding parameters involved in thermal perception. Educational stage, climate zone, model adopted to investigate comfort, and operation mode were then selected as confounding parameters and discussed to delineate the priorities for future research. Results showed that children often present with different thermal sensations than adults, which should be considered in the design of energy-efficient and comfortable educational environments. Furthermore, the use of different models to analyse comfort can influence field studies’ outcomes and should be carefully investigated. It is concluded that future studies should focus on a more rational evaluation of thermal comfort, also considering the effect that local discomfort can have on the perception of an environment. Moreover, it is important to carefully assess possible relationships between HVAC systems, building envelope, and thermal comfort, including their effect on energy consumption. Since several studies showed that the perception of the environment does not concern thermal comfort only, but it involves the aspects of indoor air, acoustic, and visual quality, their effect on the health and performance of the students should be assessed. This paper provides a way forward for researchers, which should aim to have an integrated approach through considering the positive effects of indoor exposure while considering possible individual differences.

Heat stress is a typical health problem in glass industries, due to the high temperatures that can be reached in these spaces, especially close to the furnaces. For this reason, the evaluation of the conditions in these environments is particularly important. In this paper, the aim is to assess the workers' exposure in an Italian glass industry to the severe environment present in the furnace area, through the use of the WBGT index. Furthermore, the maximum time that they can spend in the industry warm area was also evaluated for different types of clothing and of metabolic rates, in order to reduce the health risk that may occur.

To estimate and predict the energy savings achievable with Building Automation and Control Systems, dynamic simulations are of fundamental importance. Such simulations can be performed with different types of software, among which, those based on simplified physical models are currently studied in the scientific literature. In fact, they can represent a fair compromise between the computational demand and the result accuracy. This paper shows how the CARNOT Toolbox for MATLAB/Simulink® can be effectively used for evaluating the impact of the automation system (used to manage the heating system) on the energy performance of a study case building. The building is located in the historic center of Pisa, Italy, and it is characterized by high wall thickness, which results in high thermal inertia. The building heating system has two type of heat generators: an air to water heat pump and a condensing boiler. The rooms of the building, currently used as offices, are heated by fan coil units. The control system, that manages the heating system, consists of a central multi-controller and a logical interface. They communicate, using the Modbus protocol, with all the components of the heating system that are connected by a bus cable. In the paper, the energy consumptions and CO 2 emissions of the building were evaluated for different scenarios, characterized by the implementation of different control functions of the heating system, selected according to the EN 15232 technical standard specifications.

Lasers based on biological materials are attracting an increasing interest in view of their use in integrated and transient photonics. Deoxyribonucleic acid (DNA) as optical biopolymer in combination with highly emissive dyes has been reported to have excellent potential in this respect. However, achieving miniaturized lasing systems based on solid‐state DNA shaped in different geometries to confine and enhance emission is still a challenge, and the physicochemical mechanisms originating fluorescence enhancement are not fully understood. Herein, a class of wavelength‐tunable lasers based on DNA nanofibers is demonstrated, for which optical properties are highly controlled through the system morphology. A synergistic effect is highlighted at the basis of lasing action. Through a quantum chemical investigation, it is shown that the interaction of DNA with the encapsulated dye leads to hindered twisting and suppressed channels for the nonradiative decay. This is combined with effective waveguiding, optical gain, and tailored mode confinement to promote morphologically controlled lasing in DNA‐based nanofibers. The results establish design rules for the development of bright and tunable nanolasers and optical networks based on DNA nanostructures., Miniaturized, wavelength‐tunable lasers based on deoxyribonucleic acid (DNA) nanofibers might combine enhanced stability of embedded dyes and tailored emission through morphology control. Here, these systems are studied by a quantum chemical investigation of the DNA–dye interactions, and elucidated in their waveguiding and mode confinement properties that lead to morphologically tailored lasing from the doped DNA structures.

Energy demand represents a global challenge that calls for innovative energy solutions. Road lighting contributes in a small part to the overall worldwide electricity consumption, however the possibilities for energy saving are numerous. The road lighting should provide the required lighting quality, in the most energy efficient way as possible. In this paper the Authors analyze, compare and discuss the numerical indicators currently used to evaluate the lighting and the energy performance of new-designed and existing road lighting systems. To support the discussion, the use of the case study of road lighting of the historic town center of Pisa is proposed. For the case study the Authors have chosen a significant sample of 20 roads representative of 80 similar roads located in the historic town center. For the sample, geometric surveys, luminance and illuminance measurements, calculation of the national and international energy performance indicators have been carry out. The considerations made by the Authors, obtained with an investigation procedure of general validity, are useful to point out strengths and weaknesses of each indicator and to provide suggestions on the use of the appropriate indicators during the design stage of road lighting systems.

Within the diagnostic process, in the activities in which digital radiology systems are utilised, image display devices play a very important role. Such devices have to guarantee high performances in order to maintain the diagnostic quality of the displayed images and present them so that they can be observed optimally. In order to ensure the appropriate performance to the users, not only the image display device but also the whole workstation should be designed properly. Particular attention should be paid to the lighting conditions, to avoid compromising the radiologist's ability to observe the displayed images. The aim of this study is to assess the lighting of some workstations used for diagnostic radiology reporting, in order to obtain information about the visual interaction between worker and device and prevent health risks. A detailed analysis of the lighting of adjustable and nonadjustable workstations used for diagnostic radiology reporting was carried out in different rooms of the Radiology Department at the “Felice Lotti” Hospital in Pontedera (Pisa, Italy). The analysis was carried out thanks to in situ measurements (objective analysis) and the submission of an evaluation questionnaire to a sample composed by 16 radiologists (subjective analysis). From the obtained results it has been possible to point out that, in nonadjustable workstations the absence of a dedicated lighting system very often reveals the inadequacy of the general lighting in guaranteeing correct lighting conditions for the radiologists during the reading of the diagnostic monitors. As measure to reduce the visual fatigue of the radiologists, the use of a supplementary adjustable innovative LED backlight system was proposed. The use of the LED backlight system allows complying the requirements of the Technical Standards and mitigate the difference of luminance in the field of view of the radiologist. Due to that the use of the LED backlight system has been positively perceived by the examined sample, a significant part of whom has ascribed to this use a reduction in the visual fatigue.

The hygrothermal behaviour of the opaque building envelope (facades and roofs) is a topic worthy of investigation for the scientific community, especially in consideration of changes in construction techniques and lifestyle habits. For the presence of waterproofing layers, placed in the outer part of a structure, hygrothermal behaviour of flat roofs is of particular interest. In this paper, an original analytical model for evaluation of the hygrothermal behaviour of ventilated flat roofs is proposed. In particular, the authors provide a method for assessing the ventilation air flow rates necessary to avoid interstitial condensation in flat roofs. Dependency of the necessary ventilation air flow rates on geometrical, thermophysical, and climate parameters is investigated and discussed. After a simplified analytical treatment applicable to any type of ventilated flat roof, some examples are shown, referred to study cases of flat roofs that are very widespread in Italy. The results obtained by the authors and discussed in the paper can be useful for architects and building engineers during the early design stage of buildings.

Lighting cultural heritage is a complex task that requires considering the conservation needs of the exhibits and visitors’ visual comfort. However, these needs are often in contrast. In addition, whenever the exhibitions are displayed inside historical buildings, the task further complicates, as lighting designers must face and respect the architectural character of the host building. They have two mean of work: static and dynamic analysis. The former uses the Daylight Factor (DF) while the latter requires a prolonged and expensive measurement campaign. Both analyses present advantages and shortcomings: the DF approach is easy and fast, but it implies many oversimplifications whereas the annual approach provides accurate results but is time and money-consuming. In this paper the authors analyse a case study with both methods. The case study is the Cetacea’s Gallery of the Charterhouse of Calci (PI). The findings of this research demonstrate that the annual approach is preferable, despite its costs, and that the static approach should be used just for first instances analyses. The research pointed out the necessity of a standardized procedure of evaluation that would allow lighting designers to confront possible interventions and find the most adequate to solve the conservation and comfort issues of the case in exam.

The spectral emission of LED displays has a blue component that can potentially impact human health under both the photobiological and the circadian point of view. In this paper the spectral emission of three LED display has been measured and analyzed. For each display, 21 different combinations of screen settings (white, white with black test, black, and blue), brightness levels (100% and 500%) and observation distances (20 cm, 50 cm and 70 cm) have been experimentally evaluated within a test cabin equipped with a spectrophotometer and a broad band photoradiometer. The photobiological safety and circadian effects have been analyzed in order to evaluate the interaction between displays and human health.

Street lighting is an indispensable feature for the night landscape of cities. It is important for road safety, users visual comfort, crime prevention and to augment the perceived personal safety. Realize and maintain an adequate street lighting service is very expensive for municipalities with significant impact on their budgets. For this reason, special attention should be paid to the design of new street lighting systems and to the refurbishment of existing ones, since many of them are inadequate. In light of this it is very important to implement street lighting designs that fulfil lighting requirements avoiding energy waste and light pollution and, at the same time, result economically sustainable for municipalities. In this paper, an original step by step methodology for the lighting, energy and economic analysis of street lighting refurbishment designs has been introduced and explained in detail. The methodology is suitable for use in cities of different sizes. As an applicative example, the methodology has been tested in the town of Pontedera (Italy) and the results are discussed, also providing a sensitivity analysis of the economic feasibility with respect to the variations of electricity prices and investment costs.

HAABitat is the name of the project developed by a team of students from three different Italian Universities: the University of Pisa, the University "D'Annunzio" of Pescara, and the Second University of Naples. The aim of the project is to design, build and test an innovative self-sufficient house, which works with the sun as the only source of energy, employing advanced technologies and sustainable materials. HAABitat is one of the finalist projects of the Solar Decathlon Middle East competition, where students from all over the world challenge, to achieve the best "solar house", which combine efficiency, comfort, engineering, and architectural design to sustainability. Students of Team HAAB, supported by professors of the three Universities, have the chance to complete the knowledges learned in their course of studies with a practical application, relating to professionals and companies, in order to learn how to deal with responsibilities and challenges the world of work introduces. The aim is to reach a thorough education, which involves the whole aspects of the product design and realization, with a "learning by doing" experience.

In this paper, the authors discuss the results of a measurement survey of artificial optical radiation emitted by 8 W LED tubes suitable for the substitution of 18 W fluorescent lamps used for general lighting. For both types of lamps, three different color temperatures were chosen, 3000 K, 4000 K, and 6000 K. These measurements were performed to evaluate the photobiological safety of the sources. The radiance and irradiance values have been measured in a wide range of wavelengths (180–3000 nm). The measurement results obtained for the LED tubes have been compared to those of similar measurements obtained for fluorescent lamps. The analysis has been focused on the range of wavelengths 300–700 nm, the blue light range, which turned out to be defining for the risk groups of the lamps. This classification is a function of the maximum permissible exposure time as indicated in the European Standard EN 62471 on the photobiological safety of lamps and lamp systems.

The lighting system in a sport facility is a crucial element for the success of sports activity. In this work, the development of an innovative procedure, for the in situ measurements of vertical illuminance in fencing halls, is described and discussed. The measurement procedure has been obtained from a detailed analysis of the game phases of a fencing competition, considering the assessment of the visual conditions of both opponents. The procedure allows to obtain measurement results that can be compared with the requirements fixed by the technical standards and can be used for the evaluation of the adequacy of the lighting system with respect to the athletes' main visual tasks.

In this paper the authors describe in detail the exposure limit values concerning artificial optical radiation due to the main incoherent light sources found in offices. In particular, for some examples of significant sources chosen as case studies, we discuss the results of in situ measurements of the exposure values using a broadband photoradiometer. By comparing the measurement results with the exposure limit values specified in the European legislation, the maximum exposure times for workers have been evaluated. From the analysis of the results it can be concluded that the lighting sources typically present in indoor workplaces under usual conditions of use, do not pose a health risks for workers. However, in the case of accidental exposure during work activities or exposure linked to maintenance activities (short exposure distance), values in excess of the limit values have been observed, with decidedly short maximum exposure times.

The energy audit for a building is a procedure designed mainly to obtain adequate knowledge of the energy consumption profile, identify, and quantify opportunities for energy savings by a cost-benefit analysis and report, clearly and comprehensively, about the obtained results. If the audit is referred to a building with a significant historical and artistic value, a compatibility evaluation of the energy saving interventions with the architectural features should also be developed. In this paper, analysing the case study of a historical building used as public offices in Pisa (Italy), the authors describe how it is possible to conduct an energy audit activity (especially dedicated to the lighting system) and they show how, for this type of buildings, it is possible to obtain significant energy savings with a refurbishment of the lighting system. A total number of seven interventions on indoor and outdoor lighting sub-systems were analysed in the paper. They are characterised by absolute compatibility with the historical and artistic value of the building and they show short payback times, variable between 4 and 34 months, allowing a reduction of the electrical energy consumption for the artificial indoor and outdoor lighting variable from 1.1 MWh/year to 39.0 MWh/year. The followed methodology and the evaluation results described in the paper, although based on a case study, can be extended to numerous historical buildings used as public offices, a recurring situation in the centres of Italian historical cities.

The energy audit for a building is a procedure designed mainly to obtain adequate knowledge of the energy consumption profile, identify and quantify opportunities for energy savings by a cost-benefit analysis and report, clearly and comprehensively, about the obtained results. If the audit is referred to a building with a significant historical and artistic value should be also developed a compatibility evaluation of the energy saving interventions with the architectural features. In this paper, discussing the energy audit carried out for the historical building named “Palazzo Medici” in Pisa (Italy), the Authors analyses, from a techno-economic standpoint, different possible interventions on the lighting systems aimed to obtain significant energy saving. The total of six interventions on indoor and outdoor lighting systems, analyzed in the paper, allow a reduction of about 35% of the electrical energy demands for the artificial lighting of indoor and outdoor spaces, with a very short payback times. From the results obtained by the Authors, it is possible to show that, for historical buildings used for public functions, interventions to improve energy efficiency of lighting systems may allow significant reductions in the electrical energy consumption, which, in some cases, may reach or exceed the 20% of the overall electrical energy consumption.

The risk assessment from exposure to artificial optical radiation (AOR) has long been analyzed. Minor attention has been paid to incoherent sources used in offices (e.g. lamps, LED for lighting). The LED is becoming one of the most widespread light sources. Due to spectral characteristics of white LEDs some concerns have been raised regarding their safety for human health. The minimum requirements to protect workers against risks to health and safety that may result from exposure to the AOR are specified in the EU Directive 2006/25. In this paper the Authors discuss the results of a measurement survey of AOR emitted by LEDs suitable for substitution of lamps used in lighting. These results have been compared with the results of similar measurements on fluorescent tubes. The risk analysis was thorough in the range 300÷700nm (Blue Light Hazard) to define the Risk Group of LED in function of the exposure time as indicated in the EN 62471 on photobiological safety of lamps.

This paper proposes the use of a simplified analytical model to evaluate acoustic conditions in restaurant dining rooms required for ensuring the intelligibility of conversations. The model is useful for design applications and is suitable for evaluating the maximum number of speakers present in a restaurant room in order to ensure intelligibility of conversations taking place at each table in the presence of background noise caused by conversations at other tables. The maximum number of speakers is studied in relation to the sound level difference between useful and disturbing sound, sound absorption of the room, and the average speaker–listener distance. The model is applied to the case of a dining hall in a multipurpose centre, which is currently in the planning stage.

In this paper, the authors propose a techno-economic comparative analysis between different lighting solutions, using, respectively, floodlight with metal halide lamps, luminaires with fluorescent lamps and LED floodlights. The comparison is aimed to identify general criteria for assessing the techno-economic sustainability of the use of LED lighting for indoor sports facilities, since this solution is very often proposed to achieve a reduction of the electrical power for lighting. From a technical standpoint, the analysis takes into particular consideration the aspects related to the satisfaction of lighting requirements, safety and energy efficiency. From an economic standpoint the investment, the operating and the maintenance costs are evaluated. To make comparisons on an economic basis, specific indicators are used. From the obtained results it is possible to highlight as the solution that uses the LED floodlights is characterized by highest energy efficiency. This solution requires a smaller number of luminaires and it has limited maintenance costs compared to the other solutions, but it has high investment costs, which involve reasonable payback times only when the sports facility is used intensively and for competitions of high level.

Highly compact Periodic Two-Phase Thermosyphon (PTPT) cooling devices joined with a thermoelectric cooler can allow a wide flexibility in the design of CFC-free refrigerators. In this paper a method has been presented to experimentally evaluate the PTPT evaporator heat transfer coefficient highly changing over time. Copyright , Manchester University Press.

In the last few years, to meet the need of build efficient homes in a short time and with maximum constructive simplification, lightweight prefabricated building systems have proved to be particularly suitable, especially in geographical areas which must deal with emergency situations (i.e., temporary housing). In this paper the winter and summer thermal performance of a building prototype, realised with modular steel framed elements, have been studied, in both winter and summer conditions. Special attention has been paid to the optimisation of the dynamic thermal performance of the multi-layered envelope structures. The dynamic thermal behaviour of the outer wall, analysed and discussed in details in the paper, shows that it is possible to improve the performance of lightweight walls by using an optimised stratigraphy characterised by an opportune sequence of resistive and capacitive layers. The influence of inner structures (partitions, floor and roof) on the building thermal behaviour has also analyzed trough the introduction of room performance indices appropriately defined. The results of the study have been discussed with special reference to the requirements fixed by the Energy Performance Buildings European Directive (EPBDs) and the resulting implementation in Italian Legislation.