Alessandro Cannavale | Politecnico di Bari (original) (raw)

Papers by Alessandro Cannavale

Applied Sciences

Among the adaptive solutions, phase change material (PCM) technology is one of the most developed... more Among the adaptive solutions, phase change material (PCM) technology is one of the most developed, thanks to its capability to mitigate the effects of air temperature fluctuations using thermal energy storage (TES). PCMs belong to the category of passive systems that operate on heat modulation, thanks to latent heat storage (LHS) that can lead to a reduction of heating ventilation air conditioning (HVAC) consumption in traditional buildings and to an improvement of indoor thermal comfort in buildings devoid of HVAC systems. The aim of this work is to numerically analyze and compare the benefits of the implementation of PCMs on the building envelope in both active and passive strategies. To generalize the results, two different EnergyPlus calibrated reference models—the small office and the midrise apartment—were considered, and 25 different European cities in different climatic zones were selected. For these analyses, a PCM plasterboard with a 23 °C melting point was considered in f...

Applied Sciences, 2021

Electrochromic (EC) devices essentially modulate the energy flux of solar energy through windows.... more Electrochromic (EC) devices essentially modulate the energy flux of solar energy through windows. This can be obtained by either controlling absorbance or reflectance. An EC glass can be considered, given the strict electrochemical analogy, as an electric battery embodying thin films of specific materials, whose loading degree is related to the degree of optical transparency. A pivotal component in EC devices is indeed the electrolyte, which is able to conduct ions but also acts as an insulator for electrons. Electrolytes typically used in EC systems are in the liquid, gel or solid state of aggregation. Liquid electrolytes may be subject to leakage or evaporation if they contain solvents. The ions shuttling through the electrolyte, upon the application of the external bias, are predominantly hydrogen and lithium or, more rarely, sodium. EC materials used in devices are mainly transition metal oxides and organic materials.

Buildings

Here, we overview the Buildings journal Special Issue dedicated to the following topic: “Novel Te... more Here, we overview the Buildings journal Special Issue dedicated to the following topic: “Novel Technologies to Enhance Energy Performance and Indoor Environmental Quality of Buildings” (https://www [...]

E3S Web of Conferences

Thermal performances of window frames and glazing represent a field of growing research efforts -... more Thermal performances of window frames and glazing represent a field of growing research efforts - worldwide - aiming to reduce energy consumption and achieve indoor comfort. A combination of newly designed super-insulated window frames and innovative glazing technologies may enhance the performance of windows. Aerogel-based “thermal breaks” for window frames, coupled with high-performing glazing, may lead to significant energy saving. In this work, yearly energy use for heating and cooling were assessed in several locations, for building models equipped with innovative technologies, for glazing and frames. The results of numerical simulations confirmed the opportunities offered by new technologies.

Clean Technologies

Chromogenic materials and devices include a wide range of technologies that are capable of changi... more Chromogenic materials and devices include a wide range of technologies that are capable of changing their spectral properties according to specific external stimuli. Several studies have shown that chromogenics can be conveniently used in building façades in order to reduce energy consumption, with other significant effects. First of all, chromogenics influence the annual energy balance of a building, achieving significant reductions in consumption for HVAC and artificial lighting. In addition, these technologies potentially improve the indoor level of visual comfort, reducing the risks of glare and excessive lighting. This brief review points to a systematic discussion—although not exhaustive and mainly limited to recent results and investigations—of the main studies that deal with building-integrated chromogenics that have appeared, so far, in the scientific literature.

Energies

This paper holds a critical review of current research activities dealing with smart architectura... more This paper holds a critical review of current research activities dealing with smart architectural glazing worldwide. Hereafter, the main trends are analyzed and critically reported, with open issues, challenges, and opportunities, providing an accurate description of technological evolution of devices in time. This manuscript deals with some well-known, highly performing technologies, such as semitransparent photovoltaics and novel photoelectrochromic devices, the readiest, probably, to reach the final stage of development, to disclose the manifold advantages of multifunctional, smart glazing. The complex, overall effects of their building integration are also reported, especially regarding energy balance and indoor visual comfort in buildings.

Applied Sciences

The use of titanium dioxide (TiO2) within two specific classes of devices, namely electrochromic ... more The use of titanium dioxide (TiO2) within two specific classes of devices, namely electrochromic and photoelectrochromic, is described hereafter, with respect to its inherent properties and chromogenic features within architectures that have appeared so far, in this field. The new research trends, involving the applications of TiO2 in chromogenic materials are reported, with particular attention paid to the techniques used for film deposition as well as the synthesis of nanoparticles. Furthermore, the main studies concerning its chemical-physical properties and approaches to its chemical syntheses and fabrication are reviewed, with special regard to “green” routes. In addition, the main aspects relating to toxicological profiles are exposed, with reference to nanoparticles and thin films.

Energies, Apr 14, 2020

Buildings

Research activities in the field of innovative fixtures are continuously aiming at increasing the... more Research activities in the field of innovative fixtures are continuously aiming at increasing their thermal and optical performances to offer optimal exploitation of daylight and solar gains, providing effective climate screen, according to increasing standards for indoor comfort and energy saving. Within this work, we designed an innovative aerogel-based “thermal break” for window frames, so as to consistently reduce the frame conductance. Then, we compared the performance of this new frame both with currently used and obsolete frames, present in most of the existing building stock. Energy savings for heating and cooling were assessed for different locations and confirmed the potential role played by super-insulating materials in fixtures for extremely rigid climates.

Buildings, 2020

Research activities in the field of innovative fixtures are continuously aiming at increasing the... more Research activities in the field of innovative fixtures are continuously aiming at increasing their thermal and optical performances to offer optimal exploitation of daylight and solar gains, providing effective climate screen, according to increasing standards for indoor comfort and energy saving. Within this work, we designed an innovative aerogel-based "thermal break" for window frames, so as to consistently reduce the frame conductance. Then, we compared the performance of this new frame both with currently used and obsolete frames, present in most of the existing building stock. Energy savings for heating and cooling were assessed for different locations and confirmed the potential role played by super-insulating materials in fixtures for extremely rigid climates.

IOP Conference Series: Materials Science and Engineering

Innovative nanotechnology-based devices can offer multiple advantages in terms of renewable energ... more Innovative nanotechnology-based devices can offer multiple advantages in terms of renewable energy harvesting as well as energy saving in buildings. Among the technologies that can be used in transparent and semi-transparent building envelopes, neutral-colored perovskite-based heterojunction photovoltaic (PV) cells and solid-state electrochromic (EC) devices may play a pivotal role. These classes of devices have proven to offer significant benefits in terms of energy saving and enhancement of indoor visual comfort. In this work, the two types of technologies will be compared by considering two similar buildings equipped with glazing embodying such devices, with reference to specific climate conditions.

TECNICA ITALIANA-Italian Journal of Engineering Science

Phase Change Materials (PCM), being able to supply dynamic thermal capacity due to their relative... more Phase Change Materials (PCM), being able to supply dynamic thermal capacity due to their relatively high enthalpy of fusion, have largely shown a great potential for energy saving in buildings. Bio-compatible nanostructured shape-stabilized PCMs, with a specifically designed core-shell structure, already reported in a previous work, were studied here, with reference to lightweight constructions, carrying out dynamic simulations, adopting a multiparametric approach. Suitable figures of merit for thermal comfort indoor were adopted, with this aim.

TECNICA ITALIANA-Italian Journal of Engineering Science

Office and industrial buildings are characterized by very regular occupation patterns and even bu... more Office and industrial buildings are characterized by very regular occupation patterns and even building systems are normally scheduled (unless they are controlled by energy management systems). So, under these conditions, either at a detail scale (single office) or at a global scale, variations in energy usage (for both HVAC and lighting) may have a strong relation with outdoor conditions. Modelling and forecasting energy use in such large buildings may be essential to prevent energy shortage and blackouts , as well as to take action in terms of adaptive measures to ensure occupants' comfort conditions. As the number of smart devices to monitor outdoor weather and air quality conditions is constantly increasing, it might be useful to investigate whether parameters derived from such monitoring stations might be used as proxy variables to predict indoor conditions and, above all, energy consumptions. In order to create a dataset to test forecasting models, different office and industrial buildings have been simulated under dynamic conditions by means of the Energy Plus tool as a function of different climatic data. Then, machine learning algorithms (mostly based on artificial neural networks) were used to predict both energy consumptions and indoor environment conditions as a function outdoor parameters. A study of the short term and long term reliability of prediction models is finally presented.

Energy and Buildings

Abstract The paper presents the results of an experimental activity aimed at producing and charac... more Abstract The paper presents the results of an experimental activity aimed at producing and characterizing a nano-encapsulated PEG600 (PCMs) into a silica shell. The nano-encapsulation was meant to be useful to improve the material's suitability to integration in building components. The (300 ± 15) nm nanoparticles that were produced underwent a full characterization of their thermal performances. An enthalpy of fusion as high as 66.24 kJ/kg, in a tight melting temperature range (20–21 °C) was obtained, making the material suitable for thermal energy storage in buildings. In order to demonstrate the benefits of such as this technology on the reduction of heating and cooling demand of buildings, a concentration of 50% in weight of nanoparticles was, then, embedded into a gypsum plasterboard and used for all indoor plastered surfaces of a reference residential buildings. A saving of respectively up to 4.3% and up to 1.1% of heating and cooling energy demand was predicted in comparison to the ones of a building without PCM. Finally, the material underwent a full toxicological characterization exposing human alveolar basal epithelial cells to nanoparticles. The results showed that there were no toxic effects on cell morphology.

Applied Energy

Abstract The next generation of adaptive facades includes dynamic electrochromic (EC) windows: th... more Abstract The next generation of adaptive facades includes dynamic electrochromic (EC) windows: they can dynamically modulate the daylight and solar energy entering buildings by application of an external voltage. Windows play a pivotal role in the definition of the energy balance as well as environmental impacts of buildings. Emerging technologies are focused on the optimization of these building components. We carried out an interdisciplinary study dealing with building integration of an innovative chromogenic technology, consisting in a recently designed single substrate solid–state electrochromic device, developed by some of the authors, with excellent figures and a compact device architecture. The practical implications on the building energy balance were analyzed by means of suitable simulations, carried out in Energy Plus. A reference office building was equipped with different glass technologies on the facade (clear glass, solar control, electrochromic glasses) and located in different cities (Rome, London and Aswan) to also include climatic effects in the analysis. The EC technology here presented outperforms all the others, with overall yearly energy savings as high as 40 kW h/m2 yr (referred to window surface) in the hottest climates, assuming the clear glazings as benchmark. Daylighting performances were significantly improved using innovative solid-state EC devices, both in terms of Useful Daylight Illuminance (UDI) and Discomfort Glare Index (DGI). In the best case, 82.7% of hours achieved optimal illuminance conditions on an annual basis.

Energy Procedia

Abstract Adaptive facades, like electrochromic (EC) smart windows, represent the next generation ... more Abstract Adaptive facades, like electrochromic (EC) smart windows, represent the next generation of glazing with dynamic modulation of transparency, to suitably modulate the daylight and solar energy entering buildings. A study is reported, dealing with the manifold effects of building integration of an innovative solid-state EC device, assessing effects on the building energy balance and daylighting performance, in terms of Useful Daylight Illuminance (UDI) and Discomfort Glare Index (DGI). All the analyses were carried out using the experimental results, reporting the main figures of merit of EC devices as an input for building simulations, in the EnergyPlus software.

Applied Sciences

Due to their extraordinary quality factor and extreme sensitivity to surface perturbations, Bloch... more Due to their extraordinary quality factor and extreme sensitivity to surface perturbations, Bloch surface waves (BSW) have been widely investigated for sensing applications so far. Over the last few years, on-chip control of optical signals through BSW has experienced a rapidly-expanding interest in the scientific community, attesting to BSW's position at the forefront towards on-chip optical operations. The backbone of on-chip optical devices requires the choice of integrated optical sources with peculiar optic/optoelectronic properties, the efficient in-plane propagation of the optical signal and the possibility to dynamic manipulate the signal through optical or electrical driving. In this paper, we discuss our approach in addressing these requirements. Regarding the optical source integration, we demonstrate the possibility to couple the MoS 2 mono-and bi-layers emission-when integrated on top of a 1D photonic crystal-to a BSW. Afterward, we review our results on BSW-based polariton systems (BSWP). We show that the BSWPs combine long-range propagation with energy tuning of their dispersion through polariton-polariton interactions, paving the way for logic operations.

Energy Procedia

Abstract Building integration of photovoltaics (BIPVs) has been recognized worldwide as a pivotal... more Abstract Building integration of photovoltaics (BIPVs) has been recognized worldwide as a pivotal technology enabling the exploitation of innovative renewable energy sources in buildings, acting as electric power generators within the new framework of smart cities. Photovoltaic (PV) modules can be designed as relevant components of building envelopes, energy-producing units, fulfilling the multiple requirements of construction elements. Their integration in architectural glazings is still impeded by the inherent optical features of commercial solar cells, but also aesthetic, economic and social constraints, still acting as relevant barriers. In this roadmap, novel PV technologies could be effective drivers of a real change of paradigm. We have recently demonstrated that a coherent and exhaustive study of BIPV for semitransparent cells requires a “holistic approach”, taking into account the complex fallouts of semitransparent modules on the energy balance, but also the full assessment of visual comfort benefits deriving from their integration in glazings. We have demonstrated that BIPV could offer manifold advantages: visual comfort effects comparable to commercially available solar control glasses and fair energy yield. Moreover, we found that in several cases the annual energy production overcomes the amount of electric energy used for artificial lighting.

Applied Energy, 2017

h i g h l i g h t s Innovative transparent perovskite-based BIPVs cells were studied. Yearly ener... more h i g h l i g h t s Innovative transparent perovskite-based BIPVs cells were studied. Yearly energy yield and visual comfort benefits were calculated. The effect of different climate conditions was also investigated. Energy yield varied between 10 and 30 kWh/m 2 per year. PV cells behaved like solar control films.

Applied Sciences

Applied Sciences, 2021

Buildings

E3S Web of Conferences

Clean Technologies

Energies

Applied Sciences

Energies, Apr 14, 2020

Buildings

Buildings, 2020

Research activities in the field of innovative fixtures are continuously aiming at increasing the... more Research activities in the field of innovative fixtures are continuously aiming at increasing their thermal and optical performances to offer optimal exploitation of daylight and solar gains, providing effective climate screen, according to increasing standards for indoor comfort and energy saving. Within this work, we designed an innovative aerogel-based "thermal break" for window frames, so as to consistently reduce the frame conductance. Then, we compared the performance of this new frame both with currently used and obsolete frames, present in most of the existing building stock. Energy savings for heating and cooling were assessed for different locations and confirmed the potential role played by super-insulating materials in fixtures for extremely rigid climates.

IOP Conference Series: Materials Science and Engineering

TECNICA ITALIANA-Italian Journal of Engineering Science

Energy and Buildings

Applied Energy

Energy Procedia

Applied Sciences

Energy Procedia

Applied Energy, 2017