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The study and analysis of the processes that determine environmental sustainability of buildings are nowadays topics of great interest for the sustainable, economic and social development of the cities. The international context presents guidelines and protocols for the energy-environmental sustainability, often aimed to assigning a sustainability label to the buildings. In Italy one of the most used rating systems is the ITACA Protocol, recently updated by the Italian Standard UNI/Pdr 2019, which through a series of criteria identifies global indicators of the sustainability of the building examined. This paper presents the potential of the ITACA protocol which could be a method for designing innovative and efficient architectures. In particular, the aspects related to the acoustic comfort are examined and how these criteria change the overall performance of a building. The evaluation of the sustainability performance was applied to a school building. Results show that an optimal acoustic quality improve over to 2 point of the final protocol score.

A proper evaluation of the building energy consumption implies an accurate assessment of the solar gains and consequently an exact estimation of the direct and diffuse solar radiation on tilted and oriented surfaces. The new standard EN ISO 52016-1: 2017 introduces a new hourly methodology for the calculation of energy performance of buildings and is complemented by EN ISO 52010-1:2017, which specifies the procedure for the conversion of climate data for energy calculations. These standards represent a good compromise between the old EN ISO 13790:2008 and Trnsys, since they allow for a more accurate evaluation of energy consumption than the former, while being less onerous than the latter. In the present work, EN ISO 52010-1:2017 is analysed for the first time and an alternative calculation procedure is proposed. These two algorithms are then compared with two other irradiance splitting methods implemented in Meteonorm and Trnsys code. In order to test performance and limits of the different calculation algorithms, we make a comparison among such methods on five European cities characterized by different climatic characteristics. Results show that the model implemented in EN ISO 52010-1:2017 overestimates the diffuse solar irradiance on horizontal plane for all the considered locations, while the proposed procedure and those implemented in the Trnsys and Meteonorm softwares show similar results. Using Trnsys algorithm as a baseline, the proposed calculation algorithm gives the best approximation among the considered models for what concerns the direct, diffuse and global irradiance on vertical surfaces exposed to south, east and west.

According to Italian regulation, the Ministerial Decree of 11 October 2017 about Environmental Criteria, reference values for acoustic indoor quality descriptors in public buildings are imposed. Regarding school environments, indoor acoustic quality targets refer to reverberation time, clarity, and speech intelligibility, whose representative acoustic descriptor is the speech transmission index (STI). This paper presents pyeSTImate, a Python-based tool for speech transmission index prediction in lecture rooms. The tool returns fully simulated results from the dimensions and material characteristics of classrooms with parallelepiped geometry and without limitations in size. Extensive experiments have been conducted with different simulation methods, evaluating the accuracy by comparison with in situ measurements selected from primary, secondary, and university classrooms in school buildings of the Marche Region in Italy. The combination of simulated speech transmission indexes with a prediction method based on an artificial neural network has also been evaluated. The analysis of the performance demonstrates the computational robustness of the tool that enables its use for the analysis of existing rooms, as well as for the renovation and design of new spaces.

In hot-humid climates, porous external surfaces of the buildings with high water sorption capabilities could contribute to the surface temperatures reduction through the release of latent heat by evaporative cooling. On the other hand, compact and low permeable finishing materials could have mechanical and durability benefits respect to the underlying supports, for example reducing the permeability to degrading agents. In this paper, the properties of lime base coat renders with pore modulating additives (sepiolite and colloidal nano silica) have been surveyed to evaluate their effectiveness in water absorption, thermal performance, and the fulfilment of mechanical requirements for the application on the external side of the walls. A traditional lime–sand formulation was taken as reference. After preliminary tests on workability and shrinkage, the optimal mix designs were selected and the samples were subjected to several mechanical and thermo-hygrometric tests, before and after accelerated aging. The results allowed demonstrating that the use of sepiolite in substitution of sand, enhances the render ductility, thermal resistance and water uptake but worsens its mechanical stability, increasing the shrinkage effects and slightly reducing the ultimate strength values. The addition of colloidal nano silica, either to lime–sepiolite or to lime–sand renders, fails to produce any improvement in their either physical or mechanical behavior. Mixed formulations (lime–sand with sepiolite and nano silica) behave as simple lime–sand solutions, showing optimal compressive and flexural strength but reduced water uptake capabilities. This demonstrates that the presence of sand prevails in the performance of the render, and that the adoption of other additives doesn’t worth the cost for the benefit presented.

The behavior of lightweight cement-based and alkali-activated mortars after exposure to temperatures of 500, 750, and 1000 °C was compared. In cement-based mortars, cement was partially replaced (40 vol%) by several refractory fillers (coal fly-ash, biomass fly-ash, cocciopesto, metakaolin). In alkali-activated mortars, metakaolin was partially substituted (0, 25, 50 wt%) by coal fly-ash. The substitution of cement by 40% metakaolin and the substitution of metakaolin by 50% fly ash enhances the resistance to high temperatures of cement-based and alkali-activated mortars, respectively. After exposure to 1000 °C, the high residual compressive strength of cement-based mortars with metakaolin is due to the formation of new crystalline species, whereas in alkali-activated mortars is due to their high densification.

An experimental study was conducted to examine the energetic and ergonomic impacts of an optimized mechanically controlled ventilation system, implemented on the partition wall between a hyper-insulated test building and the attached sunspace, to overcome most of the inherent limitations of a purely radiative heat transfer in presence of very low thermal transmittance envelope. The system comprised two vented holes (at floor and ceiling level), piloted by a smart controller on the basis of the temperature difference between the two air volumes. The threshold was progressively reduced from 2 °C to 0.5 °C to ameliorate the energy performance without trespassing the comfort boundaries. Calls for extra heating from the active technical system (electric radiators) were thus minimized, regardless of the climatic conditions: the energy consumption (normalized over the indoor-outdoor daily average temperature difference and over the daily mean solar irradiation) decremented by 36% and 66% respectively compared to the 1 °C and 2 °C configurations, which, in turn, exhibited similar performance. The ergonomic penalty due to thermal overshooting was statistically acceptable. The outcomes were compared to those of a previous monitoring run on the same case study, with 20% less glazed surface: the new configuration more than halved the energy expenditure. Finally, the albedo of the surrounding materials was shown to be a key-player: even under extremely cold and overcast conditions, the sunspace temperature rose up to 40 °C when fresh snow layered all around the perimeter. Further investigation could support broadening the spectrum of potentially efficient applications.

An experimental study was conducted on a hyper insulated building coupled with a sunspace, to investigate the role of the major design parameters (depth, glass percentage and typology, etc.) and mechanically controlled convective transfer (VMC) on the energy performance. Based on 132 dynamic simulations, a modifiable sunspace was built on the sun-exposed side of a nZEB mock-up in Central Italy and monitored via an extensive sensor network. The conditioning system tracked the seasonal set point via a bang-bang controller, while the VMC was governed by a bespoke temperature-driven logic. In a previous run, irradiative and combined irradiative-convective modes were tested on a 30% glazed sunspace: VMC was found to dump the daily energy consumption to -27%. Then; a second monitoring campaign compared the 30% and 50% configurations. The former guaranteed very stable indoor conditions (20.1±0.3°C), yet the latter still preserved global comfort at a remarkably lower (-40%) energy expenditure.

In the Mediterranean climate, indoor overheating and, thus, excessive use of cooling systems represents one of the main problems both for the occupants’ health and energy consumption. In order to limit this problem, an appropriate design or energy retrofitting of the building envelope is of utmost importance. The predominance of massive buildings in the Italian territory and the need to comply with Italian regulations often leads technicians to not optimal energy saving solutions. To this purpose, this experimental research was conducted on a mockup building, located in Fabriano and characterized by high thermal mass walls (W0) and two different external insulating systems: Cork based lightweight plaster (W1) and Extruded polystyrene foam panel (XPS) (W2). Furthermore, a virtual model in TRNSYS, a transient simulation software, was used to compare analytical and simulated values. Results show that W2 undergoes a higher level of thermal stress than W1, due to higher peaks in the external surface temperature and larger fluctuations in daily temperature. Therefore, a high value of thermal resistance of the external insulation and low value of external areal heat capacity on a massive building causes external surface overheating problems, thus, not representing the optimal construction solution.

Background:The growing interest for the energy efficiency of building technologies has led the construction sector towards the adoption of Opaque Ventilated Facades (OVFs) as high-performance solutions for building systems.Objective:The aim of this study is to determine the optimal thermal inertia of the outer surface of ventilated facades with respect to the indoor comfort and the reduction of the outdoor overheating.Method:An experimental study was carried out in Central Italy (Mediterranean climate), by comparing the thermo-physical performance of three opaque ventilated façades, characterized by different positions of the mass (hollow bricks) within the air cavity. One has no mass and is enclosed by a Lightweight (L) cladding; one has an Internal Mass (IM) right adjacent to the insulation layer and an external lightweight cladding; the last one has an External Massive cladding (EM). The three prototypes (L, IM and EM walls), were installed on a test room and simultaneously monitored in the summer season.Result:The experimental outcomes demonstrate that the EM wall outperforms the others in terms of cooling efficiency, as the incoming heat fluxes towards the indoors are considerably reduced. Moreover, such a configuration led to the lowest surface temperatures on the outer slab, thus contributing to the mitigation of the external environmental overheating.Conclusion:Overall the External Mass (EM) solution was found to be the best choice, being beneficial for mitigating the outdoor surrounding temperatures and enhancing the buoyancy-driven ventilation.

Virtual Reality application in holistic investigations for energy and cost-saving building design, aimed at humans’ well-being and performance, is still emerging and needs validation. In this study, tests in real and virtual scenarios of an office room were performed, investigating the impact of three walls colours (red, white, blue) and two indoor air temperatures (17–22 °C) on 23 participants’ work productivity (through a proofreading task) and thermal and visual sensations (through surveys). The first goal was the comparison of the results obtained in the real and virtual settings; the second one the assessment of the effect of walls’ colour and temperature levels on the mentioned variables in each environment. Statistical analyses were then performed “between groups” (Wilcoxon and t-tests, among datasets of the two environments) and “within groups” (ANOVA and Scheirer test, within each environment). The study revealed no statistically significant variations in productivity and sensation votes, thus supporting the suitability of VR as a proper research technology in this domain. The study also demonstrated no statistically significant effects of colour and temperature on productivity and comfort results within the tested settings. Future investigations should involve a wider range of temperatures and colours and address a wider subjects’ sample.

This paper addresses the potential benefit achievable via model-based, predictive control of the AC system in overheated buildings with large glazed facades. A sick building in Italy (and more specifically a protractedly and intensely sunlit office on the south-exposed, fully-glazed facade) was selected as case study. It was monitored over a week in December. The sensor network mapped the indoor climatic conditions, the surface temperature distribution on the glazed facade and the thermodynamic parameters of the air inlet from the 3-speed fan coil unit serving the room (originally in manual mode). The MPC relied on a grey-box model of the room’s thermal dynamics, built on a short-term monitoring dataset (4-day-lasting collection in November) and tuned during the first day of testing. Its ergonomic and energetic performance was assessed on the two days of maximum and minimum solar radiation. Considerably high operative temperature persisted all over the period of observation. However, while in free running the room reached peak values of almost 28 °C, during the operation of the MPC the setpoint value of 24 °C was never exceeded by more than 2 °C. Indeed, the offset stayed within ±0.5 °C for the 95.8% of the time on the sunnier day and for the 60.8% on the cloudier day, while the PMV remained within the ±0.5 range for the 85% and the 80% respectively. No local discomfort from vertical gradients or drafts occurred. Furthermore, the energy consumptions were remarkably contained since the fan operated at minimum speed for nearly the 80% of time.

This research paper collects the outcomes of an experimental study focused on the energy benefits achieved by coupling an energy efficient building with a sunspace in winter season and Mediterranean climate. Acting as passive Solar heating elements, sunspaces are intended to be a valuable tool among sustainable and energy-efficient constructive and/or retrofitting strategies. In order to assess the energy saving potential of the above-mentioned coupling and relate it to the main design parameters, two operative steps were carried out: the numerical step allowed different simulated configurations to be evaluated in order to identify the optimal one from an energy perspective and physically realize it; the monitoring phase served the double purpose of calibrating the simulation model and provide on-site validated data for subsequent assessments and comparisons. Three main sunspace configurations were tested: irradiative single-glazed, irradiative double-glazed and convective double-glazed. The convective double glazed configuration was found to outperform the others since the daily energy consumption reduction exceeded the 27% (compared to the irradiative, double glazed counterpart) for all weather conditions. Besides, the activation of a mechanical ventilation system was slightly counterproductive in terms of discomfort phenomena since a less stable indoor air temperature was guaranteed. Comparing the two irradiative configurations, it was found that the addition of an extra glass layer was responsible of a quite constant reduction of 1 kW h/day, thus increasing the percent heating energy demand saving achieved through the insertion of the sunspace from approximately 3,3%–8,7%, while minimizing indoor air temperature fluctuations too.

One of the major challenge facing the achievement of nZE standards in existing buildings is the economic issue: the evidence of monetary gains of energy savings facing high investment costs seems still rather limited to the investors’ eyes. In this context, LCC methods have gained much importance in recent years. However, they present a limitation due to the notable simplifications and hypothesis usually made for input parameters that may affect the results. In order to overcome this limit, this work suggests a probabilistic LCC based on uncertainty and sensitivity analysis via Monte Carlo methods and illustrates it through a building case study under several retrofit scenarios sighting the target nZE. The methodology allows investigating the economic effectiveness of alternative measures, giving insight into possible ranges of the economic indicator related to a specific design option. The analysis is focused on a micro-economic dimension and based on the availability and reliability of inputs data and on their proper characterization with Probability Density Functions. Variance-based methods for sensitivity analysis are employed to establish the most influential parameters on output uncertainty. The paper demonstrates the potentials of a probabilistic LCC in providing a more realistic decision support about investments for energy efficient projects.

The aim of the study is to verify the actual performance of a super-insulated wooden envelope in a residential building located in a hot dry summer temperate climate and to optimize its thermal behavior favoring a dynamic interaction with the indoor environment. The method involved an integrated strategy between monitoring and calibrated simulations on experimental data and the simultaneous analysis of several aspects such as energy performance ( EnergyPlus software), comfort (dynamic analysis with Fanger’s PMV comfort model) and environmental-economic sustainability (LCA analysis with SimaPro software). Parametric analyses were carried out to generalize the results to various usage patterns of plants and passive cooling techniques and to several climate zones. The study highlighted the presence of overheating phenomena and demonstrated that this problem can be solved or reduced through the adoption of appropriate passive strategies, such as massive inner linings combined with natural or hybrid ventilation. Appropriate values of internal areal heat capacity and decrement factor will configure comfortable and energy efficient solutions. In temperate climates the optimal solution, namely the adoption of a 12 cm thick solid brick (or double dry clay panel) and natural ventilation, reduces the discomfort levels of 30–50%. In hottest periods of extreme climates the best solution, namely CMV + free-cooling combined with internal lightweight plaster, only slightly reduces the overheating with a 6% reduction of discomfort.

Thermal comfort and indoor air quality in school classrooms are essential requirements to promote students’ productivity and reduce health symptoms. This paper presents the development of an automatic system for window openings, based on thermal comfort and indoor air quality correlations. The research was carried out in two adjacent classrooms. The initial phase aimed at assessing environmental conditions in classrooms, testing objective and subjective comfort models and establishing trigger parameters for window opening events; the second phase regarded the implementation of an adaptive control algorithm in an automatic system piloting windows with the aim of maintaining a satisfactory environment both in terms of IAQ and thermal comfort. The main results show that: (1) the IAQ is a relevant issue in school classrooms, because students usually suffer high CO2 levels; (2) the stronger driving force for undertaking adaptive actions is thermal comfort, while the need to improve the air quality is a secondary constraint; (3) the mechanized system ensures a good quality in terms of IAQ, thermal comfort and users’ satisfaction.

An experimental study was conducted to improve the comfort and liveability of urban open spaces during the hottest months of the summer by implementing an overhead water mist cooling system. The campaign was conducted in two different Italian urbanscapes (Ancona and Rome, representative of Cfa and Csa climates) one after the other. Monitoring data and comfort questionnaires were combined to extract useful information by means of statistical tests, regressions and data mining algorithms and, ultimately, to delineate design and operating guidelines to maximize people's satisfaction with the misted environment. The cloud of droplets reduced the temperature and the UTCI by 8.2 °C and 7.9 °C respectively, against a 7% mean humidity premium. The vertical cooling and humidification profiles obeyed a Lorentzian distribution, peaking within approximately 0.5 m of the injection. The severe overheating experienced outside of the cooled areas evanished under the spray, with 67% (Ancona) to 90.6% (Rome) of respondents reporting only slight bending from thermal neutrality. Perception and preferences towards solar radiation, humidity level and wind all improved within the droplets mist. In terms of comfort-oriented, optimized design criteria, the system proved to work best with a dominant and steady light breeze (1–2 m/s), in highly irradiated sites and suspended at 1.2–1.5 m above the average height of users.

Growing interest is recently being focused on the role played by the platelets in favoring hepatocellular cancer (HCC) growth and dissemination. The present review reports in detail both the experimental and clinical evidence published on this topic. Several growth factors and angiogenic molecules specifically secreted by platelets are directly connected with tumor progression and neo-angiogenesis. Among them, we can list the platelet-derived growth factor, the vascular endothelial growth factor, the endothelial growth factor, and serotonin. Platelets are also involved in tumor spread, favoring endothelium permeabilization and tumor cells' extravasation and survival in the bloodstream. From the bench to the clinics, all of these aspects were also investigated in clinical series, showing an evident correlation between platelet count and size of HCC, tumor biological behavior, metastatic spread, and overall survival rates. Moreover, a better understanding of the mechanisms involved in the platelet-tumor axis represents a paramount aspect for optimizing both current tumor treatment and development of new therapeutic strategies against HCC. Growing interest is recently being focused on the role played by the platelets in favoring hepatocellular cancer (HCC) growth and dissemination. The present review reports in detail both the experimental and clinical evidence published on this topic. Several growth factors and angiogenic molecules specifically secreted by platelets are directly connected with tumor progression and neo-angiogenesis. Among them, we can list the platelet-derived growth factor, the vascular endothelial growth factor, the endothelial growth factor, and serotonin. Platelets are also involved in tumor spread, favoring endothelium permeabilization and tumor cells’ extravasation and survival in the bloodstream. From the bench to the clinics, all of these aspects were also investigated in clinical series, showing an evident correlation between platelet count and size of HCC, tumor biological behavior, metastatic spread, and overall survival rates. Moreover, a better understanding of the mechanisms involved in the platelet–tumor axis represents a paramount aspect for optimizing both current tumor treatment and development of new therapeutic strategies against HCC.

The paper is concerned with the practical use of formal techniques to contribute to the risk analysis of a new neonatal dialysis machine. The described formal analysis focuses on the controller component of the software implementation. The controller drives the dialysis cycle and deals with error management. The logic was analysed using model checking techniques and the source code was analysed formally, checking type correctness conditions, use of pointers and shared memory. The analysis provided evidence of the verification of risk control measures relating to the software component. The productive dialogue between the developers of the device, who had no experience or knowledge of formal methods, and the analyst using the formal analysis tools, provided a basis for the development of rationale for the effectiveness of the evidence. (C) 2019 Elsevier B.V. All rights reserved., This work has been funded by: EPSRC research grants EP/G059063/1 and EP/J008133/1: CHI+MED (Computer -Human Interaction for Medical Devices); and NanoSTIMA (ref. NORTE-01-0145-FEDER-000016) financed by the North Portugal Regional Operational Programme (NORTE 2020), under the PORTUGAL 2020 Partnership Agreement, and through the European Regional Development Fund (ERDF). Leo Freitas would like to acknowledge EPSRC Trams2 project for financial support, Andrew Sims for providing access to the dialyser, which was used as our case study and Aleksandrs Baklanovs for doing some of the source analysis as part of an undergraduate project.

Several mature urban climate mitigation technologies have been proposed to date. What mostly hinders their wide implementation is that their efficiency heavily depends on the local microclimatic specificities, since they cannot self-adjust to the environmental changes. This study aims at investigating benefits and impacts of smart logics applied to outdoor cooling, by field testing a web of nebulizers coupled to a bespoke fuzzy controller piloting the pump. The cooling action was tweaked as convenient to maintain comfortable conditions and to avoid energy wastage whenever unneeded. To the best of the authors’ knowledge, this is the first application of fuzzy logic to water spraying systems (or to any other controllable urban climate mitigation technology) targeting comfort and energy optimization. The prototype was field monitored in comparison with the conventional on-off control, in two Italian urban contexts (Cfa and Csa climatic zones) over 15 days in the hottest months of the year. The cooling and humidification action was thoroughly characterized by mapping both the horizontal and vertical profiles and by applying advanced Artificial Intelligence techniques to spot the main environmental drivers. The maximum cooling (measured between the sprayed area and an undisturbed reference) touched 7.5 °C and 6.14 °C in the two locations, respectively. The energy saving achieved under fuzzy control versus the temporized control, was spectacularly high in the wetter and windier location with an average of −51.2% and a maximum of −67.5%. The comfort benefit was also substantial: the temperature never deviated from neutrality by more than ±2 °C, whereas with the on–off, this threshold was surpassed between the 14% and the 20% of the time by even more than 5 °C. The results suggest that smartly controlled nebulization is an energy-efficient and comfort-effective strategy to counteract urban overheating. Furthermore, solar-powered solutions are well suited as proved by the preliminary design estimation we included.

The paper reviews some of the latest researches and future trends in the field of technologies to support sustainable, comfortable and healthy citizens life in the cities of tomorrow. A specific focus is on advanced methods to guarantee comfort and energy efficiency in the built environment, together with the support to the ageing people in their homes. Innovative sensing systems are presented to monitor both the environment conditions and people in a non-intrusive way, thus allowing the implementation of efficient management strategies and new social services. The review presents real case studies properly equipped with comfort measurement systems, sensor networks including physiological parameters or with specific HVAC and construction components to assess the effects on energy consumptions and comfort levels of different control strategies and configurations. In addition, distributed generation technologies installed at final users together with their increasing awareness in energy consumption patterns, result in the “prosumer”: a citizen that simultaneously acts as an aware energy consumer and producer. Based on the achieved outcomes, a discussion about the most promising research lines for citizen-oriented technologies in the cities of tomorrow is finally presented.

This paper investigates and compares the energetic and ergonomic performance of three different control logics (on–off, PID, fuzzy), used to regulate the emission of the heating system of an energy-efficient building. Tests were carried out on an experimental building, equipped with three electric radiators and a sensor network mapping internal, external and surface thermal conditions. The building–technical system ensemble was evaluated in real time for a monitoring period of five/six days of non-occupancy, winter/midseason weather and Mediterranean climate. All controllers were assessed with regard to thermal comfort and energy consumption in order to return an exhaustive scenario of possible strengths and weaknesses. The comparison showed that fuzzy logic, properly configured, outperformed both PID and on/off controllers reducing energy consumption of 30–70% and maintaining thermal dissatisfaction between comfort limits for all the monitoring period.

Mist cooling is a widely known and applied heat mitigation technology, especially in urban settings. Despite this, conceiving the right installation is no trivial matter as scattered and unstandardized is the knowledge on the multiple interrelations with the local microclimate. This paper investigates how the cooling efficiency of a dry mist system depends on the local meteorological trends. An experimental system of 24 overhead nozzles constantly operating at 0.7 MPa, was installed in Italy and monitored for a week in summertime. Temperature and relative humidity underneath the mist were mapped in five locations with a time step of 10 s, together with the main meteorological parameters, measured at an undisturbed location, for reference. Cooling and humidification capacity were characterized as probability density, key summary statistics and relevant confidence intervals with minimal redundancy and minimal distortion. A supervised learning algorithm was used to disclose the sensitivity of the recorded temperature drop to the contextual microclimatic evolution. It was demonstrated that the cooling capacity of the tested system was largely a function of the local wet bulb depression, as instantaneous reading as well as short-term trend. Additionally, solar irradiation and wind speed were found to be negatively and positively correlated, respectively.

In this paper we have investigated how different materials and thermal masses impact on the performance of ventilated facades with narrow cavities, by measuring the variation in terms of heat flows and ventilation efficiency. While geometry has been widely explored, the role of wall composition has received much less attention. To bridge the gap, three real-scale prototypes of ventilated facades were built and tested all over the year on a mock-up in Central Italy: (i) L, with a lightweight external enclosure, as a baseline reference, (ii) IM, with a massive layer enclosed in the gap and (iii) EM, with an external massive cladding. The results demonstrated that the EM solution more effectively mitigated the average surface temperatures (both external and internal), with values of –2 °C and –1 °C in summer and of –3 °C and –0.5 °C in winter, when compared to the L solution. Moreover, in the EM case, the ventilated cavity reduced both the incoming and outgoing heat fluxes, since the outer mass operated as a thermal buffer between the outdoor and the ventilation chamber. Conversely, the presence of an internal mass determined an increase of the heat transfer towards the indoor environment. The position of the thermal mass in the outer layer also increased the air velocity in the gap thus enhancing the stack effect.