Search

Transparent elements of buildings account for most of the variation in the spectrum of transmitted daylight. This behavior has a considerable impact on the luminous quality of the indoor environment, because the light spectral composition affects the perceived color and brightness of the illuminated objects. As a consequence, the effect of light colour and intensity on the behavior and health of the occupants is very important. Among the innovative transparent solutions for buildings, monolithic aerogel is one of the most promising, both in terms of lighting and thermal performance. In this context, the present study investigates the colour rendering properties of monolithic aerogel. For the analysis we employed a machine vision system based on a dome-shape illuminator, a digital camera, a chroma meter, and a colour checker. We evaluated the effect of the aerogel on colour rendering by measuring the RGB and CIE Lab coordinates of the reference colours of the colour checker with and without the aerogel. The results show that, in general, the presence of aerogel tends to shift all the colours towards a blue hue, the maximum variations occurring with dark tones of red, yellow, and green. Finally the Colour Rendering Index Ra was calculated for the examined monolithic aerogel by means of a methodology developed in accordance to the EN ISO 410 standard and CIE standard procedures. The obtained values prove a rather good visual quality of the monolithic aerogel (Ra = 85).

Aerogel is a promising building envelope material that can be used to improve thermal and lighting performance. In monolithic form, aerogels allow visual interaction between the built and outdoor environments, unlike aerogels in granular form. However, the high production cost of large monoliths limits their use. In this work, monolithic silica aerogels were fabricated using tetramethyl orthosilicate as the precursor in a base-catalysed recipe, and a novel rapid supercritical extraction method. The method produces transparent aerogel monoliths in as little as six hours. A 30 × 30 cm glazing sample was constructed from nine 15-mm-thick aerogel monoliths sandwiched between two pieces of 4.7-mm-thick float glass. The glazing sample was characterized in terms of directional and hemispherical optical and visual properties. Measurements were made with an in-house-constructed spectrophotometer equipped with a 75-cm-diameter integrating sphere in the 380- to 2300- nm wavelength range with variable incidence angles. The light and direct solar transmittance are 0.69 and 0.62, while the light and direct solar reflectance are 0.25 and 0.19, respectively. The sample is also characterized by a high general colour rendering index (Ra = 96), allowing indoor visual comfort. Gonio-photometric and directional spectral transmittance measurements show negligible visual distortion and colour variation at different observation angles. The light transmittance of the prototype is lower than that of glazing units present on the market, but about 10% higher than an equivalent unit with granular aerogel. This performance is promising for applications where view through a window is required. However, the size of the samples currently fabricated with the innovative process is limited to 14 × 14 cm and they are characterized by some optical defects that must be removed if the process is to be used for commercial product.

Recycled waste materials obtained from industrial and agricultural processes are becoming promising thermal and acoustic insulating solutions in building applications, their use can play an important role in the environmental impact reduction. The aim of the present paper is the evaluation of the thermal performance of recycled waste panels consisting of cork scraps, rice husk, coffee chaff, and end-life granulated tires, glued in different weight ratios and pressed. Six panels obtained from the mixing of these waste materials were fabricated and analyzed. In particular, the scope is the selection of the best compromise solutions from the thermal and environmental points of view. To this aim, thermal resistances were measured in laboratory and a Life Cycle Assessment (LCA) analysis was carried out for each panel, a cross-comparative examination was performed in order to optimize their properties and find the best panels solutions to be assembled in the future. Life Cycle Analysis was carried out in terms of primary Embodied Energy and Greenhouse Gas Emissions, considering a &lsquo, &lsquo, cradle-to-gate&rdquo, approach. The obtained thermal conductivities varied in the 0.055 to 0.135 W/mK range, in the same order of magnitude of many traditional systems. The best thermal results were obtained for the panels made of granulated cork, rice husk, and coffee chaff in this order. The rubber granulate showed higher values of the thermal conductivity (about 0.15 W/mK), a very interesting combined solution was the panel composed of cork (60%), rice husk (20%), and coffee chaff (20%), with a thermal conductivity of 0.08 W/mK and a Global Warming Potential of only 2.6 kg CO2eq/m2. Considering the Embodied Energy (CED), the best solution is a panel composed of 56% of cork and 44% of coffee chaff (minimum CED and thermal conductivity).

A comprehensive review of aerogel glazing systems is provided, focusing on the main properties of interest in building applications. Both granular and monolithic forms are taken into account, even if only the former is available on the market. Reviewed studies regard the material itself and of the assembled glazing systems are analysed. After a short description of the fabrication process, thermal and optical properties are presented, in order to provide a set of useful data on the most important parameters affecting energy and lighting performance of buildings. Not-energy related aspects, as quality of lighting and acoustic properties are also investigated, being relevant for the successful building integration. Numerical analyses and field studies show the potential of the technology to achieve relevant energy savings with respect to conventional glazing systems, especially in cold dominated climates. Long term performance studies confirm the reliability of the technology, with minor functionality issues to be solved. Costs of aerogel are still considerably higher when compared to conventional glazing units, however the fully developed technology may become competitive with the performance required in a zero energy building perspective.

The excellent thermal insulation properties of aerogel glazing systems make them an interesting building solution, especially in cold climates. When aerogel glazing systems provide less solar heat gain factor, they could be useful in warm and hot regions (such as Tokyo, Rome and so on) because buildings in such areas are often designed to minimize cooling energy demands. If a sort of opaque powder is mixed with aerogel granules, able to stick to each granule and to cover the aerogel surface discontinuously, the mixture can thus reduce solar transmittance, contributing to daylight usage with less glare risks and cooling energy demand reduction, without shade or blinds, keeping as high thermal performance as aerogel. This innovation is examined in the present paper, by presenting the following solution: a double glazing unit with a mixture of silica granular aerogel and hollow silica powder in the gap (AGS), in order to reduce the solar factor. The solution is tested through in-field experimental campaigns and numerical analyses, making available a set of data not found in literature, where mixtures of aerogel and powder were never studied. The air temperatures in the test Room with AGS, especially the peak values, are lower than the ones in the reference one with installed a standard glazing system (SGS). The same behaviour is observed in several experimental campaigns in different seasons: in mid-season 1 the highest differences are of about 6–7 °C, whereas in summer they reach 12–16 °C. Significant differences in terms of illuminance are also observed: the calculated Useful Daylight Illuminance (UDI) shows AGS values 57% higher than SGS, highlighting the aerogel ability to diffuse light and to reduce glare. Experimental data were used for energy analyses of a reference building in Tokyo. AGS outperforms a low-e glazing in terms of heating energy demand: the reduction varies in the 22% (North) − 62% (South) range. The lighting energy demand is quite similar: electricity demand increases in the 3–6% range. Finally, the internal shade on the reference glazing has a significant impact on the estimated energy demand, both for cooling and heating.

In order to reduce the carbon emissions resulting from buildings construction, some non-conventional materials are emerging, especially the ones of natural origin. In this scenario new building components have been developed as thermal insulating panels such as the ones made of wood, straw, and cork. In the present paper a multi-sheet wall was investigated by analyzing the thermal properties of each layer by means of a new experimental apparatus named Small Hot-Box. The wall is composed from the outside towards the inside by a ‘cocciopesto’ mortar, a thick layer of straw, a wooden planking, an air interspace of about 5 cm, and a final raw earth plaster, for a total thickness of about 50 cm. Results showed thermal conductivities in accordance to Literature values both for the wood (0.089 W/mK) and for the straw (0.065 W/mK). For the ‘cocciopesto’ and the earth-based plasters no many Literature data are available: the thermal conductivities are equal to 0.92 and 0.98 W/mK respectively. The total thermal transmittance of the wall was estimated by combining the results and considering the real scale thickness of each layer; it is about 0.15 W/m2K.

Students spend a lot of time at school, highlighting the great importance of providing comfortable conditions in educational buildings. Indoor environmental conditions are also related to student productivity and well-being, but Literature reviews mainly examine the effects of single parameters on human comfort, lacking in the evaluation of comfort combining different aspects, such as thermal, acoustic, and visual ones. The aim of the paper is to propose an index for the evaluation of the environmental comfort tacking into account thermal, acoustic, and lighting conditions. Seven university classrooms were investigated; measurements of environmental factors were performed including thermal, acoustic, and lighting parameters. Subjective evaluations were also carried out through survey questionnaires purposely elaborated. Three single indexes were proposed basing on the strongest correlation between questionnaire's answer and experimental results: a Predicted Mean Vote Index for the thermo-hygrometric conditions, a Sound Index for the acoustic comfort, and a Visual Index for the lighting conditions. All the indexes are dimensionless and normalized in a 0–1 range: values next to 1 indicate good comfort conditions and values next to 0 indicate bad comfort conditions. On the basis of different weights given for the three aspects, a final combined comfort index was calculated for each classroom and compared with questionnaires results, in order to assess the methodology.

Ventilated walls were adopted in the past in order to protect buildings from moisture and weathering. Today their main use is for energy purposes. In this paper, a new kind of ventilated wall made of traditional and local materials was studied, with the support of a local brick producer Company. A first prototype of ventilated wall was built between two test chambers at the Laboratory of the Department of Engineering – University of Perugia, and the heat transfer and the velocity profile developed within the air gap were investigated in controlled condition, by considering both unventilated and ventilated configurations obtained opening and closing some ventilation holes. The laboratory experimental campaigns were carried out in steady state, in order to study the air motion field from a fluid-dynamic point of view. The ventilation into the air gap was also investigated by means of CFD simulations; different turbulent models and one radiation heat transfer model were tested and validated with the collected data during the laboratory experimental campaign, in order to check the best solution able to correctly simulate the velocity profile in the masonry wall. The validated CFD model was therefore used for the optimization of the ventilation openings, by studying the velocity profile into the air gap. The best solution was then chosen and a new prototype of the ventilated wall was built in a new school gym; in order to investigate the thermal behavior of the developed wall, an intensive experimental campaign is still in progress.

In building applications, recycled waste materials are becoming promising acoustic absorbers and thermal insulating solutions in order to reduce the environmental impact. The aim of the research is to evaluate the thermal, acoustic, and environmental performance of recycled waste panels consisting of rice husk (RH) produced by gluing and pressing the raw material. Its acoustic and thermal performance were compared with the ones of six panels composed by other recycled materials (cork scraps, end-life tires, coffee chaff, waste paper, textile fiber mats, wool fiber scraps), assembled with similar techniques. Thermal resistance of RH is equal to 0.59 m2K/W, in the same order of magnitude of many traditional systems. Sound absorption coefficients were measured by means of the impedance tube. All the panels present acoustic absorption comparable with traditional ones (peak values 0.87–0.99). RH peak value is 0.87, while the maximum values are obtained for cork and wool fiber scraps (1 and 0.97 respectively). Life cycle analysis, performed in compliance with ISO 14040 showed the best environmental performance for the production of 1 m2 of RH and coffee chaff panels. Taking in account their acoustic and thermal behaviour, the wool fiber scraps presents a very good performance.

8th International Conference on Sustainability in Energy and Buildings, SEB 2016 The influence of granules size in silica aerogels is experimentally investigated in terms of thermal and acoustic performance characteristics. The transmission loss (TL) is measured at normal incidence in a traditional impedance tube, whereas the thermal conductivity (?) is evaluated using a Hot Plate apparatus, setting up an appropriate methodology, due to the nature of the sample. The results reveal that the small granules (granules size in the 0.01-1.2 mm range), which have the highest density, have the best performance both in terms of thermal and acoustic properties. Depending on the granules size, ? varies in 19-22 mW/mK range at 10°C, whereas a TL equal to 13 dB at about 6400 Hz for 20 mm thickness is obtained for small granules. © 2017 The Authors.

Biomass is a fundamental renewable resource to develop sustainable energy conversion systems with low environmental impact. The design of biomass pyrolysis, gasification, and combustion facilities requires a particular attention at kinetic aspects. A coffee production residue such as coffee silver skin, which is the main product of the coffee roasting industry, is very suitable for thermochemical conversion, being already dry and containing compounds like the ochratoxin which does not allow its use in the production of biochemicals. In this work, thermal degradation tests of coffee silver skin are made under inert conditions at various heating rates (5, 7, 10, 15 °C/min) and a proper kinetic model was considered in order to quantify the activation energy (Eα). The variation of Eα with the conversion rate (α) was higher than 30%, showing that the process is kinetically complex and the kinetics cannot be described by a single-step model, according to the International Confederation on Thermal Analysis and Calorimetry. For this reason, a multi-step model and an analytical approach were used. This involves the deconvolution of the individual peaks of each pseudo-component from the overall differential kinetic curves, followed by the application of a model free-isoconversional method to the separated decomposition steps. The determination of the reaction mechanism f(α) of each sub-component (pseudo-cellulose P-CL, pseudo-hemicellulose P-HC, and pseudo-lignin P-LG) was performed by using both the Master-Plots method and the Energy Compensation Effect. The pre-exponential factor, the enthalpy and the Gibbs free energy were also evaluated in order to investigate the pyrolysis characteristics. A second order model mechanism was obtained for P-CL and P-HC, whereas no clear mechanism was found for P-LG when α > 0.5.

Indoor comfort, energy demand, carbon emissions and the cost of maintaining a building vary according to the structure of the building and the behaviour of its occupants. The main goal of this research is to analyse the bioclimatic potential of different Malagasy climatic zones. In addition, this study analyses and compares energy consumption and carbon emissions in six building categories commonly found in Sub Sahara African cities designed to be placed in thirteen cities unequally distributed in the six climatic regions in Madagascar. To reach this objective, hourly weather data for the last thirty years were analysed for two seasons. At the same time, the adaptive comfort model defined by the ASHRAE 55 served as a reference for the evaluation of different passive design potentials. The results showed that in the sub-Saharan or hot zone, the range of comfort varies according to with the geographical position and that the number of hours of thermal comfort and acceptability is in the majority of the cases outside the range recommended in the international standards (CIBSE, ASHRAE and ISO). Finally, it was concluded that Madagascar Island, such as other countries, should build their own standard due to the average demand for cooling energy increases every year up to 3.4% in the coastal towns and more than 80% of carbon emissions can be reduced in hospitals in Madagascar, as well as in Sub-Saharan Africa, by increasing the maintenance cost between 7% and 10% of the total life cycle cost of a building. In Madagascar Island, the building Life cycle cost ranges from 12% to 14% for the construction cost, 0–1% for the renovation cost, 36%–73% for the energy cost, 2%–3% for the maintenance cost on the whole LCC.

Glycerol is a co-product compound of biodiesel production with an interesting heating value. In this work pyrolysis kinetic parameters for a pellet made with a mass fraction of 90% sawdust and a mass fraction of 10% glycerol are derived through thermogravimetric analysis. A new parallel reaction scheme with four components (cellulose, hemicellulose, lignin and glycerol) is adopted and the kinetic triplet for each component is derived using a model fitting approach applied to this particular kind of pellet. The isoconversional method Kissinger-Akahira-Sunose is employed both to provide initial values for model fitting simulations and to check final results. Results show that activation energies and pre-exponential factors are respectively: 149.7 kJ mol−1 and 1.98*1011 s−1 for hemicellulose, 230.1 kJ mol−1 and 1.84*1017 s−1 for cellulose, 154.3 kJ mol−1 and 5.14*109 s−1 for lignin, 74.5 kJ mol−1 and 2.17*105 s−1 for glycerol with a first reaction order for all components, except for lignin (n = 2.6). Through evolved gas analysis it was demonstrated that the thermal degradation of glycerol contained in the pellet can increase hydrogen content in pyrolysis gases.

The energy efficiency of buildings can be evaluated by using the methodology provided by European regulations; however, this method required a lot of information which is generally not available for the existing buildings. In this paper an alternative method for the energy efficiency investigation of buildings is proposed and tested by means of Artificial Neural Networks (ANNs); an existing building built in 1990 and located in Perugia was chosen as case study and it was investigated by adopting both the mentioned approaches. An experimental campaign was also carried out in order to implement and validate the 3D model developed in TRNSYS. Results showed that the indoor air temperature trend simulated with ANN is closer to the measured data than the one simulated with TRNSYS, with lower mean error and MSE values. The energy consumption simulated with ANN is slightly higher than the one returned by using TRNSYS code of about 20 kWh/m 2 year (difference lower than 7%). In agreement with the results, the proposed method can be considered as an alternative tool that can be used for the thermal-energy investigation of existing buildings, with important money and time saving.

Theatres are a very complex environment where thermal comfort is difficult to control. They frequently operate at high occupancy level and tend to have high sensible and latent heat loads. An application of the neutral comfort temperature methodology is proposed to analyze this particular kind of building. Thermal-hygrometric parameters defined in ISO 7730, Ashrae Standard 55/2004 and ISO 10551, were measured at carefully selected locations in the occupied zone within the auditorium in the Fraschini theatre, in order to ensure a good representation of human exposure to thermal comfort. In addition, a subjective evaluation was achieved by the distribution of a dedicated multiple response questionnaire. More than 400 questionnaires were analyzed, comprehensive of information for the application of the traditional static and adaptive model. When heating system is on (1st and 2nd survey), thermal stratification is really relevant in the theatre (air temperature runs from 23 °C in the stalls area to 30 °C in the upper order), while when the theatre is in naturally ventilated, the thermal stratification is not relevant. An application of a new thermal comfort evaluation method is here proposed by means of the calculation of the neutral comfort temperature with both the analytical and adaptive methods. . The methodology was also applied to data acquired in 9 different open space offices, where a total amount of 846 people were interviewed. Results showed that the method is applicable to both theatres and open plan offices and could provide a simple tool to quickly evaluate thermal comfort conditions.

A simplified algorithm using an artificial neural network (ANN, a feed-forward neural network) for the assessment of the predicted mean vote (PMV) index in summertime was developed, using solely three input variables (namely the indoor air temperature, relative humidity, and clothing insulation), whilst low air speed (

Olive tree leaves, an abundant agricultural by-product without enough industrial market outlets, are presented in this study as a relevant resource of available carbohydrates to be chemically treated for monomeric sugar production. Characterization of two main granulometric fractions is the starting point for testing the specific effect and the relevance of three main factors (time, temperature, and sulfuric acid concentration) on diluted acid hydrolysis with respect to oligosaccharides, simple sugars, and fermentation inhibitory compounds production. The selected conditions (100 ∘ C, 90 min, and 6% w/w H 2 SO 4 ) to perform the small scale hydrolytic process, considering response surface methodology (2 3 factorial design with center points), implied production of acetic acid and hydroxymethylfurfural in concentrations not exceeding 1.10 kg m &minus, 3 and 0.25 kg m &minus, 3 , respectively. Thus, these experimental conditions were the reference framework to evaluate the effect of a meaningful scaling stage in a hydrolysis reactor, considering kinetic parameters based on hydrolysis rates and D-glucose and D-xylose generation.

The paper deals with the experimental characterization of double glazing units with granular aerogel in cavity at laboratory and pilot scale. In the laboratory investigation, three granule sizes and three aerogel layer thicknesses (10–35 mm) were considered. Light transmittance is in the 0.41–0.75 range (the highest values for the highest granule size and the minimum thickness). The U-value is 1.5 W/m2 K with 10 mm aerogel, whereas it decreases to 0.5 W/m2 K when considering 35 mm of aerogel, regardless of the granules size. After a systematic characterization, aerogel with large granules, the most common on the market, was chosen for an investigation at pilot scale. A window composed of two 6 mm clear float glasses and 15 mm aerogel in gap was tested in an experimental field with two boxes, in comparison with a conventional window. Aerogel sample allowed a reduction in the peak value of the indoor temperature of about 8–9 °C during sunny days, while similar values were achieved in the two test boxes during the night.

A good ventilation is important to improve indoor air in buildings. In Sub-Saharan Africa regions and other countries, both health and productivity are indeed elements depending on indoor comfort. The purpose of this research is to suggest a new thermal comfort approach based on subjective responses of occupants and mathematical models. There is a lack of data about indoor comfort in residential buildings in the tropical islands of Indian Ocean and the aim of the research is to propose guidelines for more comfortable constructions in Madagascar and other countries of the Indian Ocean. Experimental and subjective data were collected in 67 traditional habitats and 25 public and private schools, located in 25 districts of urban communes in the Northern Madagascar. Mathematical modelling was based on Rohles approach. At total of 992 questionnaires were collected and analysed during rainy and dry seasons. The results showed that traditional buildings were more comfortable than schools. Comfort temperature varied from 24.6 to 28.4 °C during both seasons in residences and schools. When the indoor air temperature varied in the 24.5–27.5 °C range, more than 80% of peoples were satisfied.

Climate change continues to remain the main concern of all nations, and the adverse effects of this problem are enormous. This research was aimed to study the variation of outdoor climate in some regions of Madagascar, and also the assessment of impacts and vulnerabilities related to global warming. Toward this end, the daily data relating to the last 44 years have been studied. A first analyse has been carried out with several GCMs models, and scenarios(A2, A1B and B1), then RCM models associated to Representative Concentration Pathway(RCP) scenarios(RCP2.6, RCP4.5, RCP 6.0 and RCP 8.5). Chi-square Pearson tests and probabilities have been assessed to compare observed values and generated values. A significant values showed(P

Polycarbonate panels could be considered as a suitable and cheap solution for walls, roofs, and sheds in non-residential buildings and, at the same time, granular silica aerogel is one of the most promising nano-materials for energy saving in buildings. In the paper, three types of advanced multiwall PC panels (thickness 16, 25, and 40 mm) with translucent granular aerogel were investigated by experimental (thermal and optical) and numerical characterization. By comparing thermal performance of air and aerogel-filled PC systems, it can be noticed that the impact of the aerogel is remarkable: the reduction in U-value is 46%-68%, depending on the aerogel layer thickness. U-value is 1.4 W/m2K for the 16 mm thickness sample and it is 0.6 W/m2K when the thickness increases up to 40 mm. The systems keep their performance in horizontal position, when they are used as roofs. Light transmittance is 0.61 and 0.42 for 16 mm and 40 mm respectively and the reduction with respect to air-filled panels is acceptable (15%) for 16 mm and significant (40%) for 40 mm thickness. The aerogel has also a remarkable impact on the reflectance spectrum, especially between 400 and 1400 nm. The solar factor is 0.58 for 25 mm thickness, quite similar to the low-e glazing one. Finally, energy simulations for a case study showed that aerogel-filled PC systems outperform conventional double glazing systems both for heating and cooling energy demands. However, when compared to low-e glazings, the benefits of the translucent material (also considering the highest thickness) in the interspace are lower for heating and negligible for cooling energy demands. The aerogel-filled polycarbonate systems could be a valid solution for non-residential buildings, enhancing the thermal performance and the light control of the building envelope, especially when they are used as roofs. © 2018 Elsevier B.V.

Silica aerogels are thermally and acoustically insulating and can offer advantages in building thermal applications. They come in granular (multiple small pieces) and monolithic (single piece) form. Granular aerogels are relatively easy to produce and can be incorporated into large window systems. Large monolithic aerogels are more difficult to produce, but they offer superior optical and thermal performance. The aim of this paper is to experimentally investigate the acoustic properties of monolithic aerogel samples fabricated using a rapid supercritical extraction method. The acoustic absorption coefficient (α) and the transmission loss (TL) were measured at normal incidence in a traditional impedance tube in the 100–5000 Hz frequency range, for three thicknesses, from 12.7 to 25.4 mm. Good acoustic performance was achieved: 12.7-mm-thick cylindrical monoliths have a peak acoustic absorption coefficient of 0.88 at ∼1500 Hz. When the thickness increases, α decreases (to 0.78 and 0.54 for 19-mm and 25.4-mm thick samples, respectively), with peaks at lower frequencies (1300 and 1100 Hz). The transmission loss increases with aerogel thickness with values as high as 10–15 dB in the 100- to 1600-Hz range. When compared to granular aerogels, the monoliths have TLs that are 5–7 dB larger in the 100- to 1600-Hz range. To further compare performance, small glazing packages were fabricated from glass panels with air, granular, or monolithic aerogel in the interspace. The TL was evaluated and found to be in the 35- to 45-dB range for all samples. The monolithic aerogel glazing had the highest TL, particularly in the 200- to 1000-Hz range. Based on these results, we estimated a 3-dB increase in the sound insulation index for the glazing system with a monolith when compared to the glazing system with air, and a 1- to 2-dB increase when compared to the granular aerogel glazing. This study demonstrates that the use of transparent monolithic silica aerogel in the interspace of conventional glazing systems would result in significant improvement in noise insulation.

Among lignocellulosic residues, peach tree prunings are widely abundant in Italy, due to an extensive production and a high yield of prunings per cultivated hectare; thus, it represents an interesting feedstock for no food derived ethanol. In the whole production process, the pretreatment is the most critical step from technical and economic point of view. In this work peach tree residues were submitted to alkaline pretreatment, in order to maximize the fermentable sugar recovery and thus to maximize the theoretical etOH yield evaluating the best operative conditions in terms of NaOH concentration, temperature, and reaction time. The analysis is carried out by means of Response Surface Methodology approach, in order to optimize the pretreatment step. The optimal predicted conditions to perform the process were NaOH concentration = 0.200 mol dm-3, temperature = 125 °C and reaction time = 35 min, that allowed to obtain a theoretical ethanol yield of 223 L t-1 of dry peach tree pruning. This theoretical yield can be judged satisfactory in the context of forest and pruning biomass and it could be further increased by a future scale up from laboratory to pilot scale.

Questionnaires are an important tool for analyzing the thermo-hygrometric, acoustic, and lighting conditions of indoor environments. In the present work thermal, acoustical, and visual conditions were investigated through both subjective and objective measurements carried out in 7 classrooms at the University of Pavia, Italy. Measurements of the main descriptors of thermal, acoustical, and visual comfort were carried out and new specific questionnaires were purposely developed, in order to investigate the students' perception on acoustic and lighting comfort and to analyze which are the subjective parameters most correlated with the experimental results. Both 7-value and 13-value scales were provided to the occupants for the thermal comfort evaluation and no significant differences in the results were found. Among all the acoustic comfort questions, the ones related to background noise present the highest correlation. Other questions were selected considering the intelligibility - comprehension and the overall assessment of the auditory environment in the classrooms. Classroom 5 is the worst in terms of acoustic conditions and it is confirmed by the correspondent indexes named IBN and ISQ. The analysis of the lighting questionnaire showed that the average measured illuminance value has a high correlation with the perceived visual comfort. The classrooms annoying glares have a strong relationship to the classroom excessive light contrasts and a good correlation with the measured illuminance values. Among the acoustic and lighting questionnaires, ten questions with the best correlation with the experimental results were chosen and ten indexes were proposed, in order to describe the comfort conditions.

In this paper, the second generation pathway for bioethanol from hornbeam residues was investigated, in order to define the optimum operative conditions of steam explosion pretreatment and subsequently enzymatic hydrolysis maximizing the glucose amount for fermentation process. The whole experimental procedure was designed and analyzed by Response Surface Methodology, a statistic multivariate model that allows to investigate the effect of different parameters on a process and define the optimum values of these variables to optimize the response. The glucose yield from enzymatic hydrolysis was maximize as function of three variables: the severity factor of pretreatment (log R0), the total solids (TS%) of the enzymatic hydrolysis and enzyme loading (EL%) in the enzymatic hydrolysis stage. The Design of Experiment (DoE), based on central composite model, was characterized by 17 tests, varying the variables at five levels, log R0 (3.92, 4.08, 4.31, 4.54, 4.7), TS% (5, 7, 10, 13, 15), EL% (5, 7, 10, 13, 15). The optimization allows to define the best operative condition that is log R0 = 3.97, TS% = 6, EL% = 15 which leads to an overall fermentable sugars yield of 67.8% respect to the initial sugars content in the raw material that corresponds to a theoretical amount of producible ethanol of 251 L/ton dry raw material.

Natural materials, such as straw bale and earth, have substantially less embodied energy than processed materials, so that their use in building construction can give a valuable contribution to sustainability. This paper presents a natural multi-sheet wall package (named straw wall, SW) consisting of straw bale layer and innovative natural plasters, giving a rational evaluation of its potential of use in the sustainable building construction. The new building component was investigated by analyzing its environmental impact through the Life Cycle Assessment (LCA) from “Cradle to Gate” and its energy performance using dynamic simulation of a building case study; the energy saving potential of SW was assessed in different climate conditions in Italy. The innovative package highlighted excellent energy performance with respect to the NZEB reference, as prescribed by the Italian regulation, for all climates. Considering only the production and construction phases, the Embodied Energy associated to the innovative wall system is about the half of the value related to a traditional wall package and the CO2 equivalent emissions differ by more than 40%(Pescara site).

In the last few decades, the attention of researchers has been focused on the characterization of aerogels in order to improve the thermal performance of transparent building envelopes. Granular aerogel is already spread in the market thanks to the easy manufacturing system, whereas the difficulty in producing monoliths without defects, cracks, and inhomogeneity limited the diffusion of monolithic aerogel systems. A new production process for the monolithic panels was developed at Union College (Schenectady, NY, USA), it is a rapid supercritical extraction technique which allows a reduction in production time (only a few hours) and results in less solvent waste. Panes with maximum dimensions of about 100 &times, 100 mm were fabricated and composed in a unique glazing system, with external dimensions 300 &times, 300 mm. The thermal characterization of the innovative monolithic aerogel glazing system (simple float glazing 4.7-mm-thick monolithic aerogel pane 15-mm-thick simple float glazing 4.7 mm thick), which was carried out by means of a Small Hot Box apparatus, showed a thermal transmittance value of about 1.1 W/(m2K). Data was used in dynamic simulations of a typical non-residential building. They showed that the new investigated solution allows a valuable reduction with respect to a low-e double glazing system in terms of heating energy demand (about 5&ndash, 7% for Helsinki, 8&ndash, 12% for Paris, and 10&ndash, 15% for Turin), for different window-to-wall ratios.

The paper deals with the potential of high energy-efficient windows with granular silica aerogel for energy saving in building refurbishment. Different glazing systems were investigated considering two kinds of granular silica aerogel and different glass layers. Thermal transmittance and optical properties of the samples were measured and used in building simulations. The aerogel impact on heat transfer is remarkable, allowing a thermal transmittance of 1.0-1.1 W/(m2.K) with granular aerogel in interspace only 15 mm in thickness. A 63% reduction in U-value was achieved when compared to the corresponding conventional windows, together with a significant reduction (30%) in light transmittance. When assembled with a low-e glass, the U-value reduction was lower (31%), but a moderate reduction in light transmittance (about 10%) was observed for larger granules. Energy simulations for a case study in different climate conditions (hot, moderate, and cold) showed a reduction in energy demand both for heating and cooling for silica aerogel glazing systems, when compared to the conventional ones. The new glazings are a suitable solution for building refurbishment, thanks to low U-values and total solar transmittance, also in warm climate conditions. © 2017 by the authors.

Aerogel was one of the most promising nano-materials for use in buildings and its thermal performance was widely discussed in the literature while an accurate study of acoustic properties was never provided. The aim of the paper is to investigate experimentally the influence of granules size on both thermal and acoustic properties of granular aerogels and aerogel-based solutions (a plaster and a translucent polycarbonate panel) for energy saving in buildings. Several kinds of aerogels were investigated, ranging from small granules (0.01–1.2 mm) to large granules (1–4 mm). For each kind of aerogel, the absorption coefficient (α) and Transmission Loss (TL) were measured at normal incidence in a traditional impedance tube, taking into account 5 thicknesses (15, 20, 25, 30 e 40 mm) and thermal conductivity (λ) was evaluated by the Heat Flux Meter, setting up an appropriate methodology because of the sample nature. The aerogel granules outperformed the conventional insulating materials: depending on the particle sizes, λ varies in 19–23 × 10^(-3) W/(mK) range at 10 °C. The smallest granules (highest density) had the best performance, both in terms of thermal and acoustic insulation: α-values and TL better than the ones of rock wool were achieved (α = 0.95 and TL = 15 dB at about 1700 Hz). The good acoustic behaviour was confirmed also considering the two aerogel-based solutions for buildings: the peak of the absorption coefficient of the aerogel-based plaster was 0.29 at about 1050 Hz, compared to a value of about 0.1 of conventional plasters; simultaneously, λ diminished from 0.7 W/mK to 0.05 W/mK.

In the present paper CFD tool was used for thermal comfort evaluation in natural convection and in transient conditions in a room by setting only the external weather conditions as input parameters. A survey in a classroom at the Department of Engineering, University of Perugia, was carried out and data required for the thermal comfort evaluation and CFD simulation model set up was acquired. The simulation model was validated with experimental data and it was used for the thermal and velocity profiles simulation and for the thermal comfort indexes calculation, according to UNI 7730.

Coffee is one of the most frequently consumed drinks in the world. Coffee chaff, being the dried skin of the coffee bean, the husk, which comes off during the roasting process, is the only by product produced during the coffee beans roasting process. However, methods for the effective utilization of coffee chaff have not been developed. Reuse of coffee chaff, which is the primary residue from the coffee industry, is important for the environment and economy. Recently there have been some attempts to reuse the coffee chaff for energy production, biological materials, and as a nutrient source for solid-state fermentation. The purpose of this work is to propose coffee chaff as sound insulation and absorption material for the building industry. The experimental evaluation of the acoustic absorption properties of new samples made of coffee chaff was carried out. Different sample thicknesses were produced and tested by means of impedance tube, according to ISO 10534-2, showing a good behaviour at middle high frequencies. Porosity and flow resistance were also experimentally investigated. In order to highlight the environmental benefits, Life Cycle Assessment was carried out in terms of primary embodied energy and greenhouse gas emissions, considering a “cradle-to-gate” approach.

The present research reports the results of a questionnaire-based statistical study of some complex parameters derived from subjective answers by occupants regarding thermal comfort in their area of residence. There is not enough data regarding comfort in residential environment in Madagascar. This will help to define guidelines for constructing more comfortable buildings in Madagascar and other countries on the Indian Ocean. The experimental field study was carried out in 5 big hospitals, 50 small and big shopping centers, 67 traditional buildings, and 25 schools, which were distributed in 25 districts with different micro-climates of the urban communes in Northern of Madagascar. A total of 1092 people were investigated by means of 250 interviews and 842 analysed questionnaires during rainy and dry seasons. The physical measurements of air temperature and other parameters were performed simultaneously. Results showed that there were no very great differences between males and females thermal sensations, humidity sensations, and air movement sensations. The air temperature and relative humidity have a significant impact on the thermal preference in the studied place. With air temperature between 22.9 and 27.2 °C, relative humidity from 45.2 to 70.5%, associated with air speed varying from 0.15 to 0.45 m/s, at least 80% of voters found their environment comfortable.

The kinetic behaviour of olive tree pruning (PR), two- (2PH) and three-phase (3PH) olive pomace and their blends was investigated under combustion condition using thermogravimetric analysis. PR was blended with 2PH and 3PH at different ratios (25:75, 50:50 and 75:25) and tested in the temperature range from ambient to 1000 °C in order to evaluate the co-combustion behaviour. Results showed that the thermal degradation of all samples can be divided into three regions (drying, devolatilisation, char oxidation) with different combustion properties, depending on the percentage of PR. Significant interaction was detected between the fuels, and reactivity of 2PH and 3PH was improved upon blending with PR. The iso-conversional methods, Ozawa-Flynn-Wall and Vyazovkin, were employed for the kinetic analysis of the oxidation process. The results revealed that the activation energy of PR was higher than the one of 2PH and 3PH, and the minimum value was obtained for25PR752PH sample.

The evaluation of the thermal performance building components requires a high level of accuracy. Windows, doors and thermal bridges are not homogeneous, and their thermal transmittance can be evaluated by means of Hot-Box, used for full-scale elements. For homogeneous materials and one-dimensional heat flux, the thermal conductivity can be easily measured through other experimental apparatuses, such as the guarded hot plate and the heat flow meters. This study presents a new experimental apparatus named Small Hot-Box, built at the University of Perugia. No European standards are available for this innovative facility, but it takes into account some prescriptions of EN ISO 8990 and EN ISO 12567; it was built for the evaluation of the thermal properties of small specimens. The apparatus was designed, built, and calibrated by means of preliminary measurements. It is composed of a hot and a cold side, and the external walls are made of thick insulation. The thermal conductivity can be calculated by two different methodologies: the Hot-Box and the thermal flux meter method. Preliminary calibrations were carried out and different materials with known thermal transmittance were tested. The aim is the development of a new experimental apparatus; guidance documents could be defined for the measurements methodology requirements.

This work presents the study of tuff as an alternative material for CO 2 capturing and removal by pressure swing adsorption techniques. Tuff represents an economic and environmentally sustainable alternative to commonly-used synthetic zeolites. The proposed methodology includes a laboratory characterization of the CO 2 adsorption process under different operative conditions and experimental layouts. Measured data are also used to setup computational fluid dynamics simulations of the fixed-bed adsorption column. Results can be used to define optimal design parameters needed to implement and to improve different applications for biogas upgrading (CO 2 /CH 4 ratio adjustment) or carbon capture and storage.

The insulation of the building envelope contributes to the reduction of annual energy consumptions. The development of new materials, such as fibre reinforced insulating coatings, could be useful in order to obtain an effective solution for the improvement of energy performance and for reinforcement of the walls.\ud \ud The evaluation of the thermal and mechanical characteristics of building coatings with good thermal insulation properties and mechanical resistance is the aim of the present paper. A new experimental apparatus, Small Hot-Box, built at the University of Perugia, was used for the evaluation of the thermal conductivity of four different coatings (with and without a reinforced structure). No European standards are available for this innovative facility, but it takes into account some prescriptions of EN ISO 8990. The apparatus was calibrated with materials of known thermal conductivity. The thermal conductivity can be calculated with both the thermal flux meter and the Hot Box method. Good values of the thermal conductivity, in the range of 0.09–0.11 W/mK were found for all the samples, except for one (0.21–0.24 W/mK).\ud \ud Mechanical tests were also carried out in laboratory on all the samples and results were used to evaluate the shear modulus and strength of the wall panels.

This study focuses on the operating performance of a biomass boiler (100 kW) coupled with an absorption chiller machine at the service of a commercial building in central Italy. A detailed life cycle environmental assessment (LCA) was performed by comparing the biomass-fuelled system to conventional system, using the SimaPro software. To assess the environmental impact, experimental data, such as energy consumptions and emission factors of the biomass boiler, were used as input data. Biomass-fuelled system was found to have the lowest impact in cumulative energy demand (CED), global warming potential (GWP), and ReCiPe single score method.

A new 13-value thermal comfort scale is adopted in the present study, in order to evaluate the thermal comfort sensation within non-residential buildings with the adaptive approach. 18 classrooms located both in Pavia and Perugia, the Fraschini Theatre, and one auditorium located in Pavia were investigated from October 2014 to October 2015 collecting about 1600 questionnaires. All the information reported in the questionnaires was correlated by defining several indexes and a comparative analysis was carried out between the two comfort scales (13-value and 7-value scale). Results showed that using the new 13-value scale the percentage of people who declared a thermal sensation equal to 0 greatly decreased: from 66% to 41% for the classrooms and from 47% to 36% for the theatre-auditorium. The percentage of occupants who considered the environments not thermally comfortable, although they declared a thermal sensation equal to 0, also decreased, from a mean value of 10.4% to 2.7% for the classrooms and from 6.0% to 2.6% for the theatre-auditorium. Considering the 7-value scale, although a thermal sensation equal to 0 was declared, a higher percentage of people who would feel a little bit cooler or a little bit warmer was found. Instead using the 13-value scale, this percentage significantly decreased, because people declared a thermal sensation equal to ±0.5 (more than 50% of cases) instead of 0. In agreement with these results, the new scale seems to be more accurate than the traditional one, allowing a better correlation among all the data reported in the questionnaires.

The design, implementation, and setup of an innovative layout for geothermal heating and cooling systems are presented. An underground heat-storage tank, used as a thermal flywheel, decouples the utility side of the system (i.e., the heat pump) from the geothermal side (i.e., the boreholes). The innovative layout allows for a more efficient exploitation of the ground energy reservoir and a sensible reduction of investment costs.A pilot system has been realized for a commercial building near the city of Perugia, Italy. The design of the heat-storage tank, the heat exchangers, the monitoring system, and the operation modes were carefully studied. The heating performance monitoring shows that the innovative approach allows for a significant reduction of the ground heat exchangers, hence requiring for fewer and/or shorter boreholes (up to 75%) while still supplying the total energy need. The peak-power demand is covered taking advantage of the high thermal capacity of the water inside the tank, while ...

In Italy, the accumulation of driftwood along the shore is a significant issue, especially for the coastal municipalities of the Central and Northern regions. The purpose of this study was to evaluate the distribution and availability of the coastal driftwood in Italy and its impacts, as well as analyzing its chemical–physical properties to evaluate possible employment in combustion applications. On the basis of a data gathering campaign for the period 2010–2014, about 60,000 tons of driftwood are reported to accumulate along the Italian shores every year. The two regions hardest-hit were Liguria and Veneto, with about 15,000 tons and 12,000 tons, respectively. Three sites were selected for driftwood sampling. The main issue deriving from chemical characterization was the high chlorine content (up to 2% on dry basis) and metal oxides in the ashes. Driftwood samples were then subjected to a natural washing cycle for 1 month; results revealed a significant drop in chlorine and metal oxides contents (up to 80%) and a low decrease of the lower heating value (about 20%). Furthermore, the percolated water was analyzed in terms of chemical oxygen demand (COD), showing values (up to 1100 mg O2/L) above the Italian limits for discharges into surface waters.