Cool, translucent natural envelope. Thermal-optics characteristics experimental assessment and thermal-energy and day lighting analysis

Innovative construction elements are increasingly studied to improve the energy performance of new and existing buildings, to satisfy global regulations and societal needs. In this view, optimizing buildings energy efficiency and sustainability are crucial aspects, given their high energy saving potential with respect to the other sectors characterizing human activities. Natural materials are often preferred to artificial materials, thanks to their more sustainable production and to the reduced content of harmful substances. In particular, light, thin marbles have been recently analyzed as building envelope elements. Their cooling potential demonstrated how such envelopes have the threefold advantages of reducing solar heat gains into the building, accumulating and releasing less heat, reducing the Urban Heat Island (UHI) effect and consequently mitigating global warming. However, an important feature that has not yet been analyzed in literature and that is considered in this research is light passage throughout the translucent envelope, permitting an additional energy saving due to the contribution to artificial lighting. In this work, this feature of the translucent envelope is considered, by experimentally measuring thin, white marble panels’ optic characteristics and implementing them in a thermal-energy dynamic simulation, to demonstrate the additional advantage of natural daylight to the overall building energy balance

Experimental and Numerical Study on Thermal Performance of New Cool Clay Tiles in Residential Buildings in Europe

Abstract Energy demand imputable to buildings corresponds to around 40% of the total in most of the developed countries, showing the great potential in this field to propose and implement effective strategies for energy saving and environmental sustainability. Additionally, urban areas are the most impacted zones by anthropogenic sources and they are often affected by local climate phenomena such as urban heat islands. In this view, several measures to mitigate this effects and to save energy in constructions are dealt with the implementation of cool materials for roofs and urban paving. Since the majority of cities in Europe is characterized by traditional architectures in residential buildings, the implementation of white cool coatings is not feasible and new solutions are being proposed. In particular, starting from previous works of the authors about the development and continuous monitoring of cool clay tiles, this paper deals with the thermal analysis of low-visual-impact cool tiles in single family residential buildings with varying climate conditions (i.e. latitude) in Europe, from hot subtropical semi-arid climate (Tripoli) to oceanic climate (Munich). A calibrated and validated simulation model by mean of experimental in-lab and in-field measurements, has been used for studying the thermal effect of the proposed clay tiles. The analysis shows how the clay tile has a promising potential to decrease the indoor overheating in all the climate conditions, with relatively low penalties in winter even in the coldest areas

14th CIRIAF National Congress – Energy, Environment and Sustainable Development

CIRIAF (Inter-University Research Center on Pollution and Environment “Mauro Felli” is a research center, based at the University of Perugia, which promotes interdisciplinary research activities in the fields of environmental pollution and its health and socio-economic effects, sustainable development, renewable and alternative energy, energy planning, and sustainable mobility. One hundred professors from fourteen different Italian universities are involved in the activities of the center. The CIRIAF National Congress (e.g., the fourteenth one in 2014), has become, over time, an important event for researchers and experts (engineers, physicists, chemists, architects, doctors, and economists). These individuals are not simply academics; they also hail from ministries, environmental agencies, and local authorities. The annual meeting in Perugia is an opportunity to discuss the issues related to energy, environment and sustainable development. After some editions were devoted to panel discussions and workshops, the 14th Congress, which took place in Perugia from 4-5 April 2014, returned to the formula of parallel technical sessions. The Congress was quite successful. Seventy-nine papers were presented during the Congress; these were divided into the following eight Sessions, in line with the congress tradition. The session topics are of great contemporary interest: Built Environment Quality and Indoor Pollution Energy and Environmental Certification of Buildings Artworks Preservation and Museum Plants Renewable and Alternative Energy Sources and Systems Pollution from Physical Agents (noise, vibrations, electromagnetic fields) Air and Water Pollution Sustainable Mobility Energy Planning and Environmental Impact As usual, the ceremony of the “Mauro Felli” award took place during the Congress. The award, established to honor the memory of the founder and first Director of CIRIAF, is intended for young graduates, Ph.D. students or researchers who have carried out research activities in the fields concerning pollution originating from physical agents, the effects of environmental pollution on humans or related issues. Thanks to an agreement with the international publishing house MDPI, I am happy to introduce to you a special issue of SUSTAINABILITY, which contains the best papers presented at the Congress. The Special Issue will include the best papers presented at the Congress. These were selected by the Scientific Committee with the help of the various Chairmen of the Sessions. The papers cover all the various aspects of sustainability, from an interdisciplinary point of view, with a strong emphasis on the link between energy production, use and conservation, and environmental impact

On the Evaluation of Solar Greenhouse Efficiency in Building Simulation during the Heating Period

a flat equipped with a sunspace, recently built thanks to public contributions provided by the Umbria Region in Italy to widespread bio-climatic architecture, was used as case-study. Simulations were carried out for the examined flat, both with a steady-state tool and with a dynamic on

Smart cool mortar for passive cooling of historical and existing buildings: experimental analysis and dynamic simulation

In order to mitigate Urban Heat Island Effect and global warming, both governments and scientific community are working to reduce energy consumptions. In particular, the construction sector has a high potential in reducing energy demand, by means of both active and passive solutions. The European building stock is mainly composed by existing buildings as well as historical ones, which happens to be the less energy efficient ones. Moreover, retrofit operations are more complex on historical buildings, due to strict regulations for the preservation of such historical and cultural heritage. Considering this challenge, in this work we described and in lab analyzed possible passive solutions specifically designed for historical and existing buildings. In particular, we developed innovative cool colored mortars and tested them in lab, as well as investigated cool colored mortars, cool clay tiles and cool natural gravels performance when applied as envelope and roof elements, by means of dynamic simulation

Cool marble building envelopes. The effect of aging on energy performance and aesthetics

Marble envelopes represent a relatively common architectural solution used in variety of historic, modern and contemporary building facades. White marble envelopes have been shown to reduce solar heat gains, while improving indoor thermal comfort and energy efficiency in summer time. While marble is useful in this context, the urban atmosphere accelerates the degradation of marble elements. This leads to changes in optical characteristics, hence the aesthetics, and affects the energy efficiency benefits offered by white marble facades. These issues are investigated in order to predict the impact of degradation on energy performance and to the aesthetic value, such as change of color and luminosity. In this study, surface degradation of white marble is analyzed by means of accelerated weathering in the laboratory while examining changes to the optical characteristics of the materials. A dynamic simulation is carried out to assess the energy performance of a building as a case study

On a Cool Coating for Roof Clay Tiles: Development of the Prototype and Thermal-energy Assessment

AbstractClay tiles are the most common roof covering in Italian buildings, in particular in traditional residential buildings. Given the important role of the roof characteristics for building energy efficiency and indoor thermal comfort conditions, innovative solutions for improving the thermal-energy performance of such diffused roof element has become a key research issue. In this view, cool roof applications represent an effective solution to this aim. The present work deals with the analysis of innovative coatings for traditional clay tiles, aimed at increasing their "cooling" potential. Several pigments with the sodium silicate as binder are tested in terms of reflectance and emittance, which mainly determine the cool roof performance. Additionally, the year-round performance of the proposed tile is evaluated when applied to a single family residential building located in central Italy. The developed cool roof solution is characterized by the same visual appearance of traditional "natural brick" color tiles, while the solar reflectance is higher than natural terracotta tile by 13%. Therefore its thermal performance is optimized in order to reduce the roof overheating and the consequent energy requirement for cooling. Results of dynamic simulation of the case study building show how the proposed tile is able to decrease the number of hours when the indoor operative temperature of the attic is higher than 26°C by 18%, while the same effect in lowering the indoor temperature below 20°C in winter is less than 1%. Therefore, the proposed solution could be considered as an interesting strategy for new buildings or for traditional roof retrofitting, without producing any significant architectural impact, even in traditional or historic buildings, where more invasive solutions are too difficult to be implemented

New experimental technique to investigate the thermal behavior of PCM/doped concrete for enhancing thermal/energy storage capability of building envelope

Abstract In recent years, the scientific community has profusely investigated the chance of implementing advanced Thermal Energy Storage (TES) systems within building envelope components. In particular, several contributions have focused on the use of Phase Change Materials as passive TES strategies, to increment the thermal buffer potentiality of the building envelope. In this context, this work is focused on the development of a new experimental methodology for testing PCM-doped concrete composites in thermal-energy dynamic conditions. Such method, coupling controlled environmental forcing and transient plane source analysis, can be considered as an effective procedure for testing composite materials with adaptive thermal performance

Lignocellulosic Biomass Feeding in Biogas Pathway: State of the Art and Plant Layouts☆

Abstract The traditional pathway for biogas production consists in the anaerobic digestion of starchy and sugar biomass mainly from dedicated energy crops, needing agricultural land and heavy irrigation. A retrofitting of the existing biogas plants is proposed in order to reduce competition with food crops and to increase the sustainability of the whole chain in terms of land and water consumption; moreover the use of the lignocellulosic biomass is evaluated. The biomass after physical, chemical or biological pretreatment can be digested in a biogas plant to reduce the current diet without affecting the biogas production. The present study analyzes the state of the art in the lignocellulosic biomass feeding into biogas plants and describes a preliminary techno-economical study of the pathway and the layout to be adopted, including the efficiencies and energy yields of the involved processes