Life cycle assessment of energy efficient buildings

Abstract Life Cycle Analysis applications in the construction sector are growing due to the increased importance of embodied components in low energy buildings. In this study, standard building reference scenarios were compared with highly efficient building typologies, classified as low-energy or nearly Zero Energy Buildings. Energy consumptions were simulated starting from validated models while uniform assumptions, such as materials to be included, stages to be considered and coefficients of impact to be applied, were made for the LCA. The results show how the enhanced energy efficiency in the examined buildings and the reduction of their operational non-renewable primary energy requirement correspondingly causes a decrease of their life cycle non-renewable energy requirement, Cumulative Energy Demand and Global Warming Potential. A high potential in the reduction of non-renewable operational primary energy and GWP was found (until a maximum of 89% for the energy and 88% for the emissions). However, due to the shifting of impacts to the embodied components, the achievable life cycle reduction of non-renewable primary energy and emissions is lower (respectively 60% and 63% for the best performing retrofit). The benefit on life cycle CED is even lower due to the energy transition to renewables

A review of unconventional sustainable building insulation materials

AbstractBuilding insulation is commonly realized using materials obtained from petrochemicals (mainly polystyrene) or from natural sources processed with high energy consumptions (glass and rock wools). These materials cause significant detrimental effects on the environment mainly due to the production stage, i.e. use of non-renewable materials and fossil energy consumption, and to the disposal stage, i.e. problems in reusing or recycling the products at the end of their lives. The introduction of the concept of "sustainability" in building design process encouraged researches aimed at developing thermal and acoustic insulating materials using natural or recycled materials. Some of them, such as kenaf or wood fiber, are already commercialized but their diffusion could be further improved since their performance is similar to the synthetic ones. Others are currently under study and their development is only at an early stage. The goal of the paper is to report a state of the art of building insulation products made of natural or recycled materials that are not or scarcely commercialized. Comparative analyses were carried out considering in particular thermal characteristics in terms of thermal conductivity, specific heat and density. Data on the acoustic performance of the materials were also reported. Life Cycle Assessment data were finally collected, in order to put in evidence the environmental advantages of these materials. Particular attention was paid to researches focused to exploit local materials and even industrial byproducts, since these approaches respectively limit transportation and disposal impacts

Evaluating in situ thermal transmittance of green buildings masonries—A case study

Abstract The determination of the thermal properties of a building envelope is fundamental for the correct design of energy efficient constructions. Opaque walls can be easily modeled as parallel and homogeneous layers, being characterized by a monodimensional thermal flux which allows to evaluate the thermal transmittance with analytical models. These procedures are well established and they lead to reliable results; however, it is important to verify the actual performance with in situ thermal transmittance measurements. This analysis is more important when the wall performance is high, being closely linked to economic assessments. The paper presents the results of a measurement campaign of in situ thermal transmittance, performed in some buildings in the Umbria Region (Italy), designed implementing bio-architecture solutions. The analyzed walls were previously monitored with thermographic surveys in order to assess the correct application of the sensors. Results of the investigation show that in situ thermal transmittance measurements and theoretical calculated U -value are not in perfect agreement. The mismatch becomes important for monolithic structures such as walls made of thermal blocks without insulating layers

Noise Mapping Special Issue: The noise climate at the time of SARS-CoV-2 Virus/COVID-19 Disease

Introducion to the special issu

Experimental Performance Analyses of a Heat Recovery System for Mechanical Ventilation in Buildings

Abstract Nowadays the increasing trend to make buildings more and more energetically efficient leads to an improvement of the thermal performance of the elements such us walls, windows and doors, making the envelope a strong barrier between the indoor and outdoor environment, also for air infiltrations. If this circumstance results useful for energy consumption reduction, it constitutes a problem for indoor air quality and comfort. Mechanical ventilation systems are often provided, and, at the aim of abating the thermal (or cooling) loads linked to the inlet of air from the external environment, heat recovery systems became more and more popular; for high values of air mass flow treated, many national regulations make the installation of heat recovery systems compulsory. An experimental test bench was built at the Thermal Engineering Laboratory of the University of Perugia, aimed at evaluating the performance of air heat recovery devices. The first measurements were carried out on a commercial plate-type heat exchanger, made of polystyrene. This plastic material is characterized by a low value of thermal conductivity, but its easiness of workability allows to increase the heat exchange surface, overcoming also issues linked to the weight and the cost of the product. The flow-rates, the pressure drops, and all temperatures of interest for the heat exchanger were acquired. The energy efficiency index of the heat recovery system was assessed with several tests conducted with different boundary conditions of the indoor and outdoor ambient, as well as different air flow rates. Results were compared with data gathered from the manufacturer, highlighting the points of contact and the differences between the experimental outcomes and the company information sheet, providing further details that are commonly not available

Influence of insulating materials on green building rating system results

This paper analyzes the impact of a change in the thermal insulating material on both the energy and environmental performance of a building, evaluated through two different green building assessment methods: Leadership in Energy and Environmental Design (LEED) and Istituto per l'innovazione e Trasparenza degli Appalti e la Compatibilità Ambientale (ITACA). LEED is one of the most qualified rating systems at an international level; it assesses building sustainability thanks to a point-based system where credits are divided into six different categories. One of these is fully related to building materials. The ITACA procedure derives from the international evaluation system Sustainable Building Tool (SBTool), modified according to the Italian context. In the region of Umbria, ITACA certification is composed of 20 technical sheets, which are classified into five macro-areas. The analysis was developed on a residential building located in the central Italy. It was built taking into account the principles of sustainability as far as both structural and technical solutions are concerned. In order to evaluate the influence of thermal insulating material, different configurations of the envelope were considered, replacing the original material (glass wool) with a synthetic one (expanded polystyrene, EPS) and two natural materials (wood fiber and kenaf). The study aims to highlight how the materials characteristics can affect building energy and environmental performance and to point out the different approaches of the analyzed protocols

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

Evaluation of Net Energy Obtainable from Combustion of Stabilised Olive Mill By-Products

This work is aimed at calculating the energy content of the residues from olive oil production. Olive pulp, olive husk and sludge (a mixture of olive pulp and husk) have been analyzed separately. Olive Mill Effluents (OME) are normally a problem for olive mill farms, yet they may be used as feedstock for biomass-fuelled power plants. Nonetheless, OMEs are characterized by a relatively high humidity content and are produced only during the olive season. Thus, OME need a stabilization process to be employed as a solid biofuel throughout the year. The analyses conducted attempt an evaluation of the energy consumption of a three-stage stabilization process: drying, milling and pelletising. The net electrical energy available from OME is then calculated as a difference between gross energy available and energy consumed for stabilization. The gross available electrical energy was calculated based on direct energy conversion of the stabilized feedstock on a small scale direct combustion and Organic Rankine Cycle (ORC) turbine. Results show that OME are suitable for energy production. Approximately 4500 kJ/kg of net electrical energy may be obtained out of olive sludge or olive pulp, while olive husk shows a potential gross energy of 3400 kJ/kg