Procedia environmental sciences最新文献

The present paper firstly deals with the steel structurés contribution to existing building safety factor increase. In a second stage, the response of the structural masonry–steel system after rehabilitation of the whole building with additional steel roofs is analyzed. The building at hand was chosen as a representative sample of the architectural wealth of the plethora of the so-called neoclassical buildings available in the town of Veria. The analysis includes a description of the building's characteristics and pathologies, with an estimation of the structural performance under an optimization process when using steel structures for its enhancement. The last part of the paper concerns conclusions, recommendations and proposals for renovation, maintenance, strengthening and extension of historic buildings of this type.

This study examines the temperature distribution and the flow field in a naturally ventilated room with a localized floor heat source. The room has an orthogonal form with a low and a high opening placed in opposite walls. The temperature of outdoor air is cooler than the initial indoor air temperature forming buoyancy-driven natural ventilation (with U_wind≈0). The problem is explored with computational simulation using a CFD software. A model validation is presented with experimental and computational results of previous investigation^10,11 on natural ventilation including buoyancy forces. The 3D unsteady Reynolds Averaged Navier Stokes (RANS) equations are solved in conjunction with the energy equation and the turbulence RNG k-ɛmodel. The unsteady flow of natural ventilation with buoyancy forces is analyzed andthe vertical variation of temperature with respect to timeis investigated. A thermal stratification is formed which is justified by the respective indoor air movement. The upper buoyant layer is warmer than the bottom one, while the indoor air temperature of both layers increases with time. A thermal comfort exploration accompanies the outcoming results and provides useful information for similar problems. Finally, a number of conclusions are derived about the simulation process, the function of natural ventilation and the thermal comfort of the space in corresponding cases.

A corner Double Skin Façade curtain walling facing south and west orientation that has been applied in Athens Greece was examined during cooling season. The external skin of the double skin façade is made out of rotating sandblasted striped glass louvres on its external skin on both elevations. During the cooling season, measurements were done on both elevations with the intention to examine in detail the performance of the curtain walling. Measurements were done using thermocouples in particular areas of the construction for several days and different methods were followed to allow the determination of the airflow in the cavity. The external skin which is adjustable was examined in vertical and inclined position with the aim to identify when it is performing properly and how its performance can be optimized. Throughout the analysis, it was realised that the South elevation is functioning ideally thanks to a multi-layered shading that is achieved by the sandblasted striped glass louvres when they are positioned inclined. On the contrary, it can be identified that the west elevation is not performing sufficiently as the vector of the solar irradiance is differing in comparison to the midday where the irradiation is facing the south orientation from a significantly different position. As a result the multi-layered shading in the west elevation is not functioning properly and for this reason the measured temperatures on both the internal skin of the Double Skin Façade and the interior of the building prove that corrective measures are required with the aim to avoid overheating problems.

In the light of mounting concerns related to climate change, energy efficiency and conservation (EEC) presents a cost-effective strategy that can propel the Philippines’ energy-intensive tourist accommodations sector towards sustainability. This warrants the examination of barriers that prevent capture of EEC potentials and the identification of factors that will drive adoption at a socially- optimal rate.

Coron, Palawan's small and medium enterprise (SME) dominated hospitality sector was studied using post-only correlation design. Mann-Whitney U test was used to compare perceptions, practices, energy awareness, and willingness to participate in EEC between members of the Zero Carbon Resorts project; a voluntary program aiding tourism SMEs reduce energy consumption (Case Group), and non-members (Control Group). Pearson Chi-Squared test was employed to determine factor association with membership in the program, while Ordered Logistic Regression was used to determine participation drivers in EEC.

Research revealed vast uncaptured energy-savings potential compounded with the absence of EEC laws targeting this sector. The study found that: (1) provisions for amenities, facilities and support services for guests; (2) high dependence on the grid and the prevalent use of generators; (3) low market penetration of renewable energy (RE) and energy-efficient technology; and (4) lack of knowledgeable personnel within organizations contribute to high energy expense within this sector. Despite having very little difference in perceived energy savings, energy awareness and self-reported energy-saving practices vary widely. Policy and institutional changes are required to address: (1) perceived high cost of energy-efficient technology and knowledge gap, (2) put in place necessary regulations; and (3) incentivize EEC to increase its adoption.

The current paperⁱ aims at developing a set of design guidelines that promotes the concept of socially sustainable neighbourhoods in Saudi Arabia. Nowadays, several rating systems and urban design codes around the world set guidelines for urban design development and particularly in neighbourhood design. The research problem is; these rating systems cannot be applied in the context of Saudi Arabia without considering its local social and cultural aspects. The paper resulted as a reaction to the abbreviation of socio-cultural aspects in neighbourhood design approaches. The paper presents a set of design guidelines adjusted to fit the context of Jeddah City.

Towards the EPBD recast 2010/31/EU and the nearly zero energy building (nZEB), this review addresses the whole life cycle energy analysis of residential buildings. Life Cycle Energy Analysis (LCEA) of 90 case studies of residential buildings is evaluated with a specific focus on the normalization procedure that follows the principles of Product Category Rule (PCR) 2014:02 for buildings. The normalization procedure provided a minimization of the sample by considering issues of comparability, the omissions in the boundaries of the system, the LCI method and the updating on the energy efficiency definition of the building. Results indicate that the use of different LCI methods leads to an important fluctuation in the absolute values of embodied energy as the embodied energy of annZEB calculated with process analysis is lower than every case study calculated with hybrid input-output analysis without including nZEBs. The share of embodied energy in low energy buildings could reach up to 57% -or even up to 83% when renewable energy sources are used for electricity production- and in nZEBs up to 100% even though a significant reduction in the total life cycle energy is identified. The increase in embodied energy and a difference of at least 17% in the share of embodied energy between low energy and nearly zero energy buildings indicate that maybe LCEA should be considered in energy efficiency regulations along with further standardization.

During the last 20 years, the need to specific measurable systems to assess the sustainability level of green building had been discussed. Many countries have adopted the LEED rating system as an assessment tool of sustainability. The research aim is to examine LEED-NC to determine whether it is applicable in the Middle East Countries. An analytical study of 25 projects in the Middle East is carried with different attributes using an international benchmark, to find out how it works. This indicates the main factors that should be taken in consideration in the assessment process for LEED NC in the MEC.

The aim of this study is to analyse the thermal behaviour of walls corresponding to perforated clay brick masonry layers. The complexity of this work relies on the effect of all heat transfer mechanisms simultaneously; therefore, apart from conduction through the solid material, the propagation of heat depends on convection and radiation mechanisms in the region of the air cavities (pattern of small holes). Evidently, the geometry of perforated bricks and mortar joints of the brickwork, as well as the thermophysical properties of building materials, can modify significantly the evolution of the heat wave under specific boundary conditions at both external/internal sides of the examined layer (ambience). Furthermore, the dynamics of the actual heat flow are affected by the values of thermal-emissivity at the exposed surfaces of the brick holes. In this study, several of these issues are analysed in order to expose their influence on the thermal response of perforated clay brick masonry walls. The transient thermal analysis was carried out by employing the finite element method and by adopting a well-known CFD program focused on heat transfer processes. Secondly, the investigation has been extended to determine the corresponding thermophysical properties of an analogous solid layer (same thickness) that can produce an equivalent heat wave excitation at its interior surface. The resulting values can be useful to promote the building design and diminish the uncertainties regarding the heat flows through building envelopes; besides, assessing precisely the thermal behaviour of building configurations is essential, since the calculation of energy requirements through buildings has become of increasing importance lately.

When energy upgrade measures are suggested for existing buildings, usually the market availability of the selected technology, in relation to costs are taken into consideration; the latter are usually expressed as the investment payback period, in relation to the savings from energy bills that are achieved. Yet, the embodied energy payback period is not taken into consideration, in relation to the respective energy savings; this payback period is considered to be very crucial since it is an indicator of whether the specific energy saving measures should be followed, so that their embodied energy is paid back within the rest of the building's life span, showing finally whether the building should be energy upgraded or not, from a holistic energy point of view.

In this work a “typical” dwelling building apartment is considered in all four climatic zones of Greece. Materials and techniques are examined on this building, so as to achieve the minimum requirements of the existing legislative energy upgrade, as well as transforming it into a nearly zero energy building (nZEB). The parameters used are according to the Greek legislationwith regards to occupancy and building use. Materials and techniques investigated are chosen with market availability criteria. A parametric analysis of materials and techniques with different embodied energies is considered and their payback periods are examined for all case studies. Conclusions are drawn on which materials and techniques should be preferred and which should be avoided for the energy upgrade of existing buildings in the climatic zones of Greece, in order to achieve the minimum legislative energy consumption requirements or an nZEB, based on their energy payback period.