Authors:Oliveira C; Antonio F, Burani G, et al. Pages: 225 - 232 Abstract: AbstractThe objective of this study is to validate a zero-energy solar house (ZESH) as a sustainable development tool, based in accounting greenhouse gases (GHG) emissions mitigation. The method considers a multicriterial assessment for electricity conservation, power generation and GHG reduction. The potential and limitations of photovoltaic systems (PVSs) and the electricity consumption of the residential sector are studied. The guidelines and strategies of a ZESH are defined, focusing on the use of the sun in architecture, solar heating and PVSs through a qualitative analysis. These studies are carried out through a zero-energy house model (considering the annual consumption of a residence connected to the grid) that incorporates the guidelines and strategies of a solar house. The bioclimatic strategies and solar systems are analysed considering its application in São Paulo. The evaluation of passive strategies for thermal conditioning demonstrates a potential to increase by 70% the hours of comfort in the year. Using more efficient technologies for artificial lighting shows an energy conservation potential of around 12.5%, within the defined parameters and considering the average residential consumption. The use of a solar system to heat water has the potential to save up to 16.3% of energy compared to a business-as-usual scenario (traditional house). The electricity generation by PVSs combined with the adoption of energy efficiency measures demonstrates a potential to achieve, at least, zero net annual energy balance relative to the business-as-usual residential consumption of the grid. Thus, a potential to avoid up to 1.66 t CO2 per year for each housing unit is estimated. PubDate: 2017-07-05 DOI: 10.1093/ijlct/ctx004 Issue No:Vol. 12, No. 3 (2017)
Authors:Varga S; Soares J, Lima R, et al. Pages: 233 - 243 Abstract: AbstractComputational fluid dynamic tools have been widely used for the design and improvement of ejectors for cooling and other engineering applications over the last two decades. Most published works are based on the solution of the compressible RANS equations using commercially available codes. These codes provide a number of different turbulence models; however, very little information is available on which of these models are the most adequate to simulate ejector flow. Thus, the primary objective of this work is to assist researchers in the selection of a suitable turbulence model for the assessment of ejector cooling systems. Six turbulence models (standard k–ε, RNG k–ε, Realisable k–ε, standard k–ω, SST k–ω and Transition SST) are evaluated by comparing global performance indicators (coefficient of performance (COP) and critical back pressure) to experimental data obtained under a relatively wide range of operating conditions. Results clearly indicate that the Transition SST model predicts more accurately both the COP and the critical back pressure, with an average relative error of 4 and 1.4%, respectively, while the standard k–ω performs the poorest. By changing the model constants, from default to previously published values, in the standard k–ε model significantly improves COP predictions, only when the ejector operates in double-choking mode. PubDate: 2017-06-15 DOI: 10.1093/ijlct/ctx007 Issue No:Vol. 12, No. 3 (2017)
Authors:Hegazy I; Seddik W, Ibrahim H. Pages: 244 - 255 Abstract: AbstractOver the last 20 years, ‘green buildings’ have grown to become one of the most significant and progressive trends in the building industry. Sustainability is an extremely important direction, which has been given great attention and progress in recent years, especially in engineering and architecture. The paper motivates green building designers to ultimately transform their projects and innovate new techniques while demonstrating that built and natural ecosystems can integrate with each other using current technology. The research illustrates the sustainable design elements according to ‘The Living Building Challenge’. In this context, a building should be ‘Living’ when it achieves some imperatives: it has to generate its own energy on site using renewable sources, capture and treat its own water, be constructed of non-toxic and sustainable sourced materials, use only previously developed sites and be beautiful and inspiring to its inhabitants. Looking at these multiple processes encouraged moving beyond the concept of responsive architecture so that a ‘Living’ building can interact and adapt to external stimuli, it has to also inspire and educate the people who deal with it. The Bibliotheca of Alexandria is reviewed as a case study according to Living building qualifications in its existing condition and also investigate the possible scores and their feasibility in the case of a redevelopment of the project. PubDate: 2017-03-23 DOI: 10.1093/ijlct/ctx003 Issue No:Vol. 12, No. 3 (2017)
Authors:Zhang L; Zhang T, Pei G, et al. Pages: 256 - 262 Abstract: AbstractWickless loop thermosyphon solar water heating (LT-SWH) systems, which working under the passive and active cycle modes, were designed and experimental setup, systems’ performance were comparative studied. The results showed that pump made the active cycle system overcharged, a small hydraulic head was observed most of time; because of that, there was a worse photothermal performance under the active cycle mode, no matter in the comparison of the instantaneous photothermal efficiency or the collector and system performance linear fitting; at the same time, there was also a worse isothermality of the solar evaporator under the active cycle mode. PubDate: 2017-02-27 DOI: 10.1093/ijlct/ctx001 Issue No:Vol. 12, No. 3 (2017)
Authors:Ghazali A; Salleh E, Haw L, et al. Pages: 263 - 271 Abstract: AbstractPhotovoltaic (PV) façade, an envelope of the building in an urban area, can potentially produce clean electricity to meet the energy demand of the buildings and also provides protection from weather. This paper focuses on the application of PV technology on vertical façade of the building which is considered as an element of building-integrated PV. The aim of this study is to assess the feasibility with regard to performance evaluation of PV vertical façade based on the built-up model of a high-rise building in Malaysia using system advisor model. The best four vertical façade orientations for PV application in climatic condition of Malaysia are east, west, southeast and southwest as these façades received the highest incident irradiance. Based on the typical high-rise office building in Malaysia, the energy generated through the vertical PV system is between 400 and 700 MWh, whereas the energy generated by the roof system is ~240 MWh annually. PubDate: 2017-02-23 DOI: 10.1093/ijlct/ctw025 Issue No:Vol. 12, No. 3 (2017)
Authors:Durakovic B; Torlak M. Pages: 272 - 280 Abstract: AbstractIn this article, temperature-responsive window system based on phase change materials is studied by using experimental and numerical methods. The problem is analyzed for the real case (natural environment) and lab environment. Impact of glazing cavity size on the temperature flattening period and its limitations are determined and mathematically described. The results show that the design is effective in reducing interior air temperature variation by increasing the cavity thickness up to 24 mm, which is limited by solid/liquid volume fraction for particular environment. PubDate: 2016-10-27 DOI: 10.1093/ijlct/ctw024 Issue No:Vol. 12, No. 3 (2016)
Authors:Serrano S; Rincón L, González B, et al. Pages: 281 - 288 Abstract: AbstractRammed earth is considered a very sustainable construction system due to its low embodied energy, long service life and high recyclability. However, authors found that there is a lack of experimental results at real scale regarding rammed earth thermal behaviour. For this reason, this paper is first focused on the characterization of two different types of earth in order to check the suitability of being used in rammed earth walls. After the characterization, two experimental cubicle-shape buildings were built in Barcelona and Puigverd de Lleida (Spain) in order to test the thermal behaviour of their walls in two different climatic conditions. Temperature profiles inside walls have been monitored using thermocouples and temperature profile of southern walls was analysed in free floating conditions during summer and winter periods of 2013. Results show that thermal amplitude from outside to inside temperatures are decreased by rammed earth walls, achieving constant temperatures in inner surface of southern walls. PubDate: 2016-10-21 DOI: 10.1093/ijlct/ctw022 Issue No:Vol. 12, No. 3 (2016)
Authors:D'Alessandro A; Fabiani C, Pisello A, et al. Pages: 289 - 309 Abstract: AbstractThe article reviews the recent research contributions and future promising perspectives regarding innovation in concrete technologies for low-carbon applications in buildings. To this aim, an original classification of recent trends is presented for reducing the carbon footprint of concrete constructions by identifying three main research lines. The first one is related to the enhancement of physical and mechanical properties of concrete, the second one is related to resource efficiency and raw materials’ saving and the third one concerns the role of smart concretes in building energy efficiency. Possible synergies between the three addressed main research lines are finally discussed. PubDate: 2016-10-14 DOI: 10.1093/ijlct/ctw013 Issue No:Vol. 12, No. 3 (2016)
Authors:Anestopoulou C; Efthymiou C, Kokkonis D, et al. Pages: 310 - 322 Abstract: AbstractCoatings used in the indoor or outdoor façade of buildings seriously affect the flow of heat through the opaque elements and determine its energy performance. Sixteen envelope coatings for building façades presenting advanced thermal and optical properties, like low thermal conductivity, high solar reflectance, high emissivity and increased thermal capacity have been developed and tested. The expected energy conservation has been assessed considering different scenarios regarding coating's thickness and position for thermostatically controlled and free floating insulated and non-insulated buildings, located in heating and cooling dominated climates. Based on the results of this study, it was found that in average the energy saving for the cooling loads is up to 48.4% for Athens and 76.2% for Warsaw, while for heating loads is up to 17.2% and 11.8% respectively. Moreover, a proportional decrease was observed in the cooling degree hours (up to 36.8% for Athens and 74.3% for Warsaw) and in the heating degree hours (up to 11.8% and 8.5% respectively). It is concluded that the use of advanced coatings may considerably decrease the heating and cooling energy in buildings and significantly improve indoor thermal comfort conditions. PubDate: 2016-09-23 DOI: 10.1093/ijlct/ctw023 Issue No:Vol. 12, No. 3 (2016)
Authors:Lin Z. Pages: 323 - 329 Abstract: AbstractThe first decade of research into stratum ventilation is reviewed in the current manuscript. The background which midwifed the concept of stratum ventilation is introduced. Stratum ventilation is found to provide thermal comfort in warm conditions. Possible reasons behind this are explored. Because air is directly delivered to the breathing zone, the indoor air quality under stratum ventilation is improved. Substantial energy saving can be achieved with stratum ventilation. Studies revealed that nine factors contribute to this saving. Some transient processes under stratum ventilation were investigated and useful results attained. Design guidelines are suggested. PubDate: 2016-07-08 DOI: 10.1093/ijlct/ctw020 Issue No:Vol. 12, No. 3 (2016)
Authors:Hu S; Shiue A, Chang S, et al. Pages: 330 - 334 Abstract: AbstractCarbon dioxide in an indoor environment is one of the air pollutants monitored by the Indoor Air Quality Ordinance of Taiwan. It is necessary for people and the air-conditioning industry to take appropriate measures to minimize the emission and prevent creating an unacceptable indoor air quality (IAQ). This study presents the performance of sorption-type air filters to help people and the air-conditioning industry to understand and apply the best practical control to prevent CO2 emissions from causing IAQ problems. The adsorption of CO2 with a sorption-type filter with activated carbon before and after impregnating treatment has been investigated. It has been found that impregnation treatment with MgO and CaO can promote the adsorption of CO2 on a sorption-type filter, with MgO being the better of the two. PubDate: 2016-07-05 DOI: 10.1093/ijlct/ctw014 Issue No:Vol. 12, No. 3 (2016)
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