scholarly journals Numerical Assessment of Zebra-Stripes-Based Strategies in Buildings Energy Performance: A Case Study under Tropical Climate

Biomimetics ◽  
2022 ◽  
Vol 7 (1) ◽  
pp. 14
Author(s):  
Miguel Chen Austin ◽  
Kevin Araque ◽  
Paola Palacios ◽  
Katherine Rodríguez Maure ◽  
Dafni Mora

Urban growth has increased the risk of over-heating both in the microclimate and inside buildings, affecting thermal comfort and energy efficiency. That is why this research aims to evaluate the energy performance of buildings in terms of thermal comfort (operative temperature (OP) levels, satisfied hours of natural ventilation SHNV, thermal lag), and energy efficiency (roof heat gains and surface temperatures) in an urban area in Panama City, using superficial-heat-dissipation biomimetic strategies. Two case studies, a base case and a proposed case, were evaluated using the Designbuilder software through dynamic simulation. The proposed case is based on a combined biomimetic strategy; the reflective characteristics of the Saharan ant applied as a coating on the roofs through a segmented pattern such as the Zebra’s stripes (one section with coating, and another without). Results showed that the OP decreased from 8 to 10 °C for the entire urban zone throughout the year. A reduction of 3.13% corresponding to 8790 kWh per year was achieved for cooling energy consumption. A difference of 5 °C in external surface temperature was obtained, having a lower temperature in which the biomimetic strategy was applied. Besides, it was evidenced that a contrasted-reflectivity-stripes pitched roof performed better than a fully reflective roof. Thus, the functionality of Zebra stripes, together with the reflective characteristics of the Saharan ant, provide better performance for buildings’ thermal regulation and energy needs for cooling.

Energies ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3311
Author(s):  
Víctor Pérez-Andreu ◽  
Carolina Aparicio-Fernández ◽  
José-Luis Vivancos ◽  
Javier Cárcel-Carrasco

The number of buildings renovated following the introduction of European energy-efficiency policy represents a small number of buildings in Spain. So, the main Spanish building stock needs an urgent energy renovation. Using passive strategies is essential, and thermal characterization and predictive tests of the energy-efficiency improvements achieving acceptable levels of comfort for their users are urgently necessary. This study analyzes the energy performance and thermal comfort of the users in a typical Mediterranean dwelling house. A transient simulation has been used to acquire the scope of Spanish standards for its energy rehabilitation, taking into account standard comfort conditions. The work is based on thermal monitoring of the building and a numerical validated model developed in TRNSYS. Energy demands for different models have been calculated considering different passive constructive measures combined with real wind site conditions and the behavior of users related to natural ventilation. This methodology has given us the necessary information to decide the best solution in relation to energy demand and facility of implementation. The thermal comfort for different models is not directly related to energy demand and has allowed checking when and where the measures need to be done.


Heritage ◽  
2018 ◽  
Vol 1 (1) ◽  
pp. 57-87 ◽  
Author(s):  
Ahmed Khalil ◽  
Naglaa Hammouda ◽  
Khaled El-Deeb

Sustainable design is believed to stand on the opposite side of heritage conservation. This view is supported by the fact that sustainable design requires invasive measures to implement new technologies and treatments that challenge the principle of minimum intervention in heritage conservation. Another point of view sees heritage conservation as an already act of sustainable development that protects and preserves social and cultural resources such as heritage buildings and their intangible values. On the other hand, research and practice have proven that heritage buildings can be the subjects of sustainable design projects that achieve outstanding measures of sustainability and energy efficiency while not compromising the authenticity of the heritage value of the building. This sustainable conservation reaches its peak in adaptive-reuse projects of heritage buildings as reusing the building guarantees its ongoing maintenance and promotes its social, cultural and economic values to society, while giving it the ability to withstand modern users’ comfort and energy efficiency standards. This research presents a case study of the adaptive-reuse project of Villa Antoniadis in Alexandria; a heritage building built in the mid-nineteenth century and in the process of a major adaptive-reuse project. The history and significance of the building will be studied as well as the conservation values of the current project, then some proposals for interventions that could achieve more energy efficiency for the project while conserving the building are discussed. The research included a simulation of the building, using building energy modelling software for the current adaptive-reuse project as a base case, and the hypothetical application of different proposed sustainable interventions such as thermal insulation, double glazing, shading, lighting control, natural ventilation, and photovoltaic energy generation, where the energy savings potentials for each proposed intervention were studied. The simulation proved a possible reduction of 36.5% in the cooling, heating and lighting energy consumption as well as generated 74.7% of the energy required for cooling, heating and lighting from renewable energy sources.


2021 ◽  
Vol 13 (0) ◽  
pp. 1-6
Author(s):  
Rasa Džiugaitė-Tumėnienė ◽  
Domas Madeikis

The high share of global energy costs to create an indoor climate has been of increasing interest to the global community for several decades and is increasingly the focus of policy. This paper analyses the energy performance gap between actual energy consumption and energy demand obtained during the dynamic energy simulation and building certification. To identify the energy performance gap, an existing office of energy efficiency class B was selected as a case study. The simulation program IDA Indoor Climate and Energy was used to create a dynamic energy model, based on the designed documentation and the actual indoor climate parameters recorded by the building management system. The results of the case study showed that the accuracy and reliability of the results presented by the dynamic energy model of the building directly depend on the assumptions. The correct values of the internal heat gains, indoor climate parameters, human behavior, air quality levels at different times of the day and season, HVAC system operation parameters and operation modes, specific fan powers of ventilation systems, the seasonal energy efficiency of cooling equipment and characteristics of sun protection measures have to be selected.


Author(s):  
Mauro Cepeda ◽  
Santiago Morales F. ◽  
Viviana Cabrera

When high thermal comfort and energy efficiency are provided in an academic environment many beneficial effects on student’s comfort, performance, productivity, and health are shown. The research provides a parametric airflow evaluation of a skylight in a ground floor of new educational building assuming a variation of 4 stages with eight scenarios for the admissions office. By means of the bioclimatic analysis, Predicted Mean Vote (PMV) and Predicted Percentage of Dissatisfied (PPD) indices, the best internal airflow performance for the study area applying natural ventilation is achieved with the air flow optimization. A minimum area of 1.79 m has been established for extraction and movement of the internal flow, both with the natural extraction louvers system measuring 12 inches by 60 inches and the 18 inches by 60 inches, they work properly. However, the 18 inches by 60 inches system has better effectiveness as it has fewer louver units to be placed, is more homogeneous, avoids turbulence and provides better air extraction. In addition, by having fewer louver units distributed along the length of the skylight, it will allow the operation to be more controlled during the operation of the building. The use of 8 louvers of those proportions, with an individual effective area of 0.23 m and a total of 1.84 m was recommended in accordance with the results obtained.


2019 ◽  
Vol 111 ◽  
pp. 03037
Author(s):  
Merve Atmaca ◽  
Zerrin Yýlmaz

In Turkey, according to TUİK Sectoral Energy Consumption Statistics (2006), the hotel buildings with the highest share, constitute 35% of the total building energy consumption. Energy needs and consumption behaviours differ according to the typology of the building. Energy Performance of Buildings Directive (EPBD) has been adapted to the conditions of Turkey to increase energy and cost efficiency, to reduce the environmental and economic negative effects. The energy consumption and the global cost were investigated under different conditions in an existing hotel building. The paper is unique in its ability to deliver optimum solution through comparison by evaluating energy and cost efficiency at the same time considering sectoral, climatic, technological and economic national conditions when the literature research detailed in the present works about the problem is evaluated in detail. All findings have been compared simultaneously under different climate regions of seasonal and yearly working conditions of selected test hotel to obtain the energy and cost efficiency. Among the proposed improvement scenarios, the optimum scenario is determined in terms of cost and energy efficiency in S18 which has the highest energy efficiency. In this case, both insulation material type and thickness as well as glass type can be bent and through multiple measures can be achieved by 25.7% improvement for energy efficiency.


2020 ◽  
Vol 41 (3) ◽  
pp. 247-260
Author(s):  
Roy Candra Sigalingging ◽  
David Chow ◽  
Steve Sharples

In a hot and humid tropical climate, natural ventilation brings high levels of moisture into dwellings that, together with occupant activity, can result in very elevated internal relative humidity levels. Coupling these high relative humidities with high internal air temperatures creates occupant thermal discomfort, which is typically ameliorated in the tropics using energy-intensive air conditioning systems. This paper has investigated the potential benefits for thermal comfort and energy usage of applying the German Passivhaus standard to tropical dwellings. By creating a super insulated and air-tight envelope, the Passivhaus standard reduces fabric heat transfer, controls air infiltration and provides low-energy comfort. Applying this approach to a tropical terraced house might be effective but could, potentially, have an adverse impact on mechanical cooling demand. This study took an actual terraced property in Jakarta, Indonesia and thermally modelled its performance as insulation and airtightness levels were incrementally improved up to the Passivhaus standard. Field measurements in the dwelling of air temperature and relative humidity were used to validate the thermal model of the existing house. The validated model then tested the feasibility of meeting the Passivhaus energy standard for cooling in the modified tropical house. Simulation allowed the effects of air conditioning (AC) and dehumidifiers on thermal comfort and cooling loads to be investigated. The research develop the Passivhaus building model that had the floor insulation removed to let the ground floor act as a thermal sink and potentially provide radiant cooling. Analysis revealed that the building’s predicted air temperatures were affected in a beneficial way by having the Passivhaus without floor insulation. Practical application: Cooling in hot and humid tropical region is an energy-intensive approach. Design approaches that can bring comfort and save energy for the occupant are essential. The success of Passivhaus standard in mild climate might be transferable to bring comfort in tropical housing. Best practice can be developed by analysing the Passivhaus building performance in hot and humid tropical region.


2019 ◽  
Vol 158 ◽  
pp. 3319-3324 ◽  
Author(s):  
Vincent J.L. Gan ◽  
M. Deng ◽  
Y. Tan ◽  
W. Chen ◽  
Jack C.P. Cheng

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