scholarly journals Comparison of the thermal performance between conventional and cob building

2019 ◽  
Vol 111 ◽  
pp. 03003
Author(s):  
Kaoutar Zeghari ◽  
Hasna Louahlia ◽  
Malo Leguern ◽  
Mohamed Boutouil ◽  
Hamid Gualous ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Thermal Behaviour ◽  
Calculation Method ◽  
Building Materials ◽  
Residential Building ◽  
Local Heat ◽  
Energy Performance ◽  
Stationary Regime ◽  
Thermal Regulation ◽  
Climate Data

The appliance of sustainable development approach in building has urged construction industry to adopt proper measurements to protect environment and reduce residential building energy consumption and CO2 emissions. Thus, an increasing interest in alternative building materials has developed including the use of bio-based materials such as cob which is studied in this paper. In the previous work, many experimental and numerical studies have been carried out to characterize thermal behaviour of earth buildings, reduce its thermal conductivity and water content. In this paper, an experimental study is carried out to determine the thermal properties and energy performance of cob building. Cob samples within different soil and fiber contents are studied using an experimental set up instrumented with flux meters and micro-thermocouples in order to evaluate the local heat flux and thermal conductivity during stationary regime. The results are analysed and compared to deduce the performant mixes in terms of thermal behaviour while respecting the French thermal regulation. A static thermal simulation based on RT 2012 calculation method (the official French calculation method for the energy performance of new residential and commercial buildings according to France thermal regulation) is used to compare energy performance between conventional and cob building using the French climate data base .

scholarly journals Testing a Gypsum Composite Based on Raw Gypsum with a Direct Admixture of Paraffin and Polymer to Improve Thermal Properties

Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3241
Author(s):  
Krzysztof Powała ◽  
Andrzej Obraniak ◽  
Dariusz Heim
Keyword(s):  
Thermal Conductivity ◽  
Heat Capacity ◽  
Thermal Properties ◽  
Phase Change ◽  
Large Scale ◽  
Building Materials ◽  
Residential Buildings ◽  
Energy Performance ◽  
Polymer Content ◽  
Volumetric Heat Capacity

The implemented new legal regulations regarding thermal comfort, the energy performance of residential buildings, and proecological requirements require the design of new building materials, the use of which will improve the thermal efficiency of newly built and renovated buildings. Therefore, many companies producing building materials strive to improve the properties of their products by reducing the weight of the materials, increasing their mechanical properties, and improving their insulating properties. Currently, there are solutions in phase-change materials (PCM) production technology, such as microencapsulation, but its application on a large scale is extremely costly. This paper presents a solution to the abovementioned problem through the creation and testing of a composite, i.e., a new mixture of gypsum, paraffin, and polymer, which can be used in the production of plasterboard. The presented solution uses a material (PCM) which improves the thermal properties of the composite by taking advantage of the phase-change phenomenon. The study analyzes the influence of polymer content in the total mass of a composite in relation to its thermal conductivity, volumetric heat capacity, and diffusivity. Based on the results contained in this article, the best solution appears to be a mixture with 0.1% polymer content. It is definitely visible in the tests which use drying, hardening time, and paraffin absorption. It differs slightly from the best result in the thermal conductivity test, while it is comparable in terms of volumetric heat capacity and differs slightly from the best result in the thermal diffusivity test.

A Performance Comprehension of Various Numerical Estimators for Variance-Based Sensitivity Analysis in Building Energy Simulations

2019 ◽  
Author(s):  
Rasool Koosha ◽  
Fatemeh Shahsavari
Keyword(s):  
Sensitivity Analysis ◽  
Building Materials ◽  
Computational Cost ◽  
Residential Building ◽  
Building Energy ◽  
Energy Performance ◽  
Test Case ◽  
Sensitivity Index ◽  
Energy Simulations ◽  
High Level

Abstract In the building energy performance simulation, the uncertainty analysis (UA) couples to the sensitivity analysis (SA) to handle ever-existing uncertainties; induced by the sources of uncertainty including random occupants behavior and degradation of building materials over time. As a building simulation tool reaches to a high level of complexity, it becomes more challenging for the sensitivity analysis to deliver reliable outputs; thus the accuracy of the SA results substantially depends upon the number of sample sets or the type of analysis performed. This paper describes a variance-based SA tool integrated into a building Resistance-Capacitance (RC) thermal model. Then, for a hypothetical residential building test case, three distinct first-order sensitivity index simulators and three total sensitivity index simulators are implemented and compared in terms of the dependency of results on the sample size, i.e., the demand for the computational cost.

scholarly journals Convective and conductive thermal homogenization for non-saturated porous building materials: Application on the thermal conductivity tensor

2018 ◽  
Vol 22 (6 Part A) ◽  
pp. 2367-2378 ◽  
Author(s):  
Fares Bennai ◽  
Kamilia Abahri ◽  
Rafik Belarbi ◽  
Abdelkader Tahakourt
Keyword(s):  
Thermal Conductivity ◽  
Porous Materials ◽  
Building Materials ◽  
Complex Structure ◽  
Energy Performance ◽  
Elementary Cell ◽  
Conductivity Tensor ◽  
Transfer Model ◽  
Microscopic Scale ◽  
Thermal Conductivity Tensor

Porous materials possess a complex structure on a microscopic scale and present strong heterogeneities, which makes their precise study extremely complex. In fact, the macroscopic behavior of these materials is strongly dependent on mechanisms that act to the scale of their components. The present work focus on the development of a macroscopic conductive and convective fluid heat transfer model, with a heat source in the unsaturated porous materials. This model is established by periodic homogenization of energy conservation equations written on a microscopic scale in each phase (solid, liquid and gas). The resulting input parameters formulations of the submodel were explicitly identified. Numerical calculations of the homogenized thermal conductivity tensor are performed on a representative 3-D elementary cell of the porous medium. Finally, a sensitivity study of this tensor depending of the variation of the water content and porosity of the concerned elementary cell has been performed. This sensitivity is required to be considered in simulations to better understand the behavior of building materials and improve the prediction of energy performance.

scholarly journals USING ADOBE (CLAY SOIL) MIXED WITH QUARTZ (SHARP SAND) TO DETERMINE THE THERMAL COMFORT OF RESIDENTIAL BUILDING IN NORTH-MUBI L. G, ADAMAWA STATE, NIGERIA

2019 ◽  
Vol 7 (3) ◽  
pp. 274-281
Author(s):  
S. K Singh ◽  
H. P Wante ◽  
S. M Ngaram
Keyword(s):  
Thermal Conductivity ◽  
Building Materials ◽  
Residential Buildings ◽  
Residential Building ◽  
Energy Materials ◽  
Need For Power ◽  
Hot Arid Climate ◽  
Materials Used ◽  
Made In ◽  
Thermal Conductivities

The adobe structure is constructed by using low energy materials like adobe soil and sand etc. Adobe and cob are terms often used to describe sun dried clay materials. Adobe is a Spanish word derived from the Arabic atob, which literally means sun dried bricks.This paper investigated the thermal conductivity of Adobe mixed with Quartz in view of their availability usage as building materials. The thermal conductivities of disc made from Adobe-Quartz chippings were determined, the values obtained were between 0.57Wm-1k-1 and 0.91Wm-1k-1, and these values could be used to identify Adobe-Quartz as one of the engineering materials used in building construction, adopted to reduce the temperature of buildings without the need for power consumption. Consequently, the aim of this study is to test the usefulness of applying selected Adobe-Quartz to improve thermal performance and to reduce energy consumption of residential buildings in hot arid climate setting, Mubi, Adamawa State, Nigeria. Energy reduction was achieved by making the Adobe-Quartz into bricks used as aggregates in walls. Adobe-Quartz was made in disc form of the same thickness and diameter, by proportions of Adobe to Quartz (90:10, 85:15, 80:20), i.e. 10 samples for each ratio. The average values of the thermal conductivities were between 0.07Wm-1k-1 and 0.93Wm-1k-1, the least thermal conductivity value was 0.57Wm-1k-1 for the ratio of (90:10). MATLAB 7.0 and EXCEL software were used in the various computations. An average correlation coefficient, R2 of 0.75 was existed between Adobe-Quartz ratios to thermal conductivities.

scholarly journals Energy Rating of Buildings to Promote Energy-Conscious Design in Israel

Buildings ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 59
Author(s):  
Abraham Yezioro ◽  
Isaac Guedi Capeluto
Keyword(s):  
Design Process ◽  
Architectural Design ◽  
Residential Building ◽  
Green Building ◽  
Energy Performance ◽  
Basic Unit ◽  
Design Stage ◽  
Design Decision ◽  
Rating Systems ◽  
New Buildings

Improving the energy efficiency of existing and new buildings is an important step towards achieving more sustainable environments. There are various methods for grading buildings that are required according to regulations in different places for green building certification. However, in new buildings, these rating systems are usually implemented at late design stages due to their complexity and lack of integration in the architectural design process, thus limiting the available options for improving their performance. In this paper, the model ENERGYui used for design and rating buildings in Israel is presented. One of its main advantages is that it can be used at any design stage, including the early ones. It requires information that is available at each stage only, as the additional necessary information is supplemented by the model. In this way, architects can design buildings in a way where they are aware of each design decision and its impact on their energy performance, while testing different design directions. ENERGYui rates the energy performance of each basic unit, as well as the entire building. The use of the model is demonstrated in two different scenarios: an office building in which basic architectural features such as form and orientation are tested from the very beginning, and a residential building in which the intervention focuses on its envelope, highlighting the possibilities of improving their design during the whole design process.

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