scholarly journals Impact of Insulation Type and Thickness on the Dynamic Thermal Characteristics of an External Wall Structure

2018 ◽  
Vol 10 (8) ◽  
pp. 2835 ◽  
Author(s):  
Jihui Yuan
Keyword(s):  
Time Lag ◽  
Thermal Characteristics ◽  
Thermal Capacity ◽  
Wall Structure ◽  
External Wall ◽  
Thermal Transmittance ◽  
Wall Structures ◽  
The Impact ◽  
Time Lead ◽  
Surface Factor

The dynamic thermal characteristics of external wall structures are directly related to indoor thermal comfort and energy savings in buildings; they are also complicated and worth investigating. Thermal insulation in external wall structures has become a popular topic of investigation in the domain of building energy efficiency. This study aims to find the impact of insulation type and thickness on the dynamic thermal characteristics of external wall structures using a homogeneous multi-layer building external wall structure and three types of insulation materials that are widely used in Japan. The impact of insulation type and thickness on seven thermal characteristics of external walls, including thermal transmittance, decrement factor or amplitude attenuation, time lag, thermal admittance, time lead for thermal admittance, surface factor, and thermal capacity, was evaluated by numerical methods in this study. It was shown that insulation type and thickness would have a significant effect on thermal transmittance, decrement factor and time lag, but yield no significant change in thermal admittance, time lead for thermal admittance, surface factor, and the thermal capacity of external wall structures.

Analysis of dynamic thermal performance of the walls in residential buildings in Serbia

2020 ◽  
pp. 095440622094189
Author(s):  
Saša M Kalinović ◽  
Jelena M Djoković
Keyword(s):  
Thermal Performance ◽  
Residential Buildings ◽  
Thermal Characteristics ◽  
Optimal Solution ◽  
Temperature Oscillation ◽  
Thermal Capacity ◽  
Paper Analysis ◽  
Wall Structure ◽  
Total Thickness ◽  
External Temperature

In this paper, analysis of dynamic thermal performance of multilayer insulation wall in residential buildings in Serbia is performed. Considering that the final goal is to build a residential structure with the highest level of efficiency, that is, with the lowest energy consumption for heating and cooling, it is necessary to determine good thermal characteristics of a multilayer wall. The first type of walls, which were analyzed had the same structure with different thicknesses of individual layers. The second type of analyzed walls had the same structure, but the thermo-insulating layers occupied different positions. The third type of walls had different structures, but the same total thickness. Based on the results presented in the paper, it can be concluded that in walls with similar structures, the same total thickness and different thicknesses of individual layers, there are differences in the external temperature variation shift. The position of the thermal insulation layer for the same wall structure does not significantly affect the change in temperature oscillation caused by the change in the outside temperature. Changing the wall structure, however, has significant influence on the thermal capacity. This analysis offers the possibility to choose the optimal solution for the wall structure with the highest energy efficiency.

scholarly journals Thermal Behavior and Measures to Prevent Condensation of a Newly Developed External Wall Panel

2019 ◽  
Vol 11 (3) ◽  
pp. 912 ◽  
Author(s):  
Goopyo Hong ◽  
Suk-Won Lee ◽  
Ji-Yeon Kang ◽  
Hyung-Geun Kim
Keyword(s):  
Surface Temperature ◽  
Thermal Performance ◽  
Simulation Analysis ◽  
Thermal Characteristics ◽  
Weather Conditions ◽  
Building Envelope ◽  
Unsteady State ◽  
Wall Panel ◽  
External Wall ◽  
Thermal Transmittance

An external wall panel (EWP) as a novel alternative to provide spatial flexibility and improve the performance of external walls was developed. The purpose of this study was to analyze the thermal performance of this EWP. A simulation analysis was carried out to scrutinize whether it was vulnerable to condensation, considering South Korea’s weather conditions, and find countermeasures to prevent this. Results indicated that the indoor surface temperature with the measures of added insulation materials and an inserted thermal-breaker was over 16.5 °C and that these methods could prevent condensation. In addition, this study assessed unsteady-state thermal characteristics, linear thermal transmittance, and the effective thermal transmittance of EWP. Effective thermal transmittance was estimated in consideration of the heat transmittance of EWP and the linear thermal transmittance of its slabs and its connection parts. The thermal characteristics of the building envelope are needed to analyze effective thermal transmittance and linear thermal transmittance-associated thermal bridges.

scholarly journals Calculation of the Thermal Dynamic Performance of the Residential Buildings’ Walls

2019 ◽  
Vol 1 (1) ◽  
pp. 212-221
Author(s):  
Saša M. Kalinović ◽  
Jelena M. Djoković ◽  
Ružica R. Nikolić ◽  
Branislav Hadzima
Keyword(s):  
Dynamic Properties ◽  
Residential Buildings ◽  
Dynamic Performance ◽  
Thermal Characteristics ◽  
Optimal Solution ◽  
Wall Structure ◽  
Efficiency Ratio ◽  
Heating And Cooling ◽  
Wall Structures ◽  
The Individual

Abstract Calculation of the thermal dynamic properties of the multi-layer wall isolation of residential buildings is presented in this paper. Taking into account that the final objective is to create a building with the highest energy efficiency ratio, i.e. with the lowest energy consumption, both for heating and cooling, it is necessary to realize the good thermal characteristics of the multi-layer wall. To obtain the optimal solution for the wall's structure, various wall structures with different thicknesses of the individual layers, were analyzed. Based on results, presented in this paper, one can conclude that for walls with the same total thickness, but various thicknesses of the individual layers, that constitute the complete wall structure, the differences appear in the delay of the change of the walls outside temperature. In that way, by varying those individual layers' thicknesses, one can obtain the optimal solution for the wall structure with the highest savings of energy.

Frame - Shear Wall Structures Subjected to Vertical Deformation and the Shrinkage and Creep of Concrete Relations

2012 ◽  
Vol 166-169 ◽  
pp. 3403-3407
Author(s):  
Lin Pan ◽  
Li Wei Zhang
Keyword(s):  
Shear Wall ◽  
Wall Structure ◽  
Vertical Deformation ◽  
Concrete Creep ◽  
Analysis And Design ◽  
High Rise ◽  
Wall Structures ◽  
Internal Forces ◽  
The Difference ◽  
The Impact

Frame - shear wall structural system are widely used in high-rise buildings . During the construction period , a different pressure than due to the loads and their respective axis , resulting in the existence of vertical deformation of the difference between the components , this difference will frame - shear wall structure beams internal forces have an important impact . The existence of concrete creep and shrinkage , so that the impact of further increase . A frame - shear wall structure high-rise buildings for the analysis object , using the finite element method , and analyze the impact of contraction of the construction process of concrete creep frame - shear wall structure of the vertical deformation and internal forces , a number of recommendations for the rationalization for structural analysis and design practical , in order to service engineering

scholarly journals Using Recycled Material from the Paper Industry as a Backfill Material for Retaining Walls near Railway Lines

2021 ◽  
Vol 13 (2) ◽  
pp. 979
Author(s):  
Karmen Fifer Bizjak ◽  
Barbara Likar ◽  
Stanislav Lenart
Keyword(s):  
Retaining Wall ◽  
Paper Industry ◽  
Time Lag ◽  
Wall Structure ◽  
Railway Line ◽  
Backfill Material ◽  
Geotechnical Structures ◽  
Sludge Ash ◽  
The Impact ◽  
Recycled Material

The construction industry uses a large amount of natural virgin material for different geotechnical structures. In Europe alone, 11 million tonnes of solid waste is generated per year as a result of the production of almost 100 million tonnes of paper. The objective of this research is to develop a new geotechnical composite from residues of the deinking paper industry and to present its practical application, e.g., as a backfill material behind a retaining structure. After different mixtures were tested in a laboratory, the technology was validated by building a pilot retaining wall structure in a landslide region near a railway line. It was confirmed that a composite with 30% deinking sludge and 70% deinking sludge ash had a high enough strength but experienced some deformations before failure. Special attention was paid to the impact of transport, which, due to the time lag between the mixing and installation of the composite, significantly reduced its strength. The pilot retaining wall structure promotes the use of recycled materials with a sustainable design, while adhering to government-mandated measures.

Numerical Simulation of the Effect of the Uneven Wall on the Liquid Film Flow

2013 ◽  
Vol 477-478 ◽  
pp. 232-235
Author(s):  
Mei Liu ◽  
Yongxin Zhu ◽  
Song Ling Wang
Keyword(s):  
Liquid Film ◽  
Film Flow ◽  
Flow Characteristics ◽  
Wave Profile ◽  
Wall Structure ◽  
Wavy Wall ◽  
Continuous Film ◽  
Wall Structures ◽  
Liquid Film Flow ◽  
The Impact

Two-dimensional models of inclined flat and corrugated walls are established based on VOF method to numerically simulate the flow characteristics of liquid film. The impact of wall structures on the wave profile of the film is studied. The results indicate that the wall structure plays an important role on the liquid film, there are vortexes generated on the trough of wavy wall, the vortex has the "rolling" effect in machinery, which reduces the viscous resistance. and continuous film is easier to form on the wall whose corrugated size is smaller.

scholarly journals A Fundamental Study on the Development of New Energy Performance Index in Office Buildings

Energies ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2064
Author(s):  
Jin-Hee Kim ◽  
Seong-Koo Son ◽  
Gyeong-Seok Choi ◽  
Young-Tag Kim ◽  
Sung-Bum Kim ◽  
...  
Keyword(s):  
Energy Consumption ◽  
Energy Requirement ◽  
Energy Performance ◽  
Office Buildings ◽  
Light Transmittance ◽  
Wall Structure ◽  
Fundamental Study ◽  
Future Studies ◽  
U Value ◽  
The Impact

Recently, there have been significant concerns regarding excessive energy use in office buildings with a large window-to-wall ratio (WWR) because of the curtain wall structure. However, prior research has confirmed that the impact of the window area on energy consumption varies depending on building size. A newly proposed window-to-floor ratio (WFR) correlates better with energy consumption in the building. In this paper, we derived the correlation by analyzing a simulation using EnergyPlus, and the results are as follows. In the case of small buildings, the results of this study showed that the WWR and energy requirement increase proportionally, and the smaller the size is, the higher the energy sensitivity will be. However, results also confirmed that this correlation was not established for buildings approximately 3600 m2 or larger. Nevertheless, from analyzing the correlation between the WFR and the energy requirements, it could be deduced that energy required increased proportionally when the WFR was 0.1 or higher. On the other hand, the correlation between WWR, U-value, solar heat gain coefficient (SHGC), and material property values of windows had little effect on energy when the WWR was 20%, and the highest effect was seen at a WWR of 100%. Further, with an SHGC below 0.3, the energy requirement decreased with an increasing WWR, regardless of U-value. In addition, we confirmed the need for in-depth research on the impact of the windows’ U-value, SHGC, and WWR, and this will be verified through future studies. In future studies on window performance, U-value, SHGC, visible light transmittance (VLT), wall U-value as sensitivity variables, and correlation between WFR and building size will be examined.

scholarly journals A comparison between polynya area and associated ice production with mooring-based measurements of temperature, salinity and currents in the southwestern Ross Sea, Antarctica

2011 ◽  
Vol 52 (57) ◽  
pp. 291-300 ◽  
Author(s):  
Stefan Kern ◽  
Stefano Aliani
Keyword(s):  
Ross Sea ◽  
Time Lag ◽  
Ice Formation ◽  
Terra Nova Bay ◽  
In Situ Observations ◽  
Satellite Microwave ◽  
Terra Nova ◽  
Ice Production ◽  
The Impact

AbstractWintertime (April–September) area estimates of the Terra Nova Bay polynya (TNBP), Antarctica, based on satellite microwave radiometry are compared with in situ observations of water salinity, temperature and currents at a mooring in Terra Nova Bay in 1996 and 1997. In 1996, polynya area anomalies and associated anomalies in polynya ice production are significantly correlated with salinity anomalies at the mooring. Salinity anomalies lag area and/or ice production anomalies by about 3 days. Up to 50% of the variability in the salinity at the mooring position can be explained by area and/or ice production anomalies in the TNBP for April–September 1996. This value increases to about 70% when considering shorter periods like April–June or May–July, but reduces to 30% later, for example July–September, together with a slight increase in time lag. In 1997, correlations are smaller, less significant and occur at a different time lag. Analysis of ocean currents at the mooring suggests that in 1996 conditions were more favourable than in 1997 for observing the impact of descending plumes of salt-enriched water formed in the polynya during ice formation on the water masses at the mooring depth.

scholarly journals Insulation Characteristics of Sisal Fibre/Epoxy Composites

2017 ◽  
Vol 2017 ◽  
pp. 1-6 ◽  
Author(s):  
A. Shalwan ◽  
M. Alajmi ◽  
A. Alajmi
Keyword(s):  
Volume Fraction ◽  
Fibre Volume Fraction ◽  
Thermal Characteristics ◽  
Fibre Volume ◽  
Point Of View ◽  
Natural Fibres ◽  
Epoxy Composites ◽  
Ongoing Research ◽  
Sisal Fibre ◽  
The Impact

Using natural fibres in civil engineering is the aim of many industrial and academics sectors to overcome the impact of synthetic fibres on environments. One of the potential applications of natural fibres composites is to be implemented in insulation components. Thermal behaviour of polymer composites based on natural fibres is recent ongoing research. In this article, thermal characteristics of sisal fibre reinforced epoxy composites are evaluated for treated and untreated fibres considering different volume fractions of 0–30%. The results revealed that the increase in the fibre volume fraction increased the insulation performance of the composites for both treated and untreated fibres. More than 200% insulation rate was achieved at the volume fraction of 20% of treated sisal fibres. Untreated fibres showed about 400% insulation rate; however, it is not recommended to use untreated fibres from mechanical point of view. The results indicated that there is potential of using the developed composites for insulation purposes.

Study on the shear wall structure with combined form of replaceable devices

2017 ◽  
Vol 21 (9) ◽  
pp. 1327-1348
Author(s):  
Cong Chen ◽  
Renjie Xiao ◽  
Xilin Lu ◽  
Yun Chen
Keyword(s):  
Shear Walls ◽  
Shear Wall ◽  
Performance Comparison ◽  
Wall Structure ◽  
Structural Part ◽  
Coupled Shear Wall ◽  
Wall Structures ◽  
Strength And Stiffness ◽  
Energy Dissipated ◽  
Resilient Structure

Structure with replaceable devices is a type of earthquake resilient structure developed to restore the structure immediately after strong earthquakes. Current researches focus on one type of the replaceable device located in the structural part that is most likely to be damaged; however, plastic deformation would not be limited in a specific part but expand to other parts. To concentrate possible damage in shear wall structures, combined form of replaceable devices was introduced in this article. Based on previous studies, combined form of replaceable coupling beam and replaceable wall foot was used in a coupled shear wall. Influences of the dimension and location of the replaceable devices to the strength and stiffness of the shear wall were investigated through numerical modeling, which was verified by experimental data. Performance comparison between the shear walls with one type and combined form of replaceable devices and the conventional coupled shear wall was performed. In general, the shear wall with combined form of replaceable devices is shown to be better energy dissipated, and proper dimensions and locations of the replaceable devices should be determined.

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