scholarly journals Thermal bridges in building envelopes – An overview of impacts and solutions

2018 ◽  
Vol 9 (1) ◽  
pp. 31-40 ◽  
Author(s):  
A. Alhawari ◽  
P. Mukhopadhyaya
Keyword(s):  
Experimental Studies ◽  
Building Energy ◽  
Energy Performance ◽  
Building Energy Efficiency ◽  
Thermal Bridge ◽  
Thermal Bridges ◽  
Thermal Bridging ◽  
Negative Impacts ◽  
The Impact

Increasing building energy performance has become an obligatory objective in many countries. Thermal bridge is a major cause of poor energy performance, durability, and indoor air quality of buildings. This paper starts with a review of thermal bridges and their negative impacts on building energy efficiency. Based on published literatures, various types of building thermal bridges are discussed in this paper, including the most effective solutions to diminish their impacts. In addition, various numerical and experimental studies on the balcony thermal bridge are explored. Results show that among all types of thermal bridges, the exposed balcony slab produces the most challenging thermal bridging problem where an integrated thermal and structural design is required. Using low thermal conductivity materials in building construction could help in reducing the impact of thermal bridges. Finally, further investigations are needed to develop more innovative and effective solutions for the balcony thermal bridge.

Thermal Bridges Minimizing through Typical Details in Low Energy Designing

2014 ◽  
Vol 899 ◽  
pp. 62-65 ◽  
Author(s):  
Rastislav Ingeli ◽  
Boris Vavrovič ◽  
Miroslav Čekon
Keyword(s):  
Energy Efficiency ◽  
Thermal Insulation ◽  
Energy Demand ◽  
Building Energy ◽  
Building Envelope ◽  
Low Energy ◽  
Building Energy Efficiency ◽  
Low Energy Buildings ◽  
Thermal Bridges ◽  
The Impact

Energy demand reduction in buildings is an important measure to achieve climate change mitigation. It is essential to minimize heat losses in designing phase in accordance of building energy efficiency. For building energy efficiency in a mild climate zone, a large part of the heating demand is caused by transmission losses through the building envelope. Building envelopes with high thermal resistance are typical for low-energy buildings in general. In this sense thermal bridges impact increases by using of greater thickness of thermal insulation. This paper is focused on thermal bridges minimizing through typical system details in buildings. The impact of thermal bridges was studied by comparative calculations for a case study of building with different amounts of thermal insulation. The calculated results represent a percentage distribution of heat loss through typical building components in correlation of various thicknesses of their thermal insulations.

scholarly journals Editorial: Building integrated renewable energy

2020 ◽  
pp. 014459872095251
Author(s):  
Yaolin Lin ◽  
Wei Yang ◽  
Xiaoli Hao ◽  
Changxiong Yu
Keyword(s):  
Energy Efficiency ◽  
Renewable Energy ◽  
Greenhouse Gas Emission ◽  
Experimental Studies ◽  
Building Energy ◽  
Energy Performance ◽  
Energy Utilization ◽  
Building Energy Efficiency ◽  
Special Issue ◽  
The World

About one-third of the primary energy in the world is consumed by buildings. A large amount of CO2 emission due to building energy consumption has threatened the sustainable development of the world. Improvement on the building energy performance, especially by integration with renewable energy resources has attracted interest worldwide to reduce greenhouse gas emission to make our society more sustainable. This Special Issue on building integrated renewable energy was open to all contributors in the field of building energy efficiency. The original experimental studies, numerical simulations, and reviews in all aspects of renewable energy utilization, management, and optimization have been considered. In the event, all these topics were covered in the extensive submissions accepted, but interesting papers on other aspects of building energy efficiency were also received. The purpose of this editorial is to summarize the main research findings of accepted papers in this Special Issue, including the use of renewable energy and energy saving technologies in buildings and identify a number of research questions and research directions.

scholarly journals Evaluation of Urban-Scale Building Energy-Use Models and Tools—Application for the City of Fribourg, Switzerland

2021 ◽  
Vol 13 (4) ◽  
pp. 1595
Author(s):  
Valeria Todeschi ◽  
Roberto Boghetti ◽  
Jérôme H. Kämpf ◽  
Guglielmina Mutani
Keyword(s):  
Machine Learning ◽  
Energy Use ◽  
Residential Buildings ◽  
Building Energy ◽  
Energy Performance ◽  
Space Heating ◽  
Engineering Model ◽  
Building Energy Use ◽  
The Impact ◽  
The City

Building energy-use models and tools can simulate and represent the distribution of energy consumption of buildings located in an urban area. The aim of these models is to simulate the energy performance of buildings at multiple temporal and spatial scales, taking into account both the building shape and the surrounding urban context. This paper investigates existing models by simulating the hourly space heating consumption of residential buildings in an urban environment. Existing bottom-up urban-energy models were applied to the city of Fribourg in order to evaluate the accuracy and flexibility of energy simulations. Two common energy-use models—a machine learning model and a GIS-based engineering model—were compared and evaluated against anonymized monitoring data. The study shows that the simulations were quite precise with an annual mean absolute percentage error of 12.8 and 19.3% for the machine learning and the GIS-based engineering model, respectively, on residential buildings built in different periods of construction. Moreover, a sensitivity analysis using the Morris method was carried out on the GIS-based engineering model in order to assess the impact of input variables on space heating consumption and to identify possible optimization opportunities of the existing model.

scholarly journals Impact of Window to Wall Ratio on Energy Loads in Hot Regions: A Study of Building Energy Performance

Energies ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 1080
Author(s):  
Mamdooh Alwetaishi ◽  
Omrane Benjeddou
Keyword(s):  
Saudi Arabia ◽  
Building Materials ◽  
Building Design ◽  
Building Energy ◽  
Energy Performance ◽  
Design Stage ◽  
Design Solution ◽  
Building Energy Efficiency ◽  
Climatic Regions ◽  
Heating And Cooling

The concern regarding local responsive building design has gained more attention globally as of late. This is due to the issue of the rapid increase in energy consumption in buildings for the purpose of heating and cooling. This has become a crucial issue in educational buildings and especially in schools. The major issue in school buildings in Saudi Arabia is that they are a form of prototype school building design (PSBD). As a result, if there is any concern in the design stage and in relation to the selection of building materials, this will spread throughout the region. In addition to that, the design is repeated regardless of the climate variation within the kingdom of Saudi Arabia. This research will focus on the influence of the window to wall ratio on the energy load in various orientations and different climatic regions. The research will use the energy computer tool TAS Environmental Design Solution Limited (EDSL) to calculate the energy load as well as solar gain. During the visit to the sample schools, a globe thermometer will be used to monitor the globe temperature in the classrooms. This research introduces a framework to assist architects and engineers in selecting the proper window to wall ratio (WWR) in each direction within the same building based on adequate natural light with a minimum reliance on energy load. For ultimate WWR for energy performance and daylight, the WWR should range from 20% to 30%, depending on orientation, in order to provide the optimal daylight factor combined with building energy efficiency. This ratio can be slightly greater in higher altitude locations.

scholarly journals A Study of Optimal Specifications for Light Shelves with Photovoltaic Modules to Improve Indoor Comfort and Save Building Energy

2021 ◽  
Vol 18 (5) ◽  
pp. 2574
Author(s):  
Heangwoo Lee ◽  
Xiaolong Zhao ◽  
Janghoo Seo
Keyword(s):  
Energy Savings ◽  
Building Energy ◽  
Energy Performance ◽  
Building Energy Efficiency ◽  
Efficiency Change ◽  
Photovoltaic Modules ◽  
Heating And Cooling ◽  
Pv Module ◽  
Pv Modules ◽  
Indoor Comfort

Recent studies on light shelves found that building energy efficiency could be maximized by applying photovoltaic (PV) modules to light shelf reflectors. Although PV modules generate a substantial amount of heat and change the consumption of indoor heating and cooling energy, performance evaluations carried out thus far have not considered these factors. This study validated the effectiveness of PV module light shelves and determined optimal specifications while considering heating and cooling energy savings. A full-scale testbed was built to evaluate performance according to light shelf variables. The uniformity ratio was found to improve according to the light shelf angle value and decreased as the PV module installation area increased. It was determined that PV modules should be considered in the design of light shelves as their daylighting and concentration efficiency change according to their angles. PV modules installed on light shelves were also found to change the indoor cooling and heating environment; the degree of such change increased as the area of the PV module increased. Lastly, light shelf specifications for reducing building energy, including heating and cooling energy, were not found to apply to PV modules since PV modules on light shelf reflectors increase building energy consumption.

scholarly journals Impact of eating disorders on paid or unpaid work participation and performance: a systematic review and meta-analysis protocol

2022 ◽  
Vol 10 (1) ◽  
Author(s):  
Fatima Safi ◽  
Anna M. Aniserowicz ◽  
Heather Colquhoun ◽  
Jill Stier ◽  
Behdin Nowrouzi-Kia
Keyword(s):  
Systematic Review ◽  
Eating Disorders ◽  
Meta Analysis ◽  
Experimental Studies ◽  
Work Participation ◽  
Unpaid Work ◽  
Cochrane Library ◽  
And Performance ◽  
The Impact

Abstract Background Eating disorders (ED) can reduce quality of life by limiting participation and performance in social and occupational roles, including paid or unpaid work. The association between ED pathologies and work participation and performance must be well understood to strengthen vocational rehabilitation programmes and prevent occupational disruptions in the ED population. The aims of this study are: (1) to examine the degree of association between ED pathologies and work participation and performance in 15-year-olds and older; (2) to highlight the specific ED symptoms that are most correlated with changes in work performance and participation; (3) to compile the most common metrics and assessments used to measure work participation and performance with ED. Methods Medline, Embase, CINAHL, Web of Science, PsycINFO, and Cochrane Library will be searched for observational and experimental studies that meet the following criteria: (1) a clinical sample of typical or atypical ED; (2) paid or unpaid employment or training; (3) an association between ED pathologies and work participation or performance. Unpublished data will also be examined. Title and abstract, and full-text screening will be conducted in duplicate. Risk of bias and quality of evidence assessments will be completed. A random-effect meta-analysis will be performed. Discussion This synthesis can clarify knowledge and gaps around the impact of ED on work functioning, thereby allowing better evaluation, improvements and development of current workplace assessments, interventions, and policies. Trial registration The registration number for this systematic review on PROSPERO is CRD42021255055.

Upgrading the Building Facades in Low-Density Residential Areas

2020 ◽  
pp. 216-243
Author(s):  
Katerina Tsikaloudaki ◽  
Dimitra Tsirigoti ◽  
Stella Tsoka ◽  
Theodore Theodosiou
Keyword(s):  
Energy Performance ◽  
Building Envelope ◽  
Building Performance ◽  
Residential Areas ◽  
Energy Needs ◽  
Building Facades ◽  
Thermal Bridging ◽  
Negative Impacts ◽  
Building Physics ◽  
Common Action

The most common action for the buildings' energy upgrade across Europe is the addition of thermal insulation on the external walls. Such interventions, although simple on their construction, cause significant changes on the building's behavior, not only on its energy needs, but also on the hygrothermal and visual performance. The effects are not always positive; for example, thicker insulation may result in lower thermal transmittance and better thermal energy performance, but on the other hand the thermal bridging effect is amplified, and the daylight levels are decreased. This research intends to quantify these impacts by analyzing the relevant parameters for different regions of Europe. The analysis aims at explaining the complicated interrelationships on the building physics' aspects encountered through interventions on the building envelope, but also at identifying appropriate measures that could counterbalance the negative impacts and enhance the overall building performance.

Exploring mass customization and textile application in medical products: re-designing scoliosis brace for shorter production lead time and better quality of life

2020 ◽  
Vol 90 (19-20) ◽  
pp. 2304-2321
Author(s):  
Olivia Ho-Yi Fung ◽  
Joanne Yip ◽  
Mei-Chun Cheung ◽  
Kit-Lun Yick ◽  
Kenny Yat-Hong Kwan ◽  
...  
Keyword(s):  
Quality Of Life ◽  
Patient Compliance ◽  
Mass Customization ◽  
Lead Time ◽  
Interface Pressure ◽  
Negative Impacts ◽  
Exerted Pressure ◽  
The Impact

Bracing is the most common non-operative treatment option for patients with adolescent idiopathic scoliosis (AIS). However, existing brace designs have deficiencies, including a long production lead time and low patient compliance caused by the negative impacts of bracing on quality of life (QoL). The aim of this study was to address these problems by developing a new textile-based scoliosis brace in accordance with the biomechanics used in the existing braces for spinal correction. A case study of interface pressure had been carried out to determine the optimum combination of pads to be used in the proposed brace to correct a scoliotic spine. AIS patients who were undergoing hard brace treatment were recruited to complete a questionnaire (BrQ) on hard braces and on the proposed brace. The BrQ scores of the two types of braces were compared to assess their respective impacts on the QoL. The findings show that the proposed brace can address the issue of patient compliance by reducing the impact of bracing on QoL, and shorten the production lead time through incorporation of the mass customization concept into the design. Similar to most of the commonly-used scoliosis braces, the selected combination of pads used in the proposed brace for spinal correction shows a sufficient amount of exerted pressure and a similar function of active spinal correction.

scholarly journals The Influence of Different Facings of Polyisocyanurate Boards on Heat Transfer through the Wall Corners of Insulated Buildings

Energies ◽  
2020 ◽  
Vol 13 (8) ◽  
pp. 1991 ◽  
Author(s):  
Tomas Makaveckas ◽  
Raimondas Bliūdžius ◽  
Arūnas Burlingis
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Heat Flux ◽  
Thermal Insulation ◽  
Transfer Coefficients ◽  
Heat Transfer Coefficients ◽  
Thermal Bridge ◽  
Thermal Bridges ◽  
The Impact ◽  
Heat Flow Meter

Polyisocyanurate (PIR) thermal insulation boards faced with carboard, plastic, aluminum, or multilayer facings are used for thermal insulation of buildings. Facing materials are selected according to the conditions of use of PIR products. At the corners of the building where these products are joined, facings can be in the direction of the heat flux movement and significantly increase heat transfer through the linear thermal bridge formed in the connection of PIR boards with facing of both walls. Analyzing the installation of PIR thermal insulation products on the walls of a building, the structural schemes of linear thermal bridges were created, numerical calculations of the heat transfer coefficients of the linear thermal bridges were performed, and the influence of various facings on the heat transfer through the thermal bridge was evaluated. Furthermore, an experimental measurement using a heat flow meter apparatus was performed in order to confirm the results obtained by numerical calculation. This study provides more understanding concerning the necessity to evaluate the impact of different thermal conductivity facings on the heat transfer through corners of buildings insulated with PIR boards.

scholarly journals Selected Properties of the Surface Layer of C45 Steel Parts Subjected to Laser Cutting and Ball Burnishing

Materials ◽  
2020 ◽  
Vol 13 (15) ◽  
pp. 3429 ◽  
Author(s):  
Agnieszka Skoczylas ◽  
Kazimierz Zaleski
Keyword(s):  
Surface Layer ◽  
Residual Stresses ◽  
Laser Cutting ◽  
Experimental Studies ◽  
Hardened Layer ◽  
Ball Burnishing ◽  
Absolute Value ◽  
The Impact ◽  
Compressive Residual Stresses

In this article, we report the results of experimental studies on the impact of ball burnishing parameters on the roughness, microstructure and microhardness of the surface layer of laser-cut C45 steel parts. We also analysed the distribution of residual stresses generated in the surface layer of these parts. Laser-cut parts often require finishing to improve the quality of their surface. The tests performed in this study were aimed at assessing whether ball burnishing could be used as a finishing operation for parts of this type. Ball burnishing tests were performed on an FV-580a vertical machining centre using a mechanically controlled burnishing tool. The following parameters were varied during the ball burnishing tests: burnishing force Fn, path interval fw and the diameter of the burnishing ball dn. Ball burnishing of laser-cut C45 steel parts reduced the surface roughness parameters Sa and Sz by up to 60% in relation to the values obtained after laser cutting. Finish machining also led to the reorganization of the geometric structure of the surface, resulting in an increase in the absolute value of skewness Ssk. This was accompanied by an increment in microhardness (maximum microhardness increment was ΔHV = 95 HV0.05, and the thickness of the hardened layer was gh = 40 µm) and formation of compressive residual stresses in the surface layer.

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