scholarly journals Patents Analysis of Thermal Bridges in Slab Fronts and Their Effect on Energy Demand

Energies ◽  
2018 ◽  
Vol 11 (9) ◽  
pp. 2222 ◽  
Author(s):  
David Bienvenido-Huertas ◽  
Juan Antonio Fernández Quiñones ◽  
Juan Moyano ◽  
Carlos E. Rodríguez-Jiménez
Keyword(s):  
Energy Demand ◽  
Heat Losses ◽  
Global Energy ◽  
Thermal Transmittance ◽  
Thermal Bridge ◽  
Energy Behaviour ◽  
Current Scenario ◽  
Thermal Bridges ◽  
Pollutant Gases

Nowadays, the building sector is one of the main sources emitting pollutant gases to the atmosphere due to its deficient energy behaviour. Among the elements of the envelope, the thermal bridges are where the heat losses and gains mainly occur, depending on the season of the year. To reduce the effect of the thermal bridges, there are different patented technologies which give provide solutions. In this paper, the thermal behaviour of five patented slab front (slab-façade) thermal bridges are analysed in a case study located in the south of Spain. Moreover, the influence of the thermal bridge on the energy demand from the building analysed was evaluated, both in the current scenario and future ones (2020, 2050 and 2080). The results reveal that the use of the patents in slab fronts can mean reductions by up to 95.74% in the linear thermal transmittance. Likewise, due to the improvement of the thermal bridge of slab fronts by using the patented designs which offered the best features, a savings in the global energy demand for heating higher than 18% as well as a savings in the global energy demand for cooling higher than 2.80% could be achieved in all the time scenarios considered.

scholarly journals Performance Evaluation of Thermal Bridge Reduction Method for Balcony in Apartment Buildings

Buildings ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 63
Author(s):  
Xinwen Zhang ◽  
Gun-Joo Jung ◽  
Kyu-Nam Rhee
Keyword(s):  
Heat Loss ◽  
Energy Demand ◽  
Residential Buildings ◽  
Thermal Transmittance ◽  
Apartment Buildings ◽  
Energy Demands ◽  
Thermal Bridge ◽  
Reinforced Polymer ◽  
Insulation Systems ◽  
Thermal Bridges

Most apartment buildings in South Korea use internal insulation systems to reduce building energy demand. However, thermal bridges such as balcony slabs in apartment buildings still lead to significant heat loss in winter, because the internal insulation system is not continuous in the balcony slab structure, and floor heating systems are commonly used in residential buildings. Therefore, this study investigates two types of thermal break elements, namely thermal break (TB) and thermal break-fiber glass reinforced polymer (TB-GFRP), to improve the thermal resistance of a balcony thermal bridge. To understand the effects of balcony thermal bridges with and without thermal break elements, the linear thermal transmittances of different balcony thermal bridges were analyzed using Physibel simulations. Then, the heating demand of a model apartment under varying thermal bridge conditions was evaluated using TRNSYS simulations. To understand the effect of insulation systems on heat loss through a balcony thermal bridge, apartments with internal and external insulation systems were studied. Whether the apartment was heating was also considered in the thermal transmittance analysis. Thus, the linear thermal transmittance of the thermal bridges with thermal break elements was reduced by more than 60%, and the heating energy demands were reduced by more than 8%.

scholarly journals CASE-STUDY ANALYSIS OF CONCRETE LARGE-PANEL APARTMENT BUILDING AT PRE- AND POST LOW-BUDGET ENERGY-RENOVATION

2016 ◽  
Vol 23 (1) ◽  
pp. 67-75 ◽  
Author(s):  
Kalle KUUSK ◽  
Targo KALAMEES ◽  
Siim LINK ◽  
Simo ILOMETS ◽  
Alo MIKOLA
Keyword(s):  
Co2 Concentration ◽  
Building Envelope ◽  
Study Analysis ◽  
Indoor Climate ◽  
Apartment Building ◽  
Case Study Analysis ◽  
Thermal Transmittance ◽  
Large Panel ◽  
Thermal Bridges

The paper presents a case study analysis of low-budget renovation of a typical concrete large-panel apartment building. Focus is on the measurements and analyses of energy consumption, indoor climate, CO2 concentration, air leakage rate, thermal transmittance of thermal bridges, and thermal transmittance of the building envelope before and after the renovation. Results indicate that the renovation project was generally successful, with delivered energy need de­creasing by 40% and heating energy need decreasing by 50%. However, some key problems need to be solved to achieve full energy efficiency potential of the renovation works. Those critical problems are the performance (thermal comfort, heat recovery) of ventilation systems, thermal bridges of external wall/window jamb and economic viability. Currently, a major renovation is not economically viable, therefore financial assistance to the apartment owners’ associations is required to encourage them to undertake major renovations.

scholarly journals A new method to estimate point thermal transmittance based on combined two-dimensional heat flow calculation

2020 ◽  
Vol 172 ◽  
pp. 08005
Author(s):  
Jaanus Hallik ◽  
Targo Kalamees
Keyword(s):  
Heat Flow ◽  
Three Dimensional ◽  
Multiple Linear Regression Model ◽  
Building Envelope ◽  
New Method ◽  
Two Dimensional ◽  
Thermal Transmittance ◽  
Thermal Bridge ◽  
Thermal Bridges ◽  
Third Dimension

A well-insulated, airtight and thermal bridge free building envelope is a key factor for nearly zero energy buildings (nZEB). However, increased insulation thickness and minimized air leakages increase the effect of thermal bridges on overall energy efficiency of the nZEBs. Although several more prominent linear thermal bridges are accounted for in the practice the three-dimensional heat flow through vast array of fixation elements, mounting brackets and other point thermal bridges are usually neglected due to time-consuming model preparation routine, lack of input data as well as high number of different thermal bridges that have to be assessed for a single project. In this study a new method was proposed for predicting three-dimensional heat flow and the point thermal transmittance of thermal bridges caused by full or partial penetration of the building envelope with metal elements with uniform geometry in third dimension based on multiple two-dimensional numerical heat flow calculations. A new parameter (equivalent length of thermal bridge) was defined which incorporates the effect of additional thermal transmittance in third dimension when multiplied by the difference of two thermal coupling coefficients derived for two-dimensional cross section. Multiple linear regression model was fitted on database with 102 cases and verified with separate case of window to wall connection incorporating metal penetration at fixation points. The proposed methodology can be useful in general practice where the design team lacks the skills or software tools for conducting detailed numerical analysis in three dimensions.

scholarly journals Residential Energy Conservation using Efficient Home Appliances

2020 ◽  
Vol 9 (3) ◽  
pp. 3457-3465
Keyword(s):  
Energy Consumption ◽  
Cost Saving ◽  
Natural Environment ◽  
Energy Demand ◽  
Residential Energy ◽  
Global Energy ◽  
Residential Sector ◽  
Modern House ◽  
Reducing Energy

Significant hike in global energy demand has laid extra pressure on energy generation plants and natural environment as well. Therefore, methods of reducing the global energy demand are being extensively explored worldwide. In this paper, we have discussed ways of reducing energy consumption in Residential sector. We have taken eight major appliances being used in homes and compared them on the basis of annual energy consumed and cost saving by taking suitable assumptions like running hours, seasons of operation, etc. Finally, Case study of a modern house in Aligarh district of UP is studied for analysing the percentage consumption of each appliance being discussed. The results show that appliances like light bulbs, ceiling fans and refrigerators have the highest potential of energy as well as cost saving by improving their efficiency. Further, by switching all the appliances from conventional to the most efficient models resulted in energy and cost saving of about 37% in the house taken for case study.

scholarly journals Instantaneous field measurements of thermal bridge parameters in ground floor residential room

2019 ◽  
Vol 112 ◽  
pp. 01016 ◽  
Author(s):  
Martin Ivanov
Keyword(s):  
Energy Demand ◽  
Field Measurements ◽  
Building Design ◽  
Building Envelope ◽  
Ground Floor ◽  
Thermal Bridge ◽  
Significant Temperature ◽  
Thermal Bridges ◽  
Infrared Thermal Images ◽  
Heating Energy Demand

The “thermal bridges” are defined as an isolated building’s areas, where the construction elements have higher thermal conductivity, compared with the rest of the building envelope. Thus, at cold winter conditions, a significant temperature difference may occur between neighbouring solid and air volumes within the construction. Moreover, it has been documented, that the heating energy demand of a building may be increased with more than 30%, due to the existence of thermal bridges and the increased heat losses from the indoors. Consequently, in the recent years, norms and standards have been developed, for avoiding thermal bridges during the building design process. But still, thermal bridges exist in the indoor environment, especially in older buildings, where no energy efficient measures have been applied. That is why, the presented study focuses on instantaneous field measurements of thermal bridge parameters in real existing ground floor residential room. The thermal bridge propagation is analysed relative to the indoor and outdoor air temperature and relative humidity, as well as with infrared thermal images of the affected external walls. The achieved results give valuable information about the generic conditions for thermal bridge existence, without considering the building envelope properties.

scholarly journals Impact of Shape Factor on Energy Demand, CO2 Emissions and Energy Cost of Residential Buildings in Cold Oceanic Climates: Case Study of South Chile

2021 ◽  
Vol 13 (17) ◽  
pp. 9491
Author(s):  
Manuel Carpio ◽  
David Carrasco
Keyword(s):  
Co2 Emissions ◽  
Shape Factor ◽  
Energy Demand ◽  
Architectural Design ◽  
Residential Buildings ◽  
Thermal Transmittance ◽  
Energy Demands ◽  
Oceanic Climate ◽  
The Impact

The increase in energy consumption that occurs in the residential sector implies a higher consumption of natural resources and, therefore, an increase in pollution and a degradation of the ecosystem. An optimal use of materials in the thermal envelope, together with efficient measures in the passive architectural design process, translate into lower energy demands in residential buildings. The objective of this study is to analyse and compare, through simulating different models, the impact of the shape factor on energy demand and CO2 emissions depending on the type of construction solution used in the envelope in a cold oceanic climate in South Chile. Five models with different geometries were considered based on their relationship between exposed surface and volume. Additionally, three construction solutions were chosen so that their thermal transmittance gradually complied with the values required by thermal regulations according to the climatic zone considered. Other parameters were equally established for all simulations so that their comparison was objective. Ninety case studies were obtained. Research has shown that an appropriate design, considering a shape factor suitable below 0.767 for the type of cold oceanic climate, implies a decrease in energy demand, which increased when considering architectural designs in the envelope with high values of thermal resistance.

scholarly journals A Comparative Study between Jordanian Overall Heat Transfer Coefficient (U-Value) and International Building Codes, With Thermal Bridges Effect Investigation

2021 ◽  
Vol 3 (1) ◽  
pp. p10
Author(s):  
Ammar Alkhalidi ◽  
Suhil Kiwan ◽  
Haya Hamasha
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Energy Demand ◽  
Building Envelope ◽  
Overall Heat Transfer Coefficient ◽  
Thermal Bridge ◽  
U Value ◽  
Thermal Bridges ◽  
Heating Degree Days

Depletion of fossil fuel and the environmental effect associated with the use of it have made the topic of “thermal insulation regulations” a major concern in country Jordan and worldwide. This paper reviews the overall heat transfer coefficient U-value in Jordanian code for the building envelope, which represents how much the building envelope transfer heat to the outside environment. U-value was reviewed with respect to the following factors, heating degree days, the heating load required to achieve thermal comfort. Based on the review a new U-value of 0.65 W/m2.K was proposed and it was found that this value reduces the energy demand almost 50%. Moreover, the thermal bridge effect was investigated and it was found that an obvious increase in the U-value is present when having thermal bridges; this will affect the energy demand, almost 200%.

scholarly journals Impact of point thermal bridges on thermal properties of building envelopes

2020 ◽  
Vol 24 (3 Part B) ◽  
pp. 2181-2188 ◽  
Author(s):  
Jolanta Sadauskiene ◽  
Juozas Ramanauskas ◽  
Algimantas Vasylius
Keyword(s):  
Thermal Conductivity ◽  
Thermal Properties ◽  
Thermal Characteristics ◽  
Insulation Layer ◽  
Geometrical Properties ◽  
Thermal Transmittance ◽  
Energy Efficient Buildings ◽  
Thermal Bridge ◽  
Thermal Bridges ◽  
Bearing Layer

During the design of energy-efficient buildings with a ventilated fa?ade systems, the evaluation of point thermal transmittance is complicated. It requires additional theoretical knowledge, special software and skills to use it. Because of that, point thermal transmittance is often ignored in practice. The dependence of point thermal transmittance, which is appearing because of aluminum fixing elements used in the insulated wall with ventilated fa?ade system, from the thermal and geometrical properties of construction layers are analyzed in this paper. Research has shown, that thermal properties of the supporting wall, where fixing element is located, had the biggest influence on the point thermal transmittance. When thermal conductivity of the supporting wall was increasing, as well as a thickness of the insulation layer, a value of thermal bridge was increasing in a non-linear way. For this reason, the thermal transmittance coefficient of all construction could increase up to 35%. When the thickness of the supporting wall and thermal conductivity of the insulation layer was increased, the value of point thermal bridge was decreasing. The tests revealed strong dependency of the point thermal bridge on the thermal conductivity of bearing layer material and the thickness of the bearing layer of wall. For this reason, thermal bridges should receive greater consideration. It is not enough to use the diagrams of typical fasteners that very often do not take into account the exact thickness and thermal characteristics of materials

scholarly journals THE INFLUENCE OF LINEAR THERMAL TRANSMITTANCE OF THERMAL BRIDGES ON THE ENERGY PERFORMANCE CLASS OF BUILDINGS – SIMPLIFIED METHOD

2016 ◽  
Vol 1 (14) ◽  
Author(s):  
Danilo Vunjak ◽  
Arpad Čeh ◽  
Neđo Đurić ◽  
Golub Karaman ◽  
Ivan Hegediš
Keyword(s):  
Energy Consumption ◽  
Significant Influence ◽  
Energy Performance ◽  
Heat Losses ◽  
Thermal Transmittance ◽  
Simplified Method ◽  
Thermal Bridges

Thermal bridges have significant influence at calculation of the energy performance classes ofbuildings. This especially applies to countries where energy performance classes of buildings aredetermined based only on energy consumption for heating (such as Serbia, Bosnia and Hercegovina,Croatia...). Significant differences arise in determining the heat losses due to thermal bridges.Differences that can occur by using simplified methods depending on national recommendations ofdifferent countries are shown in this article.

scholarly journals An Analysis of Repeating Thermal Bridges from Timber Frame Fraction in Closed Panel Timber Frame Walls: A Case Study from Wales, UK

Energies ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 1211
Author(s):  
Francesco Zaccaro ◽  
John Richard Littlewood ◽  
Carolyn Hayles
Keyword(s):  
Thermal Performance ◽  
Energy Use ◽  
Design Stage ◽  
Performance Gap ◽  
Thermal Transmittance ◽  
Timber Frame ◽  
Operational Energy ◽  
Thermal Bridges ◽  
Detrimental Impact

Calculating Repeating Thermal Bridges (RTBs) for Timber Frame (TF) closed panels that could occur in Offsite Manufactured (OSM) Modern Methods of Construction (MMC), such as exterior walls for nearly-to-zero operational energy dwellings to be constructed in Wales, United Kingdom (UK) is discussed in this paper. Detailed calculations for linear RTBs due to the TF components are often neglected when evaluating thermal transmittance (known as U-values hereafter). The use of standard TF fractions does not allow the designer to perceive their detrimental impact on RTBs and consequent U-values for exterior walls. With the increase of the thermal performance of exterior walls and as such lower U-values due to ever-tightening Building Regulations, specifically related to the energy use and carbon emissions from the space heating of dwellings, then the impacts of RTBs requires more investigation. By not calculating the potential of linear RTB at the design stage could lead to a performance gap where assumed U-values for exterior walls differ from manufacture to onsite. A TF detail from the Welsh manufacture has been chosen as a case study, to develop and apply a methodology using manufacturing drawings to evaluate TF fraction and their effect on the thermal performance.

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