Thermal bridges in building construction. Linear thermal transmittance. Simplified methods and default values

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.

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Influence of Exact Values of Increase of Thermal Transmittance because of Thermal Bridges on Energy Need for Heating of Panel Residential Houses in Original State and after Renewal

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.855.108 ◽

2013 ◽

Vol 855 ◽

pp. 108-111

Author(s):

Rastislav Menďan

Keyword(s):

Thermal Insulation ◽

Specific Energy ◽

Housing Development ◽

Mass Housing ◽

Original State ◽

Thermal Transmittance ◽

Thermal Bridges

The paper presents calculated values of increase of thermal transmittance because of thermal bridges (ΔU value) of panel residential houses of mass housing development. These values are compared with general values, which are given in the standard STN 73 0540-2 and afterwards a specific energy need for heating considering exact ΔU values but also general ΔU values was calculated as well. The residential houses were evaluated in original state and in state after the renewal by adding thermal insulation on walls, roof and after replacement of windows.

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Analysis of the Relationship of the Improvement of Façades and Thermal Bridges of Spanish Building Stock with the Mitigation of Its Energy and Environmental Impact

Energies ◽

10.3390/en13174499 ◽

2020 ◽

Vol 13 (17) ◽

pp. 4499 ◽

Cited By ~ 1

Author(s):

David Bienvenido-Huertas

Keyword(s):

Energy Conservation ◽

Carbon Dioxide Emissions ◽

Low Carbon ◽

The European Union ◽

Building Stock ◽

Low Carbon Economy ◽

Thermal Transmittance ◽

Conservation Measures ◽

Thermal Bridges ◽

Energy Conservation Measures

The energy improvement of building stock is essential to achieve a low-carbon economy. The improvement of façades is among the most common measures to reduce energy consumption. However, the effect of thermal bridges is undervalued in most cases. This study assesses the effect of improving building façades and thermal bridges. For this purpose, a case study is assessed for all climate zones in Spain, both in current and future scenarios, considering operational patterns from the COVID-19 pandemic. The study shows that the application of energy conservation measures focusing on reducing the thermal transmittance of façades and the linear thermal transmittance of thermal bridges has a more significant energy and environmental effect than other, more economical energy conservation measures that do not improve the effect of thermal bridges. Likewise, the application of energy conservation measures to improve façades can reduce carbon dioxide emissions but are far from achieving the 90% reduction set by the European Union by 2050. Consequently, these measures should be combined with other measures.

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