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Calculation of thermal bridges in (Nordic) building envelopes - Risk of performance failure due to inconsistent use of methodology

Berggren, Björn LU and Wall, Maria LU (2013) In Energy and Buildings 65. p.331-339
Abstract
Reduction of energy use in buildings is an important measure to achieve climate change mitigation. It is essential to minimize heat losses when designing and building energy efficient buildings. For an energy-efficient building in a cold climate, a large part of the space heating demand is caused by transmission losses through the building envelope. Therefore, calculations of these must be carried out in a correct way to ensure a properly sized heating system and a good indoor climate. There is today a risk of misunderstanding and inconsistent use of methodology when transmission heat transfer is calculated. To investigate the state of knowledge among Swedish consultants a survey was conducted regarding thermal bridges and calculations of... (More)
Reduction of energy use in buildings is an important measure to achieve climate change mitigation. It is essential to minimize heat losses when designing and building energy efficient buildings. For an energy-efficient building in a cold climate, a large part of the space heating demand is caused by transmission losses through the building envelope. Therefore, calculations of these must be carried out in a correct way to ensure a properly sized heating system and a good indoor climate. There is today a risk of misunderstanding and inconsistent use of methodology when transmission heat transfer is calculated. To investigate the state of knowledge among Swedish consultants a survey was conducted regarding thermal bridges and calculations of transmission heat transfer. Furthermore, the impact of thermal bridges was studied by comparative calculations for a case study building with different building systems and different amounts of insulation. The study shows that the relevant standards and the building code in Sweden are interpreted in many different ways regarding calculation of transmission heat transfer and energy performance. There is a lack of understanding regarding the impact of different measuring methods on thermal bridges. When more insulation is used the relative impact of thermal bridges increases. It is therefore not suitable to use a single predefined percentage factor, increasing the transmission heat transfer through building elements, to account for the effect of thermal bridges. If values for normalized thermal bridges are to be used, they need to be differentiated by building system and different amounts of insulation (C) 2013 Elsevier B.V. All rights reserved. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Thermal bridges, EN ISO 13789, EN ISO 10211, Transmission heat transfer, Dimensions
in
Energy and Buildings
volume
65
pages
331 - 339
publisher
Elsevier
external identifiers
  • wos:000324449800035
  • scopus:84880306577
ISSN
1872-6178
DOI
10.1016/j.enbuild.2013.06.021
language
English
LU publication?
yes
id
8c77646d-3536-4f42-a0b2-eff64afb45f9 (old id 4095871)
date added to LUP
2013-10-22 14:09:01
date last changed
2019-01-06 03:33:59
@article{8c77646d-3536-4f42-a0b2-eff64afb45f9,
  abstract     = {Reduction of energy use in buildings is an important measure to achieve climate change mitigation. It is essential to minimize heat losses when designing and building energy efficient buildings. For an energy-efficient building in a cold climate, a large part of the space heating demand is caused by transmission losses through the building envelope. Therefore, calculations of these must be carried out in a correct way to ensure a properly sized heating system and a good indoor climate. There is today a risk of misunderstanding and inconsistent use of methodology when transmission heat transfer is calculated. To investigate the state of knowledge among Swedish consultants a survey was conducted regarding thermal bridges and calculations of transmission heat transfer. Furthermore, the impact of thermal bridges was studied by comparative calculations for a case study building with different building systems and different amounts of insulation. The study shows that the relevant standards and the building code in Sweden are interpreted in many different ways regarding calculation of transmission heat transfer and energy performance. There is a lack of understanding regarding the impact of different measuring methods on thermal bridges. When more insulation is used the relative impact of thermal bridges increases. It is therefore not suitable to use a single predefined percentage factor, increasing the transmission heat transfer through building elements, to account for the effect of thermal bridges. If values for normalized thermal bridges are to be used, they need to be differentiated by building system and different amounts of insulation (C) 2013 Elsevier B.V. All rights reserved.},
  author       = {Berggren, Björn and Wall, Maria},
  issn         = {1872-6178},
  keyword      = {Thermal bridges,EN ISO 13789,EN ISO 10211,Transmission heat transfer,Dimensions},
  language     = {eng},
  pages        = {331--339},
  publisher    = {Elsevier},
  series       = {Energy and Buildings},
  title        = {Calculation of thermal bridges in (Nordic) building envelopes - Risk of performance failure due to inconsistent use of methodology},
  url          = {http://dx.doi.org/10.1016/j.enbuild.2013.06.021},
  volume       = {65},
  year         = {2013},
}