scholarly journals Experimental Evidence on the Thermal Performance of Opaque Surfaces in Mediterranean Climate

2013 ◽  
Vol 860-863 ◽  
pp. 1227-1231 ◽  
Author(s):  
Vincenzo Franzitta ◽  
Angelo Milone ◽  
Daniele Milone ◽  
Salvatore Pitruzzella ◽  
Marco Trapanese ◽  
...  

The thermal insulation of buildings, intended as wrap feature which determines the dispersion of heat, the reference parameter is necessary to contain the thermal losses during the winter season. The transmittance of the opaque components, used as an indicator of the energy quality of a casing, together with the overall coefficient of dispersion, represents a proper descriptor of the behavior during the heating season. However, if a strong insulation in winter conditions brings only positive effects, the same cannot be said for the summer conditions. A high value of the insulation in the casing is convenient only when the gains free, either in the form of solar contribution that of endogenous heat, are controlled and restricted. From the national transposition of the 2002/91/CE legislation up to the 2010/31/EU on the energy performance of buildings, performance values are set very restrictive transmittance of opaque surfaces that both of those transparent to the new buildings. The same does not happen for the thermophysical characteristics able to implement strategies for the control of solar radiation during the summer period, the fluctuations in external temperatures during the summer period. This article shows some experimental evidence of the effects on transmission rate and density of the opaque elements of the buildings carried out on a case study of a representative building of climate-Mediterranean summer: The study verify the results produced by increased insulation of the building envelope on energy performance of buildings during the summer through indicators such as temperature and energy consumption to maintain the same constant with respect to the prescribed values.

2015 ◽  
Vol 789-790 ◽  
pp. 1181-1184
Author(s):  
Michal Kraus ◽  
Kateřina Kubeková ◽  
Darja Kubečková

The main objective of the paper is to confirm or exclude a statistically significant impact of airtightness on the energy performance of buildings. Energy performance of buildings is characterized by a specific energy demand for heating and specific total primary energy. Airtightness is one of the key factors of energy efficient buildings. The quality of airtight building envelope except for low energy consumption also minimizes the risk of damage to the structure associated with the spread of the heat and water vapor in the structure.


2020 ◽  
Vol 172 ◽  
pp. 22004
Author(s):  
Jade Deltour ◽  
Nicolas Heijmans ◽  
Karel De Sloover

In order to achieve carbon neutrality in the building field as expected by the Energy Performance of Buildings Directive, it is important to not only be able to calculate energy performance during design but also to be able to measure the actual energy performance of buildings during occupancy. However, there is currently no approved methodology for assessing the energy performance of the building envelope of an occupied building independently of its occupants, its systems and the climate. We applied a mathematical method to determine the heat loss coefficient (HLC) of the building envelope, from data collected in occupied buildings. The paper describes the in-situ measurement protocol and the mathematical models that contributes to address this challenge. Our methodology is demonstrated on a new semi-detached house, more insulated than the regulatory level, located in Brussels from a full year of monitoring data. For this case study, the results are promising. Indeed, some mathematical models show results of the same range value for the occupied insitu HLC and the reference HLC, obtained from in-situ measurements but without occupancy. However, more case studies should be evaluated, in order to validate the methodology.


2014 ◽  
Vol 1056 ◽  
pp. 128-130
Author(s):  
Fu Yun Yang

Doors and windows of the building is an important part of the building envelope. AS the transparent and open envelope of the building, doors and windowsare the weakest part in the winter and summer heat preservation. It directly affects the energy performance of buildings. Therefore, do a good job of building doors and windows energy saving is an important way to optimize the indoor environment and realize energy saving.


Author(s):  
Anna Ostańska

The proposed interdisciplinary method of identifying defects in the building envelope insulation enables the user to quickly assess the scale of heat loss problems in occupied buildings. The method rests upon the quantitative analysis of macroscopic infrared images of the buildings. The method was applied in practice to assess effects of thermal upgrade project in Dźbów housing estate in Częstochowa, a city located in southern Poland. The results confirmed the applicability of the method to monitoring energy performance of buildings in use without intervention into the building’s fabric and without disturbing the occupants.


Energies ◽  
2020 ◽  
Vol 13 (10) ◽  
pp. 2469
Author(s):  
Evi Lambie ◽  
Dirk Saelens

Since households are one of the most energy-intensive sectors in Europe, retrofit of dwellings is promoted to increase energy efficiency. Recent research, however, shows that the energy performance after retrofit does not always meet the target values, which can be caused by amongst other things, a deviating building envelope performance. This paper compares the theoretical and measured building envelope performance for a real-life case study in post-retrofit state, in order to illustrate the limitations of calculation methods and characterization models. First, the performance is evaluated on building scale by verifying the correspondence between the default theoretical heat loss coefficient (HLC) and the measured HLC, which was determined by following the guidelines formulated within IEA EBC Annex 58 and Annex 71. In order to illustrate the limitations of the standard calculation method in real-life conditions, the theoretical variability of the HLC is evaluated, generated by variating infiltration heat losses and heat exchange with neighboring dwellings. Second, the performance is investigated on a component scale by assessing the theoretical and measured thermal resistances, identified from heat flux tests. Additionally, nonhomogeneous assembled components and air leaks are simulated to verify probable causes for the locally varying measured values and to illustrate the limitations of calculations and characterization methods. The results illustrate the limitations of the calculation methods by the assessment of the strong variability of the theoretical HLC, depending on assumptions regarding infiltration and heat exchange with neighboring dwellings. In addition, component simulations indicated that deficiencies on a component scale could be caused by a nonhomogeneous assembly and air cavity flows of the component. Moreover, a detailed assessment of an unreliable thermal resistance illustrates the limitations of the used characterization method. Finally, a contrast was found between the quite good performance on building scale (15% deviation between the theoretical and measured HLC) and poor performance on a component scale (only one out of nine monitored components met their theoretical target values), which illustrates the complexity of the building envelope performance.


2014 ◽  
Vol 899 ◽  
pp. 143-146 ◽  
Author(s):  
Veronika Sipkova ◽  
Jiri Labudek ◽  
Otakar Galas

The team of Building environment in VŠB-Technical university of Ostrava works intensively on options in long-term accumulation of heat in underground storages. The new concept follows the Directive of the European Parliament and of the Council 2010/31/EU on the energy performance of buildings [1]. The Directive requires that energy should be extensively covered of renewable sources produced at or in the vicinity of building, where it will be consumed. The aim of the research is create thermal energy storage with model structure for complex of family house. For the storage will be used recycled materials especially recycled concrete. This system will be heat source in winter period and heat consumer in summer period.


2014 ◽  
Vol 564 ◽  
pp. 315-320 ◽  
Author(s):  
Maatouk Khoukhi ◽  
Mahmoud Tahat

The impact of the thermal conductivity (k-value) change of polystyrene insulation material in building envelope due to changes in temperature on the thermal and energy performance of a typical residential building under hot climate is investigated. Indeed, the thermal and energy performance of buildings depends on the thermal characteristics of the building envelope, and particularly on the thermal resistance of the insulation material used. The thermal insulation material which is determined by its thermal conductivity, which describes the ability of heat to flow cross the material in presence of a gradient of temperature, is the main key to assess the performance of the thermal insulation material. When performing the energy analysis or calculating the cooling load for buildings, we use published values of thermal conductivity of insulation materials, which are normally evaluated at 24°C according to the ASTM standards. In reality, thermal insulation in building is exposed to significant and continuous temperature variations, due essentially to the change of outdoor air temperature and solar radiation. Many types of insulation materials are produced and used in Oman, but not enough information is available to evaluate their performance under the prevailing climatic condition. The main objective of this study is to investigate the relationship between the temperature and thermal conductivity of various densities of polystyrene, which is widely used as building insulation material in Oman. Moreover, the impact of thermal conductivity variation with temperature on the envelope-induced cooling load for a simple building model is discussed. This work will serve as a platform to investigate the effect of the operating temperature on thermal conductivity of other building material insulations, and leads to more accurate assessment of the thermal and energy performance of buildings in Oman.


2019 ◽  
Vol 12 (1) ◽  
pp. 120
Author(s):  
Eunsil Lee

Despite the rapid growth in the number of LEED-certified homes, little data is currently available about the actual effects of LEED-certified affordable homes. The purpose of present study is to conduct a comprehensive performance evaluation for LEED-certified Habitat for Humanity residences in terms of (1) energy efficiency, (2) indoor environmental quality, (3) health impact, (4) residential satisfaction, (5) quality of life, and (6) environmental attitudes and behaviors. A case study was conducted with 15 households living in LEED-certified Habitat for Humanity homes in Kent County, Michigan using observation, in-depth interviews, and surveys. Findings revealed overall housing satisfaction was very high although some residents indicated lower satisfaction with their neighborhood. Most of case study homes had 30-50% lower electricity and natural gas bills. Most participants were satisfied with indoor environmental quality (IEQ) including thermal comfort, indoor air quality, amount daylight, quality of artificial lighting, and acoustical condition. Most participants agreed that since moving into their current homes they have experienced improved family relationships, better health conditions, more positive attitudes, and better performance of their children. The major findings of this case study support the positive effects of LEED-certified low-income homes on residents’ behavioral, social, and psychological aspects of well-being.


2016 ◽  
Vol 2016 ◽  
pp. 1-180
Author(s):  
Katerina Petrushevska

AIM: This research examines the important issue of energy efficient improvements to the existing building stock through building envelope upgrade. To facilitate this, the energy performance characteristics of the existing building stock were identified with a view to establishing an existing building stock type, where building envelope upgrades can contribute to a higher level of energy efficiency improvements. The literature review along with the selected building precedents was used to establish the best current practice for building envelope upgrades.MATERIAL AND METHODS: Established building precedents and identified best practice for building envelope upgrade, a high rise block of flats was identified and used as a case study, with the current and predicted, following building envelope upgrade, energy performance of the building calculated. This has allowed us to identify the possible energy efficiency improvements for this type of building following the building envelope upgrade. RESULTS: In the projected case, the building with energy class - "D" become class "B". In addition, increased quality of the living room in the attic was enabled. It was possible to obtain a decrease of the heating energy from 130.76 kWh/m²a to 37.73 kWh/m²a or to jump in the class "B" of energetic passport.CONCLUSION: This research contributes to the local implementation of the global agenda for sustainable development, design and construction, and it demonstrates the possible way and level of energy efficiency improvements to the least efficient building stock through existing building envelope upgrade.


2021 ◽  
Vol 2069 (1) ◽  
pp. 012006
Author(s):  
A Kabore ◽  
W Maref ◽  
C O Plamondon

Abstract This document is a case study of hemp-based materials integrated into the building envelope for African and North American’s applications. The objective is to evaluate the energy performance of hemp concrete for construction in Montreal, Canada, where heating predominates and in Dori, Burkina Faso, where air conditioning predominates. The effect of thermal and hygrothermal comfort of hemp concrete, glass wool, cement block and compressed earth brick walls were simulated to quantify the benefits on overheating during the hottest months for the city of Dori and the risk of mould growth in the walls of the building in winter for the city of Montreal.


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