Modeling the performance of residential building envelope: The role of sustainable energy performance indicators

2011 ◽  
Vol 43 (9) ◽  
pp. 2108-2117 ◽  
Author(s):  
Abraham Mwasha ◽  
Rupert G. Williams ◽  
Joseph Iwaro
2020 ◽  
Vol 10 (13) ◽  
pp. 4489
Author(s):  
Zakaria Che Muda ◽  
Payam Shafigh ◽  
Norhayati Binti Mahyuddin ◽  
Samad M.E. Sepasgozar ◽  
Salmia Beddu ◽  
...  

The increasing need for eco-friendly green building and creative passive design technology in response to climatic change and global warming issues will continue. However, the need to preserve and sustain the natural environment is also crucial. A building envelope plays a pivotal role in areas where the greatest heat and energy loss often occur. Investment for the passive design aspect of building envelopes is essential to address CO 2 emission. This research aims to explore the suitability of using integral-monolithic structural insulation fibre-reinforced lightweight aggregate concrete (LWAC) without additional insulation as a building envelope material in a high-rise residential building in the different climatic zones of the world. Polypropylene and steel fibres in different dosages were used in a structural grade expanded clay lightweight aggregate concrete. Physical and thermal properties of fibre reinforced structural LWAC, normal weight concrete (NWC) and bricks were measured in the lab. The Autodesk@Revit-GBS simulation program was implemented to simulate the energy consumption of a 29-storey residential building with shear wall structural system using the proposed fibre-reinforced LWAC materials. Results showed that energy savings between 3.2% and 14.8% were incurred in buildings using the fibre-reinforced LWAC across various climatic regions as compared with traditional NWC and sand-cement brick and clay brick walls. In conclusion, fibre-reinforced LWAC in hot-humid tropical and temperate Mediterranean climates meet the certified Green Building Index (GBI) requirements of less than 150 kW∙h∙m−2. However, in extreme climatic conditions of sub-arctic and hot semi-arid desert climates, a thicker wall or additional insulation is required to meet the certified green building requirements. Hence, the energy-saving measure is influenced largely by the use of fibre-reinforced LWAC as a building envelope material rather than because of building orientation.


2019 ◽  
Vol 14 (2) ◽  
pp. 109-136
Author(s):  
Chaitali Basu ◽  
Virendra Kumar Paul ◽  
M.G. Matt Syal

The energy performance of an existing building is the amount of energy consumed to meet various needs associated with the standardized use of a building and is reflected in one or more indicators known as Building Energy Performance Indicators (EnPIs). These indicators are distributed amongst six main factors influencing energy consumption: climate, building envelope, building services and energy systems, building operation and maintenance, occupants' activities and behaviour, and indoor environmental quality. Any improvement made to either the existing structure or the physical and operational upgrade of a building system that enhances energy performance is considered an energy efficiency retrofit. The main goal of this research is to support the implementation of multifamily residential building energy retrofits through expert knowledge consensus on EnPIs for energy efficiency retrofit planning. The research methodology consists of a comprehensive literature review which has identified 35 EnPIs for assessing performance of existing residential buildings, followed by a ranking questionnaire survey of experts in the built-environment to arrive at a priority listing of indicators based on mean rank. This was followed by concordance analysis and measure of standard deviation. A total of 280 experts were contacted globally for the survey, and 106 completed responses were received resulting in a 37.85% response rate. The respondents were divided into two groups for analysis: academician/researchers and industry practitioners. The primary outcome of the research is a priority listing of EnPIs based on the quantitative data from the knowledge-base of experts from these two groups. It is the outcome of their perceptions of retrofitting factors and corresponding indicators. A retrofit strategy consists of five phases for retrofitting planning in which the second phase comprises an energy audit and performance assessment and diagnostics. This research substantiates the performance assessment process through the identification of EnPIs.


2019 ◽  
Vol 887 ◽  
pp. 164-171
Author(s):  
Marija Marković ◽  
Ulrich Pont ◽  
Ardeshir Mahdavi

Energy performance calculations are stipulated by law in most European countries. Thereby, different calculation schemes have been developed in the past years in different countries. The physical processes in buildings were simplified in terms of normative calculation routines in most of these schemes. A major idea behind these simplifications was to enable different stakeholders (practitioners, engineers, and architects) to issue energy certificates without being simulation experts. Moreover, the simplifications needed to be described thoroughly in corresponding guidelines to ensure and facilitate the comparability of the energy performance of different buildings. However, neither of these objectives can be considered to be fully met. Regarding the former, the normative calculation procedures increased in complexity in the past years, so that the issuing of energy certificates requires not only the stakeholder’s expertise but also a comprehensive knowledge of the standards that form the calculation method. Regarding the latter, recent research efforts revealed that many guidelines do not fully cover every aspect of the calculation procedures and the assumptions regarding required input data. Thus, the comparability of energy certificates has to be strongly questioned, as a number of relevant calculation parameters are dependent on the interpretation of the corresponding issuer.Given this background, alternative approaches to building performance evaluation would be of interest. Previous approaches by different researchers suggested so called prescriptive indicators, which can be derived by basic building data (for instance, geometry and thermal quality of the building envelope components). This contribution is based on this concept. In the framework of a master thesis, a number of prescriptive indicators were considered. These indicators were derived for a set of sample buildings. In a parallel effort, energy certificates (encompassing Key Performance Indicators KPIs) were calculated for the sample buildings. It is clear that the prescriptive indicators cannot act as a 1:1 replacement for KPIs in terms of a numeric value. However, their usefulness can be expressed by the relation of the prescriptive indicator and the corresponding KPIs of a building. Thus, the results of the described calculation efforts were ranked. Subsequently, the lists of buildings ranked by the different indicators were compared in order to identify prescriptive indicators, which result in the same or at least similar ranking as the normative key performance indicators. Within this contribution, the suggested prescriptive indicators, the sample buildings, and the results of the analysis are presented and discussed.


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.


2021 ◽  
Vol 2069 (1) ◽  
pp. 012229
Author(s):  
P Klõšeiko ◽  
E Arumägi ◽  
J Hallik ◽  
T Kalamees

Abstract Airtightness of the building envelope has become an important component in achieving ever stricter energy performance levels. However, airtightness measurements using blower door method are dependent on choices made by the specialist conducting the tests. One being the assessment of baseline pressure difference inside the building and position of the measurement equipment. Ideally, the test will be conducted without wind and stack effect which could disturb the envelope pressure measurements. Unfortunately, such conditions seldom exist, especially in colder climates. This increases the appeal of conducting apartment-wise measurements over whole-building measurements as it is far easier to comply with the ISO 9972. However, the apartment-wise method has a relatively random nature due to small share of actual building envelope. This paper investigates the effect of using different measurement positions and pressure levels on the airtightness measurement results. A 5-storey 15m tall residential building was used as a case study and measured as a whole and in select apartments. The results show that the variation caused by different choices of pressure levels, measurement positions etc caused relatively low variations and whole-building measurement should be preferred even if not all baseline and pressure level requirements are not met.


2021 ◽  
pp. 174425912110064
Author(s):  
Amal Louanate ◽  
Rabie El Otmani ◽  
Khalid Kandoussi ◽  
M’Hamed Boutaous ◽  
Daya Abdelmajid

Phase change materials (PCMs) show a good capability in absorbing massive heat when undergoing phase change, which have great potential to be incorporated into building envelopes to enhance indoor thermal comfort by preventing heat penetration into buildings and reducing energy requirements. In this work, a deep analysis of PCM enhanced-walls model has been conducted in six representative climate regions of Morocco: El Jadida, Fez, Marrakesh, Ifrane, and Errachidia. More in detail, numerical simulations were carried out to assess the thermal behavior and energy performance of a residential building integrated with four different PCMs. The results showed that the effectiveness and selection of PCMs strongly depend on local weather where they are applied, characteristics of HVAC systems, PCM layer thickness, and position. Furthermore, with reference to each climate zone, the appropriate PCM leading to the lowest annual energy consumption was identified. The findings show that PCMs are particularly suitable for Mediterranean climates, which a promising annual energy saving of about 41% was obtained. While, the lowest value was recorded in Errachidia city reveals that the integration of PCM has little effect in desert climate zone. As for the other climates considered, values of about 28% to 31% were achieved in the studied house model.


2021 ◽  
Vol 899 (1) ◽  
pp. 012009
Author(s):  
A C Karanafti ◽  
T G Theodosiou

Abstract Improving the energy efficiency of residential buildings is of outmost importance for reducing their environmental footprint. Recent studies demonstrate that a highly insulated building envelope may burden the building’s performance during the cooling period, especially in regions with hot summers. In this study, the energy performance of a residential building in different Mediterranean regions (Jordan, Greece, Iraq, Egypt, Syria, Morocco, Cyprus, Saudi Arabia, Libya, and Spain) is investigated. Two thermal transmittance values are applied to the building shell, a scenario with a very low one and a scenario with a higher one, to examine under which conditions the cooling performance is improved. A dynamic insulation configuration is also implemented, and its operation is studied for the cooling period of each city. It is concluded that in Southern European and Northern African regions building envelopes with lower thermal resistances perform better, while in even Southern regions an increased thermal resistance may prevent the heat from entering the building more effectively. With the switching insulation system, a great reduction in the cooling demands was reported, which reached up to 50% in Spain, and it was shown that in the southern regions the configuration’s operation should be customized to the ambient conditions to optimize its performance.


Atmosphere ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 405
Author(s):  
Amy Huynh ◽  
Regina Dias Barkokebas ◽  
Mohamed Al-Hussein ◽  
Carlos Cruz-Noguez ◽  
Yuxiang Chen

Due to the energy and environmental impacts attributed to the operational phase of the building sector, efforts have been made to improve building energy performance through the implementation of restrictive energy requirements by regulatory bodies. In this context, the primary objective of this paper is to investigate and compare regulations that govern the building envelope energy performance of new residential buildings in cold-climate regions, primarily in Canada, Finland, Iceland, Norway, Sweden, China, and Russia. The aim is to identify similarities and dissimilarities among the energy regulations of these countries, as well as potentials for development of more effective building codes. This study verifies that the investigated energy requirements diverge considerably—for instance, the required thermal resistance per unit area of above-grade exterior walls in Sweden is almost two times that of a similar climate zone in Canada. Based on the comparisons and case analyses, recommendations for energy requirements pertinent to building envelope of new residential buildings in cold-climate regions are proposed.


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