scholarly journals Dependence of measured specific air leakage rate (qE50) on envelope pressure differences and measurement position: a case study in an apartment building in winter conditions

2021 ◽  
Vol 2069 (1) ◽  
pp. 012229
Author(s):  
P Klõšeiko ◽  
E Arumägi ◽  
J Hallik ◽  
T Kalamees
Keyword(s):  
Residential Building ◽  
Energy Performance ◽  
Building Envelope ◽  
Air Leakage ◽  
Apartment Building ◽  
Measurement Results ◽  
Air Leakage Rate ◽  
Random Nature ◽  
Airtightness Measurement

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.

scholarly journals Identification of the Building Envelope Performance of a Residential Building: A Case Study

Energies ◽  
2020 ◽  
Vol 13 (10) ◽  
pp. 2469
Author(s):  
Evi Lambie ◽  
Dirk Saelens
Keyword(s):  
Heat Exchange ◽  
Real Life ◽  
Residential Building ◽  
Poor Performance ◽  
Energy Performance ◽  
Building Envelope ◽  
Calculation Methods ◽  
Characterization Methods ◽  
Target Values

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.

scholarly journals Methodology for the Study of the Envelope Airtightness of Residential Buildings in Spain: A Case Study

Energies ◽  
2018 ◽  
Vol 11 (4) ◽  
pp. 704 ◽  
Author(s):  
Jesús Feijó-Muñoz ◽  
Irene Poza-Casado ◽  
Roberto Alonso González-Lezcano ◽  
Cristina Pardal ◽  
Víctor Echarri ◽  
...  
Keyword(s):  
Housing Stock ◽  
Residential Buildings ◽  
Energy Performance ◽  
Air Leakage ◽  
Mediterranean Countries ◽  
Relevant Variables ◽  
Ventilation Rates ◽  
Air Leakage Rate

Air leakage and its impact on the energy performance of dwellings has been broadly studied in countries with cold climates in Europe, US, and Canada. However, there is a lack of knowledge in this field in Mediterranean countries. Current Spanish building regulations establish ventilation rates based on ideal airtight envelopes, causing problems of over-ventilation and substantial energy losses. The aim of this paper is to develop a methodology that allows the characterization of the envelope of the housing stock in Spain in order to adjust ventilation rates taking into consideration air leakage. A methodology that is easily applicable to other countries that consider studying the airtightness of the envelope and its energetic behaviour improvement is proposed. A statistical sampling method has been established to determine the dwellings to be tested, considering relevant variables concerning airtightness: climate zone, year of construction, and typology. The air leakage rate is determined using a standardized building pressurization technique according to European Standard EN 13829. A representative case study has been presented as an example of the implementation of the designed methodology and results are compared to preliminary values obtained from the database.

scholarly journals Energy Performance of a High-Rise Residential Building Using Fibre-Reinforced Structural Lightweight Aggregate Concrete

2020 ◽  
Vol 10 (13) ◽  
pp. 4489
Author(s):  
Zakaria Che Muda ◽  
Payam Shafigh ◽  
Norhayati Binti Mahyuddin ◽  
Samad M.E. Sepasgozar ◽  
Salmia Beddu ◽  
...  
Keyword(s):  
Residential Building ◽  
Green Building ◽  
Lightweight Aggregate ◽  
Energy Performance ◽  
Building Envelope ◽  
Lightweight Aggregate Concrete ◽  
Aggregate Concrete ◽  
High Rise ◽  
Passive Design ◽  
Envelope Material

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.

scholarly journals Overview of large building testing in Baltic countries

2020 ◽  
Vol 172 ◽  
pp. 05007
Author(s):  
Andrejs Nitijevskis ◽  
Vladislavs Keviss
Keyword(s):  
Quality Control ◽  
Pressure Difference ◽  
Leakage Rate ◽  
Air Leakage ◽  
Baltic Countries ◽  
Measurement Results ◽  
The Mean ◽  
Mandatory Testing ◽  
Air Leakage Rate ◽  
Large Building

The objectives of this paper are to review measurements of airtightness of 2 large building groups – middle size shops, and warehouses/distribution centres. The mean air leakage rate at 50 Pa pressure difference q50 was 1.04 m3/m2h and 1.35 m3/m2h for shops and warehouses respectively. Analysis of measurement results is valuable because it allows to make a conclusion about compliance of national and corporative construction airtightness norms with actual air barrier condition on a comissioning stage. In the concluding part of the study there are suggested ways to improve air barrier such as review of construction norms, implementation of a mandatory testing and quality control of a measurement.

scholarly journals Redefining cost-optimal nZEB levels for new residential buildings

2019 ◽  
Vol 111 ◽  
pp. 03035 ◽  
Author(s):  
Raimo Simson ◽  
Endrik Arumägi ◽  
Kalle Kuusk ◽  
Jarek Kurnitski
Keyword(s):  
Energy Use ◽  
Net Present Value ◽  
Residential Buildings ◽  
Energy Performance ◽  
Optimal Level ◽  
Building Envelope ◽  
Simulation Software ◽  
The European Union ◽  
Apartment Building ◽  
Detached House

In the member states of the European Union (EU), nearly-Zero Energy Buildings (nZEB) are becoming mandatory building practice in 2021. It is stated, that nZEB should be cost-optimal and the energy performance levels should be re-defined after every five years. We conducted cost-optimality analyses for two detached houses, one terraced house and one apartment building in Estonia. The analysis consisted on actual construction cost data collection based on bids of variable solutions for building envelope, air tightness, windows, heat supply systems and local renewable energy production options. For energy performance analysis we used dynamic simulation software IDA-ICE. To assess cost-effectiveness, we used Net Present Value (NPV) calculations with the assessment period of 30 years. The results for cost-optimal energy performance level for detached house with heated space of ~100 m2 was 79 kWh/(m2 a), for the larger house (~200 m2) 87 kWh/(m2 a), for terraced house with heated space of ~600 m2 71 kWh/(m2 a) and for the apartment building 103 kWh/(m2 a) of primary energy including all energy use with domestic appliances. Thus, the decrease in cost-optimal level in a five-year period was ~60% for the detached house and ~40% for the apartment building, corresponding to a shift in two EPC classes.

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 Usability of the EPC Tools for the Profitability Calculation of a Retrofitting in a Residential Building

2018 ◽  
Vol 10 (9) ◽  
pp. 3159 ◽  
Author(s):  
Alex Gonzalez Caceres ◽  
Muriel Diaz
Keyword(s):  
Life Cycle Cost ◽  
Residential Building ◽  
Energy Performance ◽  
Energy Regulation ◽  
The European Union ◽  
Financial Assessment ◽  
Efficiency Assessment ◽  
Consumption Energy ◽  
Oil Crisis

After the oil crisis in the 70s energy regulation codes were implemented, but a great portion of existing dwellings have not been retrofitted to current requirements. To face this issue several actions were taken in the European Union (EU), among these, the implementation of Energy Performance Certificates (EPC), which include a Recommendation List of Measures (RLMs) to retrofit buildings. Some concerns exist about the lack of confidence on these recommendations. The main objective of this study is to analyze the usefulness of the EPC, answering if it is possible to deliver a realistic financial assessment about renovation strategies using these tools. The study is based on three indicators: Consumption, energy saving variations and profitability. The study is based on a renovation project case study, where simulations and Life Cycle Cost Assessment (LCCA) were performed, in order to identify the different results that EPC’s and an energy efficiency assessment could lead to. The results show important differences in all the concepts evaluated.

scholarly journals Energy flexibility in Mediterranean buildings: a case-study in Sicily

2020 ◽  
Vol 197 ◽  
pp. 02002
Author(s):  
Ilaria Marotta ◽  
Francesco Guarino ◽  
Maurizio Cellura ◽  
Sonia Longo
Keyword(s):  
Residential Building ◽  
Energy Performance ◽  
Global Scale ◽  
Single Family ◽  
Flexible Control ◽  
Emission Signal ◽  
Reduce Emissions ◽  
Definition Of ◽  
Family House

Since the building sector is responsible for 40% of the world’s electricity demand, it is essential to act on it in order to reduce emissions of climate change gases on a global scale, as expressed also in the latest directive on the energy performance of buildings. A design approach that focuses on the energy flexibility of buildings can contribute to the improvement of its energy-environmental performances. In this context, the objective of the study is the analysis of the energy performance of a residential building in Sicily and the definition of strategies aimed at increasing its energy flexibility. In particular, the case study is a 631 m2 single-family house, modeled and simulated in TRNSYS environment. The approach involves the development of scenarios to reduce operating costs and CO2 emissions during the use phase of the building. Rule Based Control algorithms are implemented. The flexible control reacts to a price or emission signal, by modulating the heating set-point accordingly. The results highlighted significant increases in energy flexibility. The economic algorithm achieves savings of 21.46%, accompanied by a 15% reduction in emissions. The environmental algorithm allows to reduce CO2 emissions by about 30%. The economic impact is positive, with a 17.58% reduction in costs.

scholarly journals Energy Efficient Improvements of Existing Buildings through Building Envelope Upgrade Case Study of High Rise Block of Flats on 76, Boulevard Partizanski Odredi in Karpos IV, Skopje

2016 ◽  
Vol 2016 ◽  
pp. 1-180
Author(s):  
Katerina Petrushevska
Keyword(s):  
Energy Efficiency ◽  
Energy Efficient ◽  
Energy Performance ◽  
Building Envelope ◽  
Living Room ◽  
Building Stock ◽  
Existing Building ◽  
High Rise ◽  
Class B

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.

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