scholarly journals Temperature correction factor simulation over the heating period

2018 ◽  
Vol 22 (Suppl. 4) ◽  
pp. 1083-1093
Author(s):  
Biljana Vucicevic ◽  
Marina Jovanovic ◽  
Valentina Turanjanin ◽  
Vukman Bakic ◽  
Dusan Radivojevic

New Regulations on energy efficiency in buildings in the Republic of Serbia legislate values for the temperature correction factor used to calculate the heat flux to the outdoor environment through construction elements of a certain type. The temperature correction factor is used to correct errors caused by calculation of heat losses based on the design outdoor and indoor temperature difference of building elements adjacent to unheated spaces which are in direct contact with the ground or external environment. Since the temperature correction factor directly influences the calculation of total heat losses and total annual energy demand, it is recommended that the temperature correction factor be determined on the basis of measured values of outdoor and indoor air temperature, or, on the basis of the values obtained by the simulation. This paper presents the results of measurements in the High School of Design, Textile and Management in Belgrade in order to assess energy efficiency and the energy performance of buildings. Data obtained on the basis of measurements, such as indoor and outdoor temperatures, are used for the calculation of the heat transfer coefficient for the building envelope elements as well as to calculate a temperature correction factor for the unheated attic space of the building. This paper also offers a dynamic simulation of the multi-zones building in the TRNSYS environment. The aim was to compare temperature correction factor values obtained from measured temperature values, with those calculated from standard, taken from the Regulation table and produced by simulation.

Heritage ◽  
2021 ◽  
Vol 4 (4) ◽  
pp. 3919-3937
Author(s):  
Essam Elnagar ◽  
Simran Munde ◽  
Vincent Lemort

One pavilion was selected for deep retrofitting from the Otto Wagner area situated in the west of Vienna. The retrofitting process involves sustainable and energy-efficient construction to improve the energy performance and energy production potential of the building while preserving the cultural heritage and significance. This four-story pavilion was re-designed according to the proposed regulations of a net positive energy university building to become a student residence. Architectural, building envelope, and engineering interventions along with various changes were simulated through the Sefaira tool in the SketchUp model. These included: optimization of the U-values of the roof, walls, and floor; the addition of different layers of sustainable energy-efficient insulation materials to decrease the overall energy demand. The specific energy demands for heating, cooling, and lighting were decreased in the proposed model to reduce the total energy use intensity from 248.9 kWh/(m2 year) to 54.3 kWh/(m2 year) resulting in a 78.2% reduction. The main goal of this study is to try and achieve a net positive energy status building as part of the Otto Wagner area by improving the building envelope and integrating renewable energies. A total of 22.5% of the annual energy consumption was generated by the designed PV system. The selected building achieved the passive house standards in Austria by optimizing the energy performance with the proposed energy efficiency measures.


2019 ◽  
Vol 111 ◽  
pp. 03052 ◽  
Author(s):  
Mohammed Khalaf ◽  
Touraj Ashrafian ◽  
Cem Demirci

The energy conversations methods and techniques take a significant role in the energy performance of the buildings. Façade and shading systems are in continuous development, and recent studies are showing the importance of implementation of such systems to reduce energy consumption and enhance the effectiveness of the building performance. School buildings are mostly being used during daytime, hence, require active use of sunlight. A measure that is taken on a school building envelope can prevent overheating and overcooling and reduce the heating and cooling energy consumption but at the same time can increase the lighting energy consumption vice versa. Thus, it is necessary to optimise the energy required for climatisation of a building with lighting energy demand. The main aim of the paper is to provide analysis for façade and shading systems applied to a school building and study the effectiveness of it on energy consumption and conservation. The case study for this paper is a typical building project designed to be located in Istanbul, Turkey and has a traditional façade system which is clear double layer windows without any shading devices. The analyses of the energy efficiency of these systems will be presented. The different glazing types and shading systems alternatives will show the most efficient one to be used as some optimised alternatives for the systems. Findings indicate that proper glazing and shading systems can reduce the needed energy for heating and lightening and thus total energy consumption of a school building significantly.


2019 ◽  
Vol 887 ◽  
pp. 335-343
Author(s):  
Nazanin Moazzen ◽  
Mustafa Erkan Karaguler ◽  
Touraj Ashrafian

Energy efficiency has become a crucial part of human life, which has an adverse impact on the social and economic development of any country. In Turkey, it is a critical issue especially in the construction sector due to increase in the dependency on the fuel demands. The energy consumption, which is used during the life cycle of a building, is a huge amount affected by the energy demand for material and building construction, HVAC and lighting systems, maintenance, equipment, and demolition. In general, the Life Cycle Energy (LCE) needs of the building can be summarised as the operational and embodied energy together with the energy use for demolition and recycling processes.Besides, schools alone are responsible for about 15% of the total energy consumption of the commercial building sector. To reduce the energy use and CO2 emission, the operational and embodied energy of the buildings must be minimised. Overall, it seems that choosing proper architectural measures for the envelope and using low emitting material can be a logical step for reducing operational and embodied energy consumptions.This paper is concentrated on the operating and embodied energy consumptions resulting from the application of different architectural measures through the building envelope. It proposes an educational building with low CO2 emission and proper energy performance in Turkey. To illustrate the method of the approach, this contribution illustrates a case study, which was performed on a representative schoold building in Istanbul, Turkey. Energy used for HVAC and lighting in the operating phase and the energy used for the manufacture of the materials are the most significant parts of embodied energy in the LCE analyses. This case study building’s primary energy consumption was calculated with the help of dynamic simulation tools, EnergyPlus and DesignBuilder. Then, different architectural energy efficiency measures were applied to the envelope of the case study building. Then, the influence of proposed actions on LCE consumption and Life Cycle CO2 (LCCO2) emissions were assessed according to the Life Cycle Assessment (LCA) method.


2015 ◽  
Vol 19 (3) ◽  
pp. 845-856
Author(s):  
Aleksandar Rajcic ◽  
Ana Radivojevic ◽  
Martin Elezovic

As a side effect of the need for greater energy efficiency of buildings, there is a problem of decrease of the available interior space affected by the reduction in U-value of parts of thermal building envelope, i.e. an increase in thickness of insulating layer, which is especially present in unheated staircase. Having in mind that present methods of calculation of transmission heat losses through elements of thermal envelope include the adjustment factor which regulates designed temperature conditions if the temperature at the colder side of the element of the thermal envelope differs from that of the external environment, this paper strives to demonstrate that in the case of unheated staircases, this fixed value should be reconsidered and treated as a variable depending on the morphology, i.e. form, size and position of the staircase within the building. This problem has been analyzed on the example of Serbian housing stock and relevant national thermal regulations. Three morphological types of unheated staircases have been distinguished within which three models have been defined and examined with respect to variations in number of floors and percentage of glazing. Average temperatures of staircase volume and temperature correction factors were calculated in following temperature modes: stationary that excluded solar gains and ventilation heat losses and gains, and dynamic with variations in air exchange rates and insolation conditions, expressing in all of the cases variations in calculated values of temperature correction factors in comparison to the prescribed fixed value.


2018 ◽  
Vol 880 ◽  
pp. 329-334
Author(s):  
Mădălina Xenia Călbureanu ◽  
Raluca Malciu ◽  
Calin Mihnea Calbureanu

This paper purpose is to provide recommendations after a thermal energy analysis and inspection of a hotel building and its related facilities, in order to increase energy efficiency saving primary resources, to ensure a healthy indoor climate for users, and last but not least to ensure a reduction of CO2 emissions in order to ensure an external environment with low pollutant emissions. All the carried out analysis has as main objective to consider a symbiosis between all the parameters involved (energy, indoor/outdoor environment, comfort), when a building (envelope and installations) is renovated, especially when excess in order to save energy tend to endanger the indoor climate. Non-invasive methods were used to inspect the building by using thermo-vision both for the building envelope and for inspection of existing installations. The building utilities bills were analyzed for a period of one year to highlight current energy performance. The given recommendations achieve the proposed goal and highlight the active role of building management, continuous monitoring of energy and utilities to assess and improve energy efficiency, and ultimately to minimize specific energy costs. The results of this study can be used successfully on a wide range of hotel buildings in Romania.


Energies ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3311
Author(s):  
Víctor Pérez-Andreu ◽  
Carolina Aparicio-Fernández ◽  
José-Luis Vivancos ◽  
Javier Cárcel-Carrasco

The number of buildings renovated following the introduction of European energy-efficiency policy represents a small number of buildings in Spain. So, the main Spanish building stock needs an urgent energy renovation. Using passive strategies is essential, and thermal characterization and predictive tests of the energy-efficiency improvements achieving acceptable levels of comfort for their users are urgently necessary. This study analyzes the energy performance and thermal comfort of the users in a typical Mediterranean dwelling house. A transient simulation has been used to acquire the scope of Spanish standards for its energy rehabilitation, taking into account standard comfort conditions. The work is based on thermal monitoring of the building and a numerical validated model developed in TRNSYS. Energy demands for different models have been calculated considering different passive constructive measures combined with real wind site conditions and the behavior of users related to natural ventilation. This methodology has given us the necessary information to decide the best solution in relation to energy demand and facility of implementation. The thermal comfort for different models is not directly related to energy demand and has allowed checking when and where the measures need to be done.


2021 ◽  
Vol 13 (0) ◽  
pp. 1-6
Author(s):  
Rasa Džiugaitė-Tumėnienė ◽  
Domas Madeikis

The high share of global energy costs to create an indoor climate has been of increasing interest to the global community for several decades and is increasingly the focus of policy. This paper analyses the energy performance gap between actual energy consumption and energy demand obtained during the dynamic energy simulation and building certification. To identify the energy performance gap, an existing office of energy efficiency class B was selected as a case study. The simulation program IDA Indoor Climate and Energy was used to create a dynamic energy model, based on the designed documentation and the actual indoor climate parameters recorded by the building management system. The results of the case study showed that the accuracy and reliability of the results presented by the dynamic energy model of the building directly depend on the assumptions. The correct values of the internal heat gains, indoor climate parameters, human behavior, air quality levels at different times of the day and season, HVAC system operation parameters and operation modes, specific fan powers of ventilation systems, the seasonal energy efficiency of cooling equipment and characteristics of sun protection measures have to be selected.


2021 ◽  
Vol 13 (20) ◽  
pp. 11554
Author(s):  
Fahad Haneef ◽  
Giovanni Pernigotto ◽  
Andrea Gasparella ◽  
Jérôme Henri Kämpf

Nearly-zero energy buildings are now a standard for new constructions. However, the real challenge for a decarbonized society relies in the renovation of the existing building stock, selecting energy efficiency measures considering not only the energy performance but also the economic and sustainability ones. Even if the literature is full of examples coupling building energy simulation with multi-objective optimization for the identification of the best measures, the adoption of such approaches is still limited for district and urban scale simulation, often because of lack of complete data inputs and high computational requirements. In this research, a new methodology is proposed, combining the detailed geometric characterization of urban simulation tools with the simplification provided by “building archetype” modeling, in order to ensure the development of robust models for the multi-objective optimization of retrofit interventions at district scale. Using CitySim as an urban scale energy modeling tool, a residential district built in the 1990s in Bolzano, Italy, was studied. Different sets of renovation measures for the building envelope and three objectives —i.e., energy, economic and sustainability performances, were compared. Despite energy savings from 29 to 46%, energy efficiency measures applied just to the building envelope were found insufficient to meet the carbon neutrality goals without interventions to the system, in particular considering mechanical ventilation with heat recovery. Furthermore, public subsidization has been revealed to be necessary, since none of the proposed measures is able to pay back the initial investment for this case study.


2020 ◽  
Vol 197 ◽  
pp. 02010
Author(s):  
Giada Romano ◽  
Elisa Pennacchia ◽  
Sofia Agostinelli

Buildings with architectural constraints and recognized historical values require a careful design process, aiming to combine the needs of conservation and the adaptation of the buildings to the modern use and its accessibility. The feasible interventions consist in improving the energy performance of the building envelope, in inserting efficient technological systems and using renewable energy sources where possible. The compatibility between the architectural constraints of the building and its more sustainable future use represents a crucial challenge. This work presents the interventions designed and realized on a small villa located in the Prati district, in Rome. Starting from the requests of the client, the primary objective was to create a comfortable house both in the winter and in the summer season, with widespread use of automation systems for managing the utilities. In line with the current energy scenario, the interventions were oriented to energy efficiency, the reduction of polluting emissions, the electrification of utilities and the use of renewable energy sources. The proposed solutions showed high gains in terms of energy saving even if the changes to the building envelope were limited by the desire to preserve the values of the cultural heritage. Therefore, a virtuous refurbishment can effectively respond to current energy efficiency goals.


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.


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