Impact of Shape on Building Energy Use in Tunisia

Solar Energy ◽  
2006 ◽  
Author(s):  
Kais Ouertani ◽  
Moncef Krarti
Keyword(s):  
Energy Use ◽  
Residential Buildings ◽  
Energy Performance ◽  
Analysis Tool ◽  
Architectural Form ◽  
Relative Compactness ◽  
Building Shape ◽  
Heating And Cooling ◽  
Building Form ◽  
The Impact

This paper investigates the impact of the architectural form on the energy performance of residential buildings in Tunisia. A relative compactness is defined as one indicator of a building shape. The results of the analysis indicate that a significant decrease in heating and cooling energy requirements can be obtained by minimizing the relative compactness of detached residential houses. A simplified analysis tool, suitable for early design process, is developed to assess the impact of building form on its energy performance for several cities in Tunisia.

scholarly journals Evaluation of Urban-Scale Building Energy-Use Models and Tools—Application for the City of Fribourg, Switzerland

2021 ◽  
Vol 13 (4) ◽  
pp. 1595
Author(s):  
Valeria Todeschi ◽  
Roberto Boghetti ◽  
Jérôme H. Kämpf ◽  
Guglielmina Mutani
Keyword(s):  
Machine Learning ◽  
Energy Use ◽  
Residential Buildings ◽  
Building Energy ◽  
Energy Performance ◽  
Space Heating ◽  
Engineering Model ◽  
Building Energy Use ◽  
The Impact ◽  
The City

Building energy-use models and tools can simulate and represent the distribution of energy consumption of buildings located in an urban area. The aim of these models is to simulate the energy performance of buildings at multiple temporal and spatial scales, taking into account both the building shape and the surrounding urban context. This paper investigates existing models by simulating the hourly space heating consumption of residential buildings in an urban environment. Existing bottom-up urban-energy models were applied to the city of Fribourg in order to evaluate the accuracy and flexibility of energy simulations. Two common energy-use models—a machine learning model and a GIS-based engineering model—were compared and evaluated against anonymized monitoring data. The study shows that the simulations were quite precise with an annual mean absolute percentage error of 12.8 and 19.3% for the machine learning and the GIS-based engineering model, respectively, on residential buildings built in different periods of construction. Moreover, a sensitivity analysis using the Morris method was carried out on the GIS-based engineering model in order to assess the impact of input variables on space heating consumption and to identify possible optimization opportunities of the existing model.

scholarly journals The impact of window-related thermal bridging on energy use in MURB retrofits using 2-d heat transfer modelling for full window thermal bridge analysis

2021 ◽  
Author(s):  
Jessica Coburn
Keyword(s):  
Energy Use ◽  
Residential Buildings ◽  
Ghg Emissions ◽  
Energy Performance ◽  
Energy Reduction ◽  
Excessive Heat ◽  
Thermal Bridging ◽  
Post War ◽  
Frame Insulation ◽  
The Impact

There is significant in the GTA for GHG emissions reduction through energy retrofit measures of the more than 2000 post-war multi-unit residential buildings. Overcladding is an effective energy reduction strategy; however, it is crucial to properly detail window installation to avoid thermal bridging in a retrofit situation, as there may be excessive heat loss and condensation at this junction. This paper examines the thermal bridging potential at the window-wall interface in an EIFS overcladding retrofit scenario for a typical MURB retrofit. The research used the software THERM to compare influence of three typical window-wall interface on the energy performance of the window and wall. The analysis examined the position of the window within the frame, insulation placement around the window perimeter. It was found that window placement within the wall section and detailing at the opening do significantly affect the wall’s overall thermal performance, determining that design improvement should be considered and quantified in retrofit energy reduction strategies.

scholarly journals The impact of window-related thermal bridging on energy use in MURB retrofits using 2-d heat transfer modelling for full window thermal bridge analysis

2021 ◽  
Author(s):  
Jessica Coburn
Keyword(s):  
Energy Use ◽  
Residential Buildings ◽  
Ghg Emissions ◽  
Energy Performance ◽  
Energy Reduction ◽  
Excessive Heat ◽  
Thermal Bridging ◽  
Post War ◽  
Frame Insulation ◽  
The Impact

There is significant in the GTA for GHG emissions reduction through energy retrofit measures of the more than 2000 post-war multi-unit residential buildings. Overcladding is an effective energy reduction strategy; however, it is crucial to properly detail window installation to avoid thermal bridging in a retrofit situation, as there may be excessive heat loss and condensation at this junction. This paper examines the thermal bridging potential at the window-wall interface in an EIFS overcladding retrofit scenario for a typical MURB retrofit. The research used the software THERM to compare influence of three typical window-wall interface on the energy performance of the window and wall. The analysis examined the position of the window within the frame, insulation placement around the window perimeter. It was found that window placement within the wall section and detailing at the opening do significantly affect the wall’s overall thermal performance, determining that design improvement should be considered and quantified in retrofit energy reduction strategies.

scholarly journals Assessment of the Impact of Occupants’ Behavior and Climate Change on Heating and Cooling Energy Needs of Buildings

Energies ◽  
2020 ◽  
Vol 13 (23) ◽  
pp. 6468
Author(s):  
Gianmarco Fajilla ◽  
Marilena De Simone ◽  
Luisa F. Cabeza ◽  
Luís Bragança
Keyword(s):  
Climate Change ◽  
Natural Ventilation ◽  
Residential Buildings ◽  
Energy Performance ◽  
Future Scenarios ◽  
Occupant Behavior ◽  
Heating And Cooling ◽  
Energy Needs ◽  
Energy Simulations ◽  
The Impact

Energy performance of buildings is a worldwide increasing investigated field, due to ever more stringent energy standards aimed at reducing the buildings’ impact on the environment. The purpose of this paper is to assess the impact that occupant behavior and climate change have on the heating and cooling needs of residential buildings. With this aim, data of a questionnaire survey delivered in Southern Italy were used to obtain daily use profiles of natural ventilation, heating, and cooling, both in winter and in summer. Three climatic scenarios were investigated: The current scenario (2020), and two future scenarios (2050 and 2080). The CCWorldWeatherGen tool was used to create the weather files of future climate scenarios, and DesignBuilder was applied to conduct dynamic energy simulations. Firstly, the results obtained for 2020 demonstrated how the occupants’ preferences related to the use of natural ventilation, heating, and cooling systems (daily schedules and temperature setpoints) impact on energy needs. Heating energy needs appeared more affected by the heating schedules, while cooling energy needs were mostly influenced by both natural ventilation and usage schedules. Secondly, due to the temperature rise, substantial decrements of the energy needs for heating and increments of cooling energy needs were observed in all the future scenarios where in addition, the impact of occupant behavior appeared amplified.

scholarly journals Climate Change Scenarios and Their Implications on the Energy Performance of Hellenic Non-Residential Buildings

2021 ◽  
Vol 13 (23) ◽  
pp. 13005
Author(s):  
Kalliopi G. Droutsa ◽  
Simon Kontoyiannidis ◽  
Constantinos A. Balaras ◽  
Athanassios A. Argiriou ◽  
Elena G. Dascalaki ◽  
...  
Keyword(s):  
Climate Change ◽  
Energy Use ◽  
Residential Buildings ◽  
Energy Performance ◽  
Climate Change Scenarios ◽  
Baseline Scenario ◽  
Climate Data ◽  
Building Stock ◽  
Heating And Cooling ◽  
The Future

It is important to understand how the climate is changing in order to prepare for the future, adapt if necessary, and, most importantly, take proper precautionary measures to alleviate major negative impacts. This work investigates the potential impacts of climate change on the anticipated energy performance of the existing Hellenic building stock until the end of the century. The assessment considers average climatic projections for two future time periods, one for the near and one for the distant future, following two representative concentration pathways (RCPs). The first one is a baseline scenario (RCP8.5) representing the highest greenhouse gas emissions. The second is an intermediate stabilization scenario (RCP4.5), assuming the imposition of conservative emissions mitigation policies. The future climate data are generated for 62 cities throughout Greece. As a case study, the work focuses on Hellenic non-residential (NR) whole buildings, analyzing available data collected during about 2500 energy audits of real NR buildings. The available data are used to assess the buildings’ heating and cooling demand and energy use. The annual average air temperature for Greece in 2050 is projected to increase by 1.5 K for the RCP4.5 scenario and by 1.9 K for the RCP8.5 scenario. In 2090, the increase is estimated to reach 1.7 K and 4.2 K, respectively. Accordingly, if the existing NR buildings are not renovated, the average heating energy use is expected to decrease by 22–26% in 2050 and by 23–52% in 2090. On the other hand, the average cooling energy use is expected to increase by 24–30% in 2050 and by 28–66% in 2090.

scholarly journals Towards Sustainable Energy Retrofitting, a Simulation for Potential Energy Use Reduction in Residential Buildings in Palestine

Energies ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3876
Author(s):  
Sameh Monna ◽  
Adel Juaidi ◽  
Ramez Abdallah ◽  
Aiman Albatayneh ◽  
Patrick Dutournie ◽  
...  
Keyword(s):  
Energy Consumption ◽  
Energy Use ◽  
Energy Savings ◽  
Residential Buildings ◽  
Residential Building ◽  
Simulation Models ◽  
Water Heating ◽  
Heating And Cooling ◽  
Space Cooling ◽  
Cooling Loads

Since buildings are one of the major contributors to global warming, efforts should be intensified to make them more energy-efficient, particularly existing buildings. This research intends to analyze the energy savings from a suggested retrofitting program using energy simulation for typical existing residential buildings. For the assessment of the energy retrofitting program using computer simulation, the most commonly utilized residential building types were selected. The energy consumption of those selected residential buildings was assessed, and a baseline for evaluating energy retrofitting was established. Three levels of retrofitting programs were implemented. These levels were ordered by cost, with the first level being the least costly and the third level is the most expensive. The simulation models were created for two different types of buildings in three different climatic zones in Palestine. The findings suggest that water heating, space heating, space cooling, and electric lighting are the highest energy consumers in ordinary houses. Level one measures resulted in a 19–24 percent decrease in energy consumption due to reduced heating and cooling loads. The use of a combination of levels one and two resulted in a decrease of energy consumption for heating, cooling, and lighting by 50–57%. The use of the three levels resulted in a decrease of 71–80% in total energy usage for heating, cooling, lighting, water heating, and air conditioning.

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 Outer wall with thermal barrier. Impact of the barrier on heat losses and CO2 emissions

2020 ◽  
Vol 29 (2) ◽  
pp. 223-233
Author(s):  
Ewa Figiel ◽  
Dorota Leciej-Pirczewska
Keyword(s):  
Meteorological Data ◽  
Renewable Energy Sources ◽  
Outer Wall ◽  
Energy Performance ◽  
Temperate Climate ◽  
Thermal Barrier ◽  
Single Family ◽  
Heating And Cooling ◽  
The Impact ◽  
Supply Systems

New demands for lowering energy consumption of buildings lead to many new solutions including, amongst others, the introduction of an outer wall thermal barrier for both heating and cooling effect. The analysed thermo-active-wall-barrier is a water-based system, where the pipes are embedded in the wall construction. It enables the use of a low-temperature barrier medium for space heating, thereby increasing the efficiency of all potential energy supply systems using renewable energy sources. The pipes form an active thermal barrier for heat transfer between the outer and the heated space. There are many possibilities to place the pipes in the wall for example in the case of energetic thermo-modernisation. Our research and calculations have shown that thermo-active-wall-barrier is sensitive to the location of pipes. The following paper also provides a study of the impact of thermal barrier on a building’s energy performance. The analysis was conducted for a single-family house in a temperate climate based on parameters taken from one of the Polish meteorological data-bases. Calculations using current procedure of evaluating building energy performance show, that the thermal barrier can contribute to signifi cant reduction of transmission energy loss thus lowering the environmental impact.

scholarly journals ENERGY EFFICIENCY IN RESIDENTIAL BUILDINGS, LESS STRAIGHT FORWARD THEN PRESUMED

2018 ◽  
Vol 13 (1) ◽  
Author(s):  
Hugo Hens
Keyword(s):  
Energy Efficiency ◽  
Energy Efficient ◽  
Energy Use ◽  
Low Voltage ◽  
Residential Buildings ◽  
Primary Energy ◽  
Heating And Cooling ◽  
Net Zero ◽  
Energy Conserving ◽  
New Construction

Since the 1990s, the successive EU directives and related national or regional legislations require new construction and retrofits to be as much as possible energy-efficient. Several measures that should stepwise minimize the primary energy use for heating and cooling have become mandated as requirement. However, in reality, related predicted savings are not seen in practice. Two effects are responsible for that. The first one refers to dweller habits, which are more energy-conserving than the calculation tools presume. In fact, while in non-energy-efficient ones, habits on average result in up to a 50% lower end energy use for heating than predicted. That percentage drops to zero or it even turns negative in extremely energy-efficient residences. The second effect refers to problems with low-voltage distribution grids not designed to transport the peaks in electricity whensunny in summer. Through that, a part of converters has to be uncoupled now and then, which means less renewable electricity. This is illustrated by examples that in theory should be net-zero buildings due to the measures applied and the presence of enough photovoltaic cells (PV) on each roof. We can conclude that mandating extreme energy efficiency far beyond the present total optimum value for residential buildings looks questionable as a policy. However, despite that, governments and administrations still seem to require even more extreme measurements regarding energy efficiency.

scholarly journals Impacts of Microclimate Conditions on the Energy Performance of Buildings in Urban Areas

Buildings ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 189 ◽  
Author(s):  
Javanroodi ◽  
M.Nik
Keyword(s):  
Urban Areas ◽  
Energy Demand ◽  
Weather Conditions ◽  
Energy Performance ◽  
Urban Morphology ◽  
Weather Data ◽  
Architectural Form ◽  
Energy Performance Of Buildings ◽  
Microclimate Conditions ◽  
The Impact

Urbanization trends have changed the morphology of cities in the past decades. Complex urban areas with wide variations in built density, layout typology, and architectural form have resulted in more complicated microclimate conditions. Microclimate conditions affect the energy performance of buildings and bioclimatic design strategies as well as a high number of engineering applications. However, commercial energy simulation engines that utilize widely-available mesoscale weather data tend to underestimate these impacts. These weather files, which represent typical weather conditions at a location, are mostly based on long-term metrological observations and fail to consider extreme conditions in their calculation. This paper aims to evaluate the impacts of hourly microclimate data in typical and extreme climate conditions on the energy performance of an office building in two different urban areas. Results showed that the urban morphology can reduce the wind speed by 27% and amplify air temperature by more than 14%. Using microclimate data, the calculated outside surface temperature, operating temperature and total energy demand of buildings were notably different to those obtained using typical regional climate model (RCM)–climate data or available weather files (Typical Meteorological Year or TMY), i.e., by 61%, 7%, and 21%, respectively. The difference in the hourly peak demand during extreme weather conditions was around 13%. The impact of urban density and the final height of buildings on the results are discussed at the end of the paper.

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