Numerical study of the energy efficiency of the building envelope containing multi-alveolar structures under Tunisian weather conditions

2022 ◽  
Vol 0 (0) ◽  
Author(s):  
Nour Lajimi ◽  
Nour Ben Taher ◽  
Noureddine Boukadida
Keyword(s):  
Energy Efficiency ◽  
Energy Consumption ◽  
Thermal Behavior ◽  
Thermal Insulation ◽  
Numerical Study ◽  
Thermal Inertia ◽  
Building Envelope ◽  
Winter Period ◽  
Alveolar Structure ◽  
Major Interest

Abstract The study of the thermal inertia of buildings is a subject of major interest. The thermal insulation and the nature of the wall sensitively modify the inertia of the building and are the solutions to improve the energy efficiency of the envelope. The roof is well exposed to solar radiation in summer and contributes to significant losses in winter due to convective exchanges. To lead to a thermal comfort, a thermal insulation is necessary. In this context, we carry out a numerical study of the thermal behavior of a building with two zones in variable meteorological conditions for a Tunisian climate (region of Sousse) based on the thermoelectric analogy and using the nodal method as a numerical method. The object of this work is to study the effect of the thermal inertia of the roof equipped with a multi-alveolar structure on the thermal behavior of the air inside the room and on its energy consumption. Taking into account the energy input of occupant, a complete model was established to increase the accuracy of the calculations. The results show that the multi-alveolar structure placed on the outside of the roof reduces energy consumption during the winter period when the alveolar structure is placed in the conductive direction and during the summer period when the alveolar structure is placed in the insulate direction.

scholarly journals The Role of Emitters, Heat Pump Size, and Building Massive Envelope Elements on the Seasonal Energy Performance of Heat Pump-Based Heating Systems

Energies ◽  
2020 ◽  
Vol 13 (19) ◽  
pp. 5098
Author(s):  
Matteo Dongellini ◽  
Paolo Valdiserri ◽  
Claudia Naldi ◽  
Gian Luca Morini
Keyword(s):  
Energy Consumption ◽  
Heat Pump ◽  
Numerical Study ◽  
Thermal Inertia ◽  
Heating System ◽  
Energy Performance ◽  
Building Envelope ◽  
Control Logic ◽  
Pump System ◽  
Heat Pump System

The influence of emitters, heat pump size and building envelope thermal inertia was investigated on the energy consumption of a heat pump-based heating system with a numerical study performed with the dynamic software TRNSYS. An algorithm based on a Thermal Inertia Control Logic (TICL), which can exploit the capability of the building envelope to store thermal energy, has been applied. When the proposed algorithm is employed, the indoor air temperature set-point is increased when the outdoor temperature is larger than the bivalent temperature of the building-heat pump system. Different configurations of the heating system were simulated considering either convective (fan-coil) or radiant (radiant floor) emitters coupled to a variable-speed air-to-water heat pump. Simulations have been carried out considering a reference building derived from the IEA SHC Task 44 and evaluating the influence of the proposed control logic on both the heat pump seasonal energy performance and the internal comfort conditions perceived by the building users. The obtained results highlight how the introduced TICL can guarantee the use of downsized heat pumps, coupled to radiant emitters, with a significant enhancement of the seasonal performance factor up to 10% and a slight improvement of comfort conditions. On the other hand, when convective terminal units are considered the proposed logic is not effective and the overall energy consumption of the system increases up to 15%.

Riqualificazione energetica e bioedilizia in Italia: lo stato dell'arte

2012 ◽  
pp. 74-88
Author(s):  
Livio de Santoli
Keyword(s):  
Energy Efficiency ◽  
Renewable Energy ◽  
Energy Consumption ◽  
Fossil Fuels ◽  
Building Materials ◽  
Heat Pumps ◽  
Building Envelope ◽  
International Standards ◽  
Solar Panels ◽  
Water Heaters

Building sustainability, in term of energy efficiency, low-impact building materials, renewable energy, has experienced significant growth during the past years. In response to the growing dependence on fossil fuels and importations, due in part to the increase of energy consumption in the residential sector (in 2009 46,9 Mtep, 3% more than 2008) and the recent European directives (i.e. EU 2009/28/CE) requiring CO2 emissions cut of up to 13% in 2020, there is interest in promoting energy efficiency and renewable energy technologies, which are suitable for residential applications. In this paper we present an overview on actions related to minimization of buildings energy consumption in Italy. Prevalent line of action is to improve the energy performances of building envelope (Dlgs 192/05) using insulated frames, walls and roofs and replacing heat generators with condensing boilers. In addition to national directives, ONRE Report 2011 (National Observatory on building regulations) shows that 831 Municipalities (10% more than 2010) establish mandatory targets for insulation, photovoltaic solar panels, solar water heaters, heat pumps use, correct buildings orientation, saving of water resource and local materials use. In addiction an efficient energy rating of the buildings could promote the spread of energy efficiency measurement and consequently facilitate their implementation. The new energy rating system should meet international standards, regarding environment and energy aspects, and respect territorial needs.

scholarly journals Thermal behavior of premises equipped with different alveolar structures

2015 ◽  
Vol 19 (3) ◽  
pp. 929-938
Author(s):  
Nour Lajimi ◽  
Noureddine Boukadida
Keyword(s):  
Heat Transfer ◽  
Thermal Behavior ◽  
Air Temperature ◽  
Numerical Study ◽  
Convection Heat Transfer ◽  
Convection Heat ◽  
Point Temperature ◽  
Set Point ◽  
Alveolar Structure ◽  
Vertical Walls

This paper presents a numerical study of local thermal behavior. Vertical walls are equipped with alveolar structure and/or simple glazing in East, South and West frontages. Local temperature is assumed to be variable with time or imposed at set point temperature. Results principally show that the simple glazing number has a sensitive effect on convection heat transfer and interior air temperature. They also show that the diode effect is more sensitive in winter. The effect of alveolar structure and simple glazing on the power heating in case with set point temperature is also brought out.

scholarly journals Determination of Optimum Envelope of Religious Buildings in Terms of Thermal Comfort and Energy Consumption: Mosque Cases

Energies ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 6597
Author(s):  
Ahmet Bircan Atmaca ◽  
Gülay Zorer Gedik ◽  
Andreas Wagner
Keyword(s):  
Thermal Properties ◽  
Energy Consumption ◽  
Thermal Comfort ◽  
Thermal Insulation ◽  
Energy Savings ◽  
Gain Factor ◽  
Building Envelope ◽  
Comfort Level ◽  
Humid Climate ◽  
Savings Rate

Mosques are quite different from other building types in terms of occupant type and usage schedule. For this reason, they should be evaluated differently from other building types in terms of thermal comfort and energy consumption. It is difficult and probably not even necessary to create homogeneous thermal comfort in mosques’ entire usage area, which has large volumes and various areas for different activities. Nevertheless, energy consumption should be at a minimum level. In order to ensure that mosques are minimally affected by outdoor climatic changes, the improvement of the properties of the building envelope should have the highest priority. These optimal properties of the building envelope have to be in line with thermal comfort in mosques. The proposed method will be a guide for designers and occupants in the design process of new mosques or the use of existing mosques. The effect of the thermal properties of the building envelope on energy consumption was investigated to ensure optimum energy consumption together with an acceptable thermal comfort level. For this purpose, a parametric simulation study of the mosques was conducted by varying optical and thermal properties of the building envelope for a temperature humid climate zone. The simulation results were analyzed and evaluated according to current standards, and an appropriate envelope was determined. The results show that thermal insulation improvements in the roof dome of buildings with a large volume contributed more to energy savings than in walls and foundations. The use of double or triple glazing in transparent areas is an issue that should be considered together with the solar energy gain factor. Additionally, an increasing thickness of thermal insulation in the building envelope contributed positively to energy savings. However, the energy savings rate decreased after a certain thickness. The proposed building envelope achieved a 33% energy savings compared to the base scenario.

scholarly journals Evaluation of the Summer Overheating Phenomenon in Reinforced Concrete and Cross Laminated Timber Residential Buildings in the Cold and Severe Cold Regions of China

Energies ◽  
2020 ◽  
Vol 13 (23) ◽  
pp. 6305
Author(s):  
Haibo Guo ◽  
Lu Huang ◽  
Wenjie Song ◽  
Xinyue Wang ◽  
Hongnan Wang ◽  
...  
Keyword(s):  
Energy Efficiency ◽  
Energy Consumption ◽  
Reinforced Concrete ◽  
Building Materials ◽  
Residential Buildings ◽  
Building Envelope ◽  
Thermal Design ◽  
Cold Regions ◽  
Cross Laminated Timber ◽  
Design Standard

As the climate changed in recent years, an increase in summer indoor temperatures in severe cold and cold regions of China has started to affect thermal comfort. However, the local design standard for energy efficiency does not recognize this phenomenon. This paper reports the potential overheating phenomenon in residential buildings and examines the rationale for the current thermal designs adopted in severe cold and cold regions of China. In this study, the two most commonly used building materials, reinforced concrete (RC) and cross laminated timber (CLT), are used separately in the design of an 18-story residential building envelope located in six different cities in the severe cold and cold regions. The energy consumption and indoor operative temperatures during the operation of these buildings are simulated using Integrated Environmental Solutions Virtual Environment (IES VE). The results demonstrate that both the RC and the CLT buildings experience varying degrees of overheating in any climate subregion. The CLT buildings have longer overheating hours compared to the RC buildings, especially in the cold regions. The results also indicate that for apartments on higher stories, the cooling energy consumption and indoor temperature also increase gradually. The research results suggest that the local design standard for energy efficiency needs to be adjusted by adding thermal design methods for summer to reduce the periods of overheating.

Thermal Bridges Minimizing through Typical Details in Low Energy Designing

2014 ◽  
Vol 899 ◽  
pp. 62-65 ◽  
Author(s):  
Rastislav Ingeli ◽  
Boris Vavrovič ◽  
Miroslav Čekon
Keyword(s):  
Energy Efficiency ◽  
Thermal Insulation ◽  
Energy Demand ◽  
Building Energy ◽  
Building Envelope ◽  
Low Energy ◽  
Building Energy Efficiency ◽  
Low Energy Buildings ◽  
Thermal Bridges ◽  
The Impact

Energy demand reduction in buildings is an important measure to achieve climate change mitigation. It is essential to minimize heat losses in designing phase in accordance of building energy efficiency. For building energy efficiency in a mild climate zone, a large part of the heating demand is caused by transmission losses through the building envelope. Building envelopes with high thermal resistance are typical for low-energy buildings in general. In this sense thermal bridges impact increases by using of greater thickness of thermal insulation. This paper is focused on thermal bridges minimizing through typical system details in buildings. The impact of thermal bridges was studied by comparative calculations for a case study of building with different amounts of thermal insulation. The calculated results represent a percentage distribution of heat loss through typical building components in correlation of various thicknesses of their thermal insulations.

scholarly journals Exploration of Microalgae Photobioreactor (PBR) in Tropical Climate Building Envelope

2020 ◽  
Vol 5 (14) ◽  
pp. 263-278
Author(s):  
Mohd Tajul Izrin Mohd Tajul Hasnan ◽  
Puteri Mayang Bahjah Zaharin
Keyword(s):  
Energy Efficiency ◽  
Energy Consumption ◽  
Open Access ◽  
Peer Review ◽  
Publishing House ◽  
Tropical Climate ◽  
Building Envelope ◽  
Building Envelopes ◽  
International Publishing ◽  
Open Access Article

The building sector in Malaysia consumes up to half of the electricity generated in the country. Therefore, there are needs to have a continuous effort to promote microalgae as part of an innovative building envelope system. This paper intends to investigate the potentiality of implementing the microalgae photobioreactor (PBR) in building envelopes in Malaysia. The findings from the precedent studies are synthesised into ten (10) parameters and translated into four (4) design modules. In conclusion, the suggested parameters are crucial in establishing microalgae photobioreactor (PBR) as a suitable prospect for energy efficiency in building envelopes in the tropical climate. Keywords: energy consumption; microalgae; photobioreactor; building envelope. eISSN: 2398-4287© 2020. The Authors. Published for AMER ABRA cE-Bs by e-International Publishing House, Ltd., UK. This is an open access article under the CC BYNC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). Peer–review under responsibility of AMER (Association of Malaysian Environment-Behaviour Researchers), ABRA (Association of Behavioural Researchers on Asians) and cE-Bs (Centre for Environment-Behaviour Studies), Faculty of Architecture, Planning & Surveying, Universiti Teknologi MARA, Malaysia. DOI: https://doi.org/10.21834/ebpj.v5i14.2166

scholarly journals Retrofitting a Building’s Envelope: Sustainability Performance of ETICS with ICB or EPS

2019 ◽  
Vol 9 (7) ◽  
pp. 1285 ◽  
Author(s):  
José D. Silvestre ◽  
André M. P. Castelo ◽  
José J. B. C. Silva ◽  
Jorge M. C. L. de Brito ◽  
Manuel D. Pinheiro
Keyword(s):  
Life Cycle ◽  
Energy Consumption ◽  
Thermal Insulation ◽  
Carbon Footprint ◽  
Energy Performance ◽  
Building Envelope ◽  
Expanded Polystyrene ◽  
Insulation Material ◽  
Economic Dimension ◽  
Heating And Cooling

This paper analyses the environmental, energy, and economic performances of the External Thermal Insulation Composite System (ETICS) using agglomerated insulation cork board (ICB) or expanded polystyrene (EPS) as insulation material applied in the energetic renovation of the building envelope during a 50-year study period. A comparison between ETICS using ICB and EPS, for the same time horizon, is also presented. The environmental balance is based on “Cradle to Cradle” (C2C) Life Cycle Assessment (LCA), focusing on the carbon footprint and consumption of nonrenewable primary energy (PE-NRe). The characteristics of these products in terms of thermal insulation, the increased energy performance provided by their installation for retrofit of the buildings’ envelope, and the resulting energy savings are considered in the energy balance. The estimation of the C2C carbon and PE-NRe saved is considered in the final balance between the energy and environmental performances. ETICS with ICB is environmentally advantageous both in terms of carbon footprint and of PE-NRe. In fact, the production stage of ICB is less polluting, while EPS requires lower energy consumption to fulfil the heating and cooling needs of a flat, due to its lower U-Value, and its lower acquisition cost results in a lower C2C cost. Comparing both ETICS’ alternatives with reference solutions, it was found that the latter only perform better in the economic dimension, and only for an energy consumption to fulfil less than 25% of the heating and cooling needs. This paper represents an advance to the current state-of-the-art by including all the life-cycle stages and dimensions of the LCA in the analysis of solutions for energy renovation of building envelopes.

scholarly journals Study of the Improvement on Energy Efficiency for a Building in the Mediterranean Area by the Installation of a Green Roof System

Energies ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1246 ◽  
Author(s):  
Elisa Peñalvo-López ◽  
Javier Cárcel-Carrasco ◽  
David Alfonso-Solar ◽  
Iván Valencia-Salazar ◽  
Elias Hurtado-Pérez
Keyword(s):  
Energy Efficiency ◽  
Energy Consumption ◽  
Energy Demand ◽  
Simulation Analysis ◽  
Green Roof ◽  
Mediterranean Area ◽  
Substantial Improvement ◽  
Winter Period ◽  
Reduction Of Energy Consumption ◽  
Heating Energy Demand

Rooftop gardens ona building have proved to be a good way to improve its storm water management, but many other benefits can be obtained from the installation of these systems, such as reduction of energy consumption, decrease of the heat stress, abatement on CO2 emissions, etc. In this paper, the effect from the presence of these rooftop gardens on abuilding’s energy consumption has been investigated by experimental campaigns using a green roof ona public building in a Mediterranean location in Spain. The obtained results demonstrate a substantial improvement by the installation of the green roof onthe building’s cooling energy demand for a standard summer day, in the order of 30%, and a reduction, about 15%, in the heating energy demand for a winter day. Thus, given the longer duration of the summer conditions along the year, a noticeable reduction on energy demand could be obtained. Simulation analysis, using commercial software TRNSYS code, previously calibrated using experimental data for typical summer and winter days, allows for the extrapolation to the entire year of these results deducing noticeable improvement in energy efficiency, in the order of 19%, but with an increase of 6% in the peak power during the winter period.

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