scholarly journals Are ICFs Suitable Building Envelope Solutions For Mediterranean Climatic Conditions? A Critical Analysis Concerning Thermal Properties And Annual Energy Performances

Author(s):  
Cristina Carpino ◽  
Roberto Bruno ◽  
Piero Bevilacqua ◽  
Natale Arcuri
2020 ◽  
pp. 50-64
Author(s):  
Kuladeep Kumar Sadevi ◽  
Avlokita Agrawal

With the rise in awareness of energy efficient buildings and adoption of mandatory energy conservation codes across the globe, significant change is being observed in the way the buildings are designed. With the launch of Energy Conservation Building Code (ECBC) in India, climate responsive designs and passive cooling techniques are being explored increasingly in building designs. Of all the building envelope components, roof surface has been identified as the most significant with respect to the heat gain due to the incident solar radiation on buildings, especially in tropical climatic conditions. Since ECBC specifies stringent U-Values for roof assembly, use of insulating materials is becoming popular. Along with insulation, the shading of the roof is also observed to be an important strategy for improving thermal performance of the building, especially in Warm and humid climatic conditions. This study intends to assess the impact of roof shading on building’s energy performance in comparison to that of exposed roof with insulation. A typical office building with specific geometry and schedules has been identified as base case model for this study. This building is simulated using energy modelling software ‘Design Builder’ with base case parameters as prescribed in ECBC. Further, the same building has been simulated parametrically adjusting the amount of roof insulation and roof shading simultaneously. The overall energy consumption and the envelope performance of the top floor are extracted for analysis. The results indicate that the roof shading is an effective passive cooling strategy for both naturally ventilated and air conditioned buildings in Warm and humid climates of India. It is also observed that a fully shaded roof outperforms the insulated roof as per ECBC prescription. Provision of shading over roof reduces the annual energy consumption of building in case of both insulated and uninsulated roofs. However, the impact is higher for uninsulated roofs (U-Value of 3.933 W/m2K), being 4.18% as compared to 0.59% for insulated roofs (U-Value of 0.33 W/m2K).While the general assumption is that roof insulation helps in reducing the energy consumption in tropical buildings, it is observed to be the other way when insulation is provided with roof shading. It is due to restricted heat loss during night.


2018 ◽  
Vol 16 (1) ◽  
pp. 24-31
Author(s):  
Wasiska Iyati ◽  
◽  
Eryani Nurma Yulita ◽  
Jusuf Thojib ◽  
Heru Sufianto ◽  
...  

The narrow land in big cities such as Jakarta, increases the amount of high rise building, especially multi-storey office building. Office building consumes much energy to provide air conditioning to meet the thermal comfort inside the building. On the other hand, the building shape, building envelope, and building orientation to the sun's position are the main factors in building design aspects that affect the amount of cooling load. This study aims to investigate the impact of the aspect ratio or the ratio of the longer dimension of an oblong plan to the shorter, on external heat gain of multi-storey office building. Variables examined include the transparent and solid area of building envelope, the total area of the surface of the building envelope in any orientation, and the volume of the building, as well as the influence of those proportion on the external heat gain. This study uses mathematical calculations to predict the cooling load of the building, particularly external heat gain through the walls, roof and glass, as well as comparative analysis of models studied. The study also aims to generate the design criteria of building form and proportion of multi-storey office buildings envelope with lower external heat gain. In Jakarta climatic conditions, the result on rectangular building plan with aspect ratio of 1 to 4 shows that the external heat gain did not differ significantly, and the smallest heat gain is found on the aspect ratio of 1.8. Results also showed that the greater aspect ratio, the greater reduction of external heat gain obtained by changing the orientation of the longest side facing east-west into the north-south, about 2.79% up to 42.14% on the aspect ratio of 1.1 to 4. In addition, it is known that in same building volume, changing the number of floors from 10 to 50 can improve the external heat gain almost twice.


Energies ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 6597
Author(s):  
Ahmet Bircan Atmaca ◽  
Gülay Zorer Gedik ◽  
Andreas Wagner

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.


2018 ◽  
Vol 7 (3) ◽  
pp. 1861
Author(s):  
Neveen Y. Azmy ◽  
Rania E. Ashmawy

Windows play a significant role as they largely influence the energy load. Although there are many studies on the energy-efficient windows design, there is still a lack in information about the mutual impact of windows’ size, position and orientation on the energy loads. In this paper, the effect of different window positions and orientations on the energy consumption in a typical room in an administrative building that is located in the hot climatic conditions of Cairo city, Egypt is considered. This case study has been modeled and analyzed to achieve good environmental performance for architectural space, as well as assessing its impact on the amount of natural lighting required by using the Energy Plus program. The study concludes that the WWR (Window Wall Ratio) 20% square north-oriented upper  opening consumes 25% lower energy than the rectangular 3:1 opening in the lower west-oriented façade. The upper openings are the highest in terms of light intensity, as they cover about 50% of the room area. The WWR 30% rectangular north-oriented upper 3:1 opening consumes 29% lower energy than the rectangular lower 3:1opening in the façade. Regarding light intensity, the upper openings are the best for natural lighting as the light covers more than 60% of the room area.                                                                                                                                                               


Author(s):  
Daniele Fiaschi ◽  
Giampaolo Manfrida ◽  
Luigi Russo

The use of heavy fluids (typically refrigerants) for tests on turbomachinery equipment, like centrifugal compressors, under similitude with real working conditions is a common practice in the test facilities of manufacturers. This practice leads to the release of the test gas to the environment, mainly coming from seals, test circuit connections, valve gaskets and from operations of circuit assembling/disassembling necessary to replace or service the machine under test. The spatial distribution and flow of these emissions inside the test building is a complex issue, which depends on the specific circuit features, location of sources, geometry and openings of the building and variable climatic conditions of the location. For a preliminary assessment of the health and safety conditions, a NIST computational package — including a CFD solver — was applied. The aim was to validate the applicability and reliability of this tool, which was developed for other types of buildings; from the industrial side, knowledge of the diffusion scenario is important to define test protocols to guarantee acceptable emissions levels for manpower in working areas. The industrial building is organized in multiple inside workspaces. The concentration of the contaminant in the area of the test benches, determined by the internal fluid dynamics, is calculated with the CFD solver included in the NIST package. In the building, air motion is only affected by natural ventilation. For this reason, the interactions between the outside and the interior climatic and microclimatic parameters must be considered, taking into account also the different possible assumptions about the daily management of the openings of the building envelope. Several cases of release and dispersion of heavy fluid inside the working areas, under different boundary conditions, were considered. The sensitivity of the results to the different seasonal conditions was assessed and discussed. The complex internal geometry of the building was simulated by a combination of single zone models. The results showed an expectable presence of test gas emissions in the neighborhood of the test area and the possibility of buoyancy effects within the large building. A relatively stable concentration of the test gas emissions resulted from the application of the model, which was affected only by substantial variations of the climatic conditions.


2014 ◽  
Vol 982 ◽  
pp. 27-31 ◽  
Author(s):  
Václav Kočí ◽  
Miloš Jerman ◽  
Jiří Maděra ◽  
Robert Černý

This paper aims at computational simulation of effect of zeolite admixture on service life of concrete building envelope from point of view of freeze/thaw resistance. Hygrothermal behavior of two types of concrete is studied in this paper: reference concrete without any admixtures and zeolite concrete with 40 % zeolite as cement replacement. The computations are performed using computer simulation tool HEMOT, which processes the input parameters using finite element method. The simulation is assumed under dynamic climatic conditions of Prague. As the results of the computational simulations showed, assuming analyzed amount of zeolite, any positive effect of on freeze/thaw resistance was not found related to unprotected building envelope. However, the results indicated, hygrothermal performance of zeolite concrete can be very considerate to applied external layers and thus extend their service life.


Sign in / Sign up

Export Citation Format

Share Document