scholarly journals Influence of Thermal Design performance of Envelope structure on Indoor Thermal Environment in Dry-Hot and Dry-Cold areas

2019 ◽  
Vol 136 ◽  
pp. 05009
Author(s):  
Chen Jie ◽  
Luo Zhixing ◽  
Yang Liu

Thermal performance is considered to be a key measure in building sustainability. One of the technologies used in the current building sustainable design is the high thermal mass techniques. The application of this type of technology is widely used in traditional architecture. The paper aims at studying the effect of both high thermal insulation and high thermal mass techniques in buildings dynamic behaviour in Dry-Hot and Dry-Cold Climate. The two techniques can lead to conflicting requirements when considering winter and summer conditions. Therefore, it is necessary to identify insulation measures that conserve the mass dynamic behavior. Experimental investigations were carried out on a single - family house to characterize the behavior of one room with high thermal mass in different seasons. Thermal simulations made it possible to explore different retrofit configurations. Different thermal mass and thermal insulation were compared on internal surface temperature. The analysis shows that the most suitable intervention is both high thermal insulation and high thermal mass techniques, and the decrease of the absorption coefficient of the outer surface is beneficial to improve the overall level of solar radiation.

2021 ◽  
Vol 2042 (1) ◽  
pp. 012159
Author(s):  
M Haj Hussein ◽  
S Monna ◽  
A Juaidi ◽  
A Barlet ◽  
M Baba ◽  
...  

Abstract The presented study aims to evaluate the effect of thermal mass in heavyweight construction in residential buildings in Palestine on indoor thermal environment using a building performance simulation tool. The most used residential building types, shapes and sizes were used as typical models for indoor environment performance simulation. The paper used a sensitivity analysis for four different scenarios according to the location of thermal insulation in the wall for two climatic zones, when no heating and cooling was used. The building material’s thermal properties, infiltration, activities, time schedule, electric lighting and glazing selection were based on onsite studies. The results show that the internal thermal mass of the studied buildings influences their thermal performance and future potential energy demand for heating and cooling. Buildings with insulation positioned on the outside, with high thermal mass and high thermal time constant showed the best thermal performance for different climatic zones, whereas buildings without thermal insulation or with insulation from the inside showed the worst thermal performance. The position of thermal insulation will affect potential energy demand for heating and cooling in the residential buildings.


2020 ◽  
Vol 172 ◽  
pp. 01009
Author(s):  
Pavel Kopecký ◽  
Kamil Staněk ◽  
Jan Tywoniak

Wooden floors were traditionally used in brick apartment houses built at the turn of 20th century in many European cities. Thermal renovation of such houses often involves thermal insulation at interior side of external walls. Internal insulation makes microclimate in the vicinity of wooden beam ends colder and more humid. The real-scale experiment involving a part of wooden floor connected to a 30 cm thick masonry wall was monitored for two consecutive years. Measured data were used to compare microclimate in sealed and open joist pockets. Joist pockets were either placed in the masonry wall with plaster on both sides or placed in the same masonry wall insulated on the interior side (vapour open thermal insulation system). The measured results indicate that the sealing tape alone is not sufficient to keep the relative humidity in joist pockets below 85 % in cold climate and under high internal moisture load. The paper concludes that reasonable trade-off between thermal efficiency, thermal comfort and moisture safety is difficult to reach for masonry with internal insulation and wooden floors. Sealing provisions complemented by tempering of joist pockets are considered as two key technical measures for reliable hygro-thermal performance of wooden beam ends in full-brick masonry with interior thermal insulation in cold temperate climate.


Aerospace ◽  
2021 ◽  
Vol 8 (6) ◽  
pp. 150
Author(s):  
Yeon-Kyu Park ◽  
Geuk-Nam Kim ◽  
Sang-Young Park

The CANYVAL-C (CubeSat Astronomy by NASA and Yonsei using a virtual telescope alignment for coronagraph) is a space science demonstration mission that involves taking several images of the solar corona with two CubeSats—1U CubeSat (Timon) and 2U CubeSat (Pumbaa)—in formation flying. In this study, we developed and evaluated structural and thermal designs of the CubeSats Timon and Pumbaa through finite element analyses, considering the nonlinearity effects of the nylon wire of the deployable solar panels installed in Pumbaa. On-orbit thermal analyses were performed with an accurate analytical model for a visible camera on Timon and a micro propulsion system on Pumbaa, which has a narrow operating temperature range. Finally, the analytical models were correlated for enhancing the reliability of the numerical analysis. The test results indicated that the CubeSats are structurally safe with respect to the launch environment and can activate each component under the space thermal environment. The natural frequency of the nylon wire for the deployable solar panels was found to increase significantly as the wire was tightened strongly. The conditions of the thermal vacuum and cycling testing were implemented in the thermal analytical model, which reduced the differences between the analysis and testing.


2012 ◽  
Vol 174-177 ◽  
pp. 1533-1536
Author(s):  
Hai Rong Yang ◽  
Yan Yuan

The sandwich external wall panel is made of fireproof Paper Honeycomb Board (PHB) as kernel material, and the external surface is covered by colorful extruded steel board, while the internal surface is coated with the thermal insulating frothing ceramic board or the calcium silicate board, which works as the insulating layer or protecting layer of the panel. Two types of formation design are suggested, i.e., Type-A and Type-B. After corresponding thermal calculation, the maximum thermal transmission factor is determined as 0.424W/(m2• K), which complies with the threshold stipulated in the National Code for external wall panel used in cold climate area. The newly designed wall panel will save 65% of energy when compared with the traditional one made in 1980.


2000 ◽  
Vol 41 (1) ◽  
pp. 177-185 ◽  
Author(s):  
G. Andreottola ◽  
P. Foladori ◽  
M. Ragazzi

The aim of this study was to evaluate the performance of a full-scale upgrading of an existing RBC wastewater treatment plant with a MBBR (Moving Bed Biofilm Reactor) system, installed in a tank previously used for sludge aerobic digestion. The full-scale plant is located in a mountain resort in the North-East of Italy. Due to the fact that the people varied during the year's seasons (2000 resident people and 2000 tourists) the RBC system was insufficient to meet the effluent standards. The MBBR applied system consists of the FLOCOR-RMP®plastic media with a specific surface area of about 160 m2/m3 (internal surface only). Nitrogen and carbon removal from wastewater was investigated over a 1-year period, with two different plant lay-outs: one-stage (only MBBR) and two stage system (MBBR and rotating biological contactors in series). The systems have been operated at low temperature (5–15°C). 50% of the MBBR volume (V=79 m3) was filled. The organic and ammonium loads were in the average 7.9 gCOD m−2 d−1 and 0.9 g NH4−N m−2 d−1. Typical carbon and nitrogen removals in MBBR at temperature lower than 8°C were respectively 73% and 72%.


2012 ◽  
Vol 476-478 ◽  
pp. 1589-1595
Author(s):  
Yi Ping Zhu ◽  
Xi Liao ◽  
Shu Yun Wu ◽  
Jing Luo ◽  
Yuan Jiang ◽  
...  

Based on indoor thermal environment test and questionnaire surveys, the paper studies on thermal insulation capacity and indoor thermal environment of the vernacular dwellings in Wei-he Plain of Shaanxi Province, China, and analyses their heating methods and application status. Besides, the popularity of sustainable techniques in local area has been evaluated and summarized. Moreover, the paper discusses the present problems in local indoor thermal environment and energy-saving status.


2014 ◽  
Vol 10 (1) ◽  
pp. 172-183 ◽  
Author(s):  
Sushil B. Bajracharya

This paper seeks to investigate into the aspects of thermal performance of traditional residential buildings in traditional settlements of Kathmandu valley. This study proceeds to analyze the detailed field data collected, with a view to identify the indoor thermal environment with respect to outdoor thermal environment in different seasons. This paper also compares the thermal performance of traditional buildings with modern residential buildings of traditional settlements of the valley. There is a regression analysis to obtain information about the thermal environment of different traditional and modern residential buildings with different conditions. The paper concludes that, thermal performance of traditional residential building, adapted in various ways to the changing thermal regime for thermal comfort is better than that of contemporary buildings.DOI: http://dx.doi.org/10.3126/jie.v10i1.10898Journal of the Institute of Engineering, Vol. 10, No. 1, 2014,  pp. 172–183


Energies ◽  
2019 ◽  
Vol 12 (17) ◽  
pp. 3354 ◽  
Author(s):  
Piselli ◽  
Pisello ◽  
Saffari ◽  
Gracia ◽  
Cotana ◽  
...  

Cool roof effectiveness in improving building thermal-energy performance is affected by different variables. In particular, roof insulation level and climate conditions are key parameters influencing cool roofs benefits and whole building energy performance. This work aims at assessing the role of cool roof in the optimum roof configuration, i.e., combination of solar reflectance capability and thermal insulation level, in terms of building energy performance in different climate conditions worldwide. To this aim, coupled dynamic thermal-energy simulation and optimization analysis is carried out. In detail, multi-dimensional optimization of combined building roof thermal insulation and solar reflectance is developed to minimize building annual energy consumption for heating–cooling. Results highlight how a high reflectance roof minimizes annual energy need for a small standard office building in the majority of considered climates. Moreover, building energy performance is more sensitive to roof solar reflectance than thermal insulation level, except for the coldest conditions. Therefore, for the selected building, the optimum roof typology presents high solar reflectance capability (0.8) and no/low insulation level (0.00–0.03 m), except for extremely hot or cold climate zones. Accordingly, this research shows how the classic approach of super-insulated buildings should be reframed for the office case toward truly environmentally friendly buildings.


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