Variation of Time Lag, Decrement Factor and Inside Surface Temperature with Solar Optical Properties of Building Envelope in Different Climatic Zones of India

Author(s):  
Debasish Mahapatra ◽  
T. P. Ashok Babu
2015 ◽  
Vol 11 (2) ◽  
pp. 3017-3022
Author(s):  
Gurban Akhmedov

Results of researches show, that film p-n the structures received by a method of discrete thermal evaporation in a uniform work cycle, are suitable for use in low-voltage devices.  As a result of work are received p-n heterojunctions in thin-film execution, described by high values of differential resistance. Show that, thermo endurance - T0 maybe using as characteristic of thermo endurance of optic materials. If heating flow, destruction temperature and internal surface temperature is measured during test, it is possible to determine value T0 and other necessity characteristics. As a result of the taking test was lead to comparison evaluation of considered materials. Working range of heating flow and up level heating embark have been determined.


2021 ◽  
Vol 13 (8) ◽  
pp. 4175
Author(s):  
Islam Boukhelkhal ◽  
Fatiha Bourbia

The building envelope is the barrier between the interior and exterior environments. It has many important functions, including protecting the interior space from the climatic variations through its envelope materials and design elements, as well as reduction of energy consumption and improving indoor thermal comfort. Furthermore, exterior building sidings, in addition to their aesthetic appearance, can have useful textures for reducing solar gains and providing good thermal insulation performance. This research examined and evaluated the effect of external siding texture and geometry on energy performance. For this objective, a field in situ testing and investigation of surface temperature was carried out on four samples (test boxes) with different exterior textures and different orientations, under the climate zone of Constantine–Algeria during the summer period. The results indicated significant dependability between the exterior texture geometry, the percentage of shadow projected, and external surface temperature. The second part of the research involved a similar approach, exploring the effect of three types of particles with the same appearance but with different thermal characteristics. It was concluded that the natural plant aggregates “palm particles” had the best performance, which contributed to a significant reduction of external surface temperature reaching 4.3 °C, which meant decreasing the energy consumption.


Coatings ◽  
2018 ◽  
Vol 8 (7) ◽  
pp. 248 ◽  
Author(s):  
Benjamin Schumm ◽  
Thomas Abendroth ◽  
Saleh A. Alajlan ◽  
Ahmed M. Almogbel ◽  
Holger Althues ◽  
...  

Multilayered nanocoatings allow outstanding properties with broad potential for glazing applications. Here, we report on the development of a multilayer nanocoating for zinc oxide (ZnO) and antimony doped tin oxide (ATO). The combination of ZnO and ATO thin films with their promising optical properties is a cost-efficient alternative for the production of energy-efficient glazing. It is an effective modification of the building envelope to reduce current high domestic demand of electrical power for air conditioning, especially in hot climates like Saudi Arabia. In this paper, we report the development of a nanocoating based on the combination of ZnO and ATO. Principle material and film investigations were carried out on lab-scale by dip coating with chemical solution deposition (CSD), while with regard to production processes, chemical vapor deposition (CVD) processes were evaluated in a second stage of the film development. It was found that with both processes, high-quality thin films and multilayer coatings with outstanding optical properties can be prepared. While keeping the optical transmission in the visible range at around 80%, only 10% of the NIR (near infrared) and below 1% of UV (ultraviolet) light passes these coatings. However, in contrast to CSD, the CVD process allows a free combination of the multilayer film sequence, which is of high relevance for production processes. Furthermore, it can be potentially integrated in float glass production lines.


Buildings ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 491
Author(s):  
Jorge González ◽  
Carlos Alberto Pereira Soares ◽  
Mohammad Najjar ◽  
Assed N. Haddad

Linking Building Information Modelling and Building Energy Modelling methodologies appear as a tool for the energy performance analysis of a dwelling, being able to build the physical model via Autodesk Revit and simulating the energy modeling with its complement Autodesk Insight. A residential two-story house was evaluated in five different locations within distinct climatic zones to reduce its electricity demand. Experimental Design is used as a methodological tool to define the possible arrangement of results emitted via Autodesk Insight that exhibits the minor electric demand, considering three variables: Lighting efficiency, Plug-Load Efficiency, and HVAC systems. The analysis concluded that while the higher the efficiency of lighting and applications, the lower the electric demand. In addition, the type of climate and thermal characteristics of the materials that conform to the building envelope have significant effects on the energetic performance. The adjustment of different energetic measures and its comparison with other climatic zones enable decision-makers to choose the best combination of variables for developing strategies to lower the electric demand towards energy-efficient buildings.


2002 ◽  
Vol 2 (2) ◽  
pp. 99-101 ◽  
Author(s):  
M.-D. Chou ◽  
R. S. Lindzen ◽  
A. Y. Hou

Abstract. In assessing the iris effect suggested by Lindzen et al. (2001), Fu et al. (2002) found that the response of high-level clouds to the sea surface temperature had an effect of reducing the climate sensitivity to external radiative forcing, but the effect was not as strong as LCH found. The approach of FBH to specifying longwave emission and cloud albedos appears to be inappropriate, and the derived cloud optical properties may not have real physical meaning. The cloud albedo calculated by FBH is too large for cirrus clouds and too small for boundary layer clouds, which underestimates the iris effect.


2019 ◽  
Vol 111 ◽  
pp. 06061
Author(s):  
Sung Ho Choi ◽  
Tae Won Kim ◽  
Jin Chul Park

This research analyzes the time lag, which is a thermal storage performance parameter, when a phase change material is applied to the floor heating system of a mock-up laboratory. The following results are obtained. In terms of the time required for the floor surface temperature to reach 30 °C, the time lag of Room 2 (i.e., the room with the PCM-based floor system) was observed to be 15 min. Additionally, in terms of the time required for the floor surface temperature to decrease to 22 °C, Room 2 exhibited a time lag of 5 h 2 min. Therefore, the study concluded that longer time lags are observed with floor heating systems with PCM.


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