Investigating the thermal performance and Overall Thermal Transfer Value (OTTV) of air-conditioned buildings under the effect of adjacent shading against solar radiation

2021 ◽  
Vol 44 ◽  
pp. 103211
Author(s):  
Lok Shun Chan
Keyword(s):  
Solar Radiation ◽  
Thermal Performance ◽  
Thermal Transfer

scholarly journals Analysis of the potential use of Trombe walls in Brazil: design recommendations

2020 ◽  
Vol 5 ◽  
pp. 4
Author(s):  
Fernando Antonio de Melo Sá Cavalcanti ◽  
Rosana Maria Caram
Keyword(s):  
Solar Radiation ◽  
Computer Simulations ◽  
Thermal Performance ◽  
Natural Ventilation ◽  
Solar Heating ◽  
Heating And Cooling ◽  
Heated Air ◽  
Trombe Wall ◽  
Potential Use ◽  
Passive Strategy

In this paper, the thermal performance of a standard environment was evaluated based on the use of a Trombe wall with different configurations and types of use, as the potential for using this passive strategy is still little studied in Brazil. This device is capable of absorbing energy from solar radiation by heating the air in this greenhouse and this heated air can be directed to the interior or exterior of the building depending on the purpose. This air can be used to heat the room or cool it by means of natural ventilation. The analysis of this research was based on a series of computer simulations using the EnergyPlus software, version 7.0 in order to quantify and classify the thermal performance of a standard environment equipped with this component, under the various construction configurations. Both for heating and cooling environments. The use of Trombe walls improved the thermal comfort of users in buildings located in Brazil, depending on the climate where they are located, promoting natural ventilation and passive solar heating, allowing the potential of this device to be investigated in the most diverse Brazilian regions.

scholarly journals The Effects of Courtyards on the Thermal Performance of a Vernacular House in a Hot-Summer and Cold-Winter Climate

Energies ◽  
2019 ◽  
Vol 12 (6) ◽  
pp. 1042 ◽  
Author(s):  
Shimeng Hao ◽  
Changming Yu ◽  
Yuejia Xu ◽  
Yehao Song
Keyword(s):  
Solar Radiation ◽  
Thermal Performance ◽  
Natural Ventilation ◽  
Field Measurements ◽  
Ground Level ◽  
Active Role ◽  
Thermal Mass ◽  
Cold Winter ◽  
Winter Climate ◽  
Climate Zones

Achieving comfort in hot summer and cold winter (HSCW) climate zones can be challenging, since the climate is characterized by high temperatures in the summer and relatively colder temperatures in the winter. Courtyards, along with other semi-open spaces such as verandas and overhangs, play an important role in mitigating outdoor climate fluctuations. In this research, the effects of courtyards on the thermal performance of vernacular houses in HSCW climate zones were studied via field measurements and computational fluid dynamics (CFD) models. The selected courtyard house was a representative vernacular timber dwelling situated in the southeast of Chongqing, China. The indoor and outdoor air temperature measurements revealed that the courtyard did play an active role as a climatic buffer and significantly reduced the temperature’s peak value in the summer, while during the winter, the courtyard prevented the surrounding rooms from receiving direct solar radiation, and thus to some extent acted as a heat barrier. The contributions of thermal mass are quite limited in this area, due to insufficient solar radiation in winter and general building operations. The natural ventilation mechanism of courtyard houses in HSCW zones was further studied through CFD simulations. The selected opened courtyard was compared to an enclosed structure with similar building configurations. The airflow patterns driven by wind and buoyancy effects were first simulated separately, and then together, to illustrate the ventilation mechanisms. The simulation results show that the courtyard’s natural ventilation behavior benefited from the proper openings on ground level.

Thermal Performance Characteristics of Porous Media Receiver Exposed to Concentrated Solar Radiation

2017 ◽  
Vol 143 (5) ◽  
pp. 04017013 ◽  
Author(s):  
Yatao Ren ◽  
Hong Qi ◽  
Jingwen Shi ◽  
Qin Chen ◽  
Yuqing Wang ◽  
...  
Keyword(s):  
Porous Media ◽  
Solar Radiation ◽  
Thermal Performance ◽  
Performance Characteristics ◽  
Concentrated Solar Radiation

Material Properties of Refractory Concrete under High Temperature

2015 ◽  
Vol 1126 ◽  
pp. 155-160
Author(s):  
Stanislav Šťastník ◽  
František Šot ◽  
Jiří Vala
Keyword(s):  
High Temperature ◽  
Solar Radiation ◽  
Physical Properties ◽  
Material Properties ◽  
Refractory Concrete ◽  
Thermal Storage ◽  
Thermal Transfer ◽  
The Core

The paper presents the validation of physical properties of refractory concrete with heavy filling, using the measurements under high temperature, assumed for the construction of a thermal storage. The whole system, consisting of the storage core and of the insulation container, is characterized by non-stationary thermal transfer, supplied from solar radiation into the core. The validation of behaviour of the system (including its sleeping state and the dynamics of charging and discharging) is needed for the optimization of its size parameters.

scholarly journals Simulation and design of collector array units within large systems

2019 ◽  
Author(s):  
Jianhua Fan ◽  
Zhiyong Tian ◽  
Simon Furbo ◽  
Weiqiang Kong ◽  
Daniel Tschopp
Keyword(s):  
Solar Radiation ◽  
Thermal Performance ◽  
Global Radiation ◽  
Diffuse Radiation ◽  
Solar Heating ◽  
Heating Systems ◽  
Global Irradiance ◽  
Radiation Data ◽  
Large Systems ◽  
Beam Component

Solar radiation data is necessary for the design of solar heating systems and used to estimate the thermal performance of solar heating plants. Compared to global irradiance, the direct beam component shows much more variability in space and time. The global radiation split into beam and diffuse radiation on collector plane is important for the evaluation of the performance of different collector types and collector field designs.

Development of a Computer Model for Solar Simulation and Shaded Fenestration Design

2001 ◽  
Author(s):  
John Kie-Whan Oh ◽  
Jeffrey S. Haberl ◽  
Larry O. Degelman
Keyword(s):  
Heat Transfer ◽  
Solar Radiation ◽  
Computer Model ◽  
Thermal Performance ◽  
Energy Efficient ◽  
Design System ◽  
The Sun ◽  
Physical Test ◽  
Shading Device ◽  
Solar Simulation

Abstract The goal of this study was to develop a computer model for solar radiation calculation and display and a shaded fenestration design system that can be used by architectural and engineering designers. This computerized model calculates the amount of insolation and transmitted solar radiation through a shaded window as well as the heat transfer through it. The computer model, called Shaded Fenestration Design (SFD), contains various functions relating to solar simulation such as: display of the sunpath diagrams and the accompanying shading mask protractor, display of the hourly intensity of solar radiation onto the path of the sun for horizontal and vertical surfaces at varying off-south azimuths, and simulating the thermal performance of a shaded fenestration. The model also provides graphical aids for energy-efficient shading device design with use of various kinds of sunpath diagrams and solar radiation diagrams. The model performs solar radiation simulation using the methods developed in the ASHRAE Handbook, Duffie and Beckman, and Kreider and Rabl. An anisotrophic sky model was applied for the calculation of solar radiation on a titled surface and the transmitted solar radiation through a single-glazed window. A part of the model was validated experimentally using a physical test box and was also compared to simulated results from the DOE-2 program; however, the validation is not included in this paper.

Experimental Investigation of Thermal Performance of a Multipurpose PV Solar Collector Wall With Phase Change Material

2019 ◽  
Vol 141 (6) ◽  
Author(s):  
Preeda Chantawong
Keyword(s):  
Experimental Investigation ◽  
Solar Radiation ◽  
Phase Change ◽  
Phase Change Material ◽  
Thermal Performance ◽  
Hot Water ◽  
External Layer ◽  
Indoor Temperature ◽  
Pv Panel ◽  
Change Material

The author reports an experimental investigation of the thermal performance of a multipurpose photovoltanic (PV) solar wall with phase change material (PVSW-PCM). The PVSW-PCM configuration was made of double layers. The external layer consists of a 12 Wp photovoltaic panel attached to a 15 cm thick PCM tank integrating water pipes. The internal wall is an ordinary clear glass pane. There is an 8 cm air gap between the two layers. The PVSW-PCM was integrated into the southern side of a small house of 4.05 m3 volume built by autoclaved aerated concrete block walls 0.07 m thick. On top of the external layer, three glass blocks (3 × 0.2 × 0.2 cm2) are installed to ensure indoor illumination. The absorbed solar radiation by the PV panel and PCM heats the water in the pipes and the air in the gap. The hot water produced is stored in a 10 liters tank located near the roof. At the inner lower part (room side) and the external upper part (ambient) of the gap, a small DC fan (12 V, 0.48 A) box was installed. The fans were connected to the PV panel directly to enhance indoor ventilation. The investigation considered both natural (fans OFF) and PV assisted ventilation. Another similar house without the PVSW-PCM referred to as glass wall (GW) was built and used as a reference for comparison. The experimental results revealed that the indoor temperature of the PVSW-PCM house was considerably lower than that of the GW house. Moreover, the PVSW-PCM could produce hot water temperature of 55–62 °C and induce a ventilation rate proportional to the intensity of solar radiation. Indoor illumination was sufficient for general house use. Therefore, the PVSW-PCM offers a new alternative for architects and engineers to reduce electric energy use for producing hot water and ventilation and save electrical energy consumption of air conditioner, as the indoor temperature is lower than that of the conventional house.

Experimental comparison of summer thermal performance of green roof (GR), double skin roof (DSR) and cool roof (CR) in lightweight rooms in subtropical climate

2021 ◽  
pp. 174425912110405
Author(s):  
Erlin Meng ◽  
Jiawang Yang ◽  
Ruonan Cai ◽  
Bo Zhou ◽  
Junqi Wang
Keyword(s):  
Heat Flux ◽  
Solar Radiation ◽  
Thermal Performance ◽  
Surface Heat Flux ◽  
Internal Surface ◽  
Surface Heat ◽  
Experimental Comparison ◽  
Subtropical Climate ◽  
Weather Factors ◽  
Solar Altitude

Subtropical climate is characterized by high solar altitude angle in summer which causes the roof get more heat through solar radiation. GR, DSR, and CR all can decrease solar radiation heat gain of the roof. However, few researches have been done to the comparison of the thermal performance of these three roofs, especially in subtropical climate. In this study, four rooms were built separately with GR, DSR, CR, and ordinary roof (OR). The experiment was done from July 23 to August 4. Results showed that stabilities of the indoor air temperature of the four rooms were: DSR room > GR room > CR room > OR room. The GR, CR, and DSR can reduce the external surface temperature by 13.7°C, 12.0°C, and 4.8°C during the day while bring a temperature rise of 2.3°C, 1.9°C, and 0.9°C at night. Correlation analysis results showed that the internal surface heat flux of GR and DSR were negative correlated with weather factors while internal surface heat flux of OR and CR were positive correlated with weather factors. This study can give support to the selection between GR, DSR, and CR.

Experiment of a Flat Plate Solar Water Heater Collector with Modified Design and Thermal Performance Analysis

2014 ◽  
Vol 624 ◽  
pp. 332-338 ◽  
Author(s):  
Shouquat Hossain ◽  
Ali Wadi Abbas ◽  
Jeyraj Selvaraj ◽  
Ferdous Ahmed ◽  
Nasrudin Bin Abd Rahim
Keyword(s):  
Heat Transfer ◽  
Solar Radiation ◽  
Flat Plate ◽  
Thermal Performance ◽  
Solar Water Heater ◽  
Water Heater ◽  
Pipe Surface ◽  
Solar Water ◽  
Useful Heat ◽  
Absorber Surface

An investigation is reported of the thermal performance of a flat plate solar water heater with a circulating absorber pipe surface. The thermal performance of the 2-side parallel serpentine flow solar water heater depends significantly on the heat transfer rate between the absorber surface and the water, and on the amount of solar radiation incident on the absorber surface. The modified pipe arrangement has a higher characteristic length for convective heat transfer from the absorber to the water, in addition to having more surface area exposed to solar radiation. It means during the operation of water heater, more solar energy is converted into useful heat. However, this modification has reduced the efficiency of the system marginally.

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