scholarly journals Thermal and Lighting Consumption Savings in Classrooms Retrofitted with Shading Devices in a Hot Climate

Energies ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 2790 ◽  
Author(s):  
Carmen Calama-González ◽  
Rafael Suárez ◽  
Ángel León-Rodríguez
Keyword(s):  
Air Conditioning ◽  
Visual Comfort ◽  
Cooling Systems ◽  
Use Patterns ◽  
Hot Climate ◽  
Shading Devices ◽  
Ambient Systems ◽  
Shading Device ◽  
Current Energy ◽  
Operative Temperatures

Most educational buildings in southern Spain do not meet current energy requirements as weak thermal envelopes and the lack of cooling systems lead to severe discomfort in classrooms, especially when temperatures are above 30 °C. Given that global warming is expected to worsen this situation in coming decades, one of the first steps to be taken is to protect window openings from high levels of solar radiation by adding shading devices to reduce indoor temperatures and improve visual comfort. The aim of this research is to evaluate the reduction in thermal and lighting consumption in a classroom where a solar protection system in the form of an egg-crate shading device was installed. Two classrooms—one with an egg-crate device and another with no shading system—were monitored and compared for a whole year. The use of an egg-crate device in these classrooms reduced indoor operative temperatures during warmer periods while also improving indoor natural illuminance levels. Moreover, annual electric air conditioning consumption decreased by approximately 20%, with a 50% reduction in electric lighting consumption. These savings in electricity were largely conditioned by the use patterns observed in these ambient systems.

scholarly journals Assessment of Indoor Environmental Quality for Retrofitting Classrooms with An Egg-Crate Shading Device in A Hot Climate

2019 ◽  
Vol 11 (4) ◽  
pp. 1078 ◽  
Author(s):  
Carmen Calama-González ◽  
Rafael Suárez ◽  
Ángel León-Rodríguez ◽  
Simone Ferrari
Keyword(s):  
Solar Radiation ◽  
Environmental Quality ◽  
Indoor Environmental Quality ◽  
Cooling Systems ◽  
Incident Solar Radiation ◽  
Hot Climate ◽  
Shading Device ◽  
Operative Temperatures ◽  
Do So

In the Mediterranean climate, a large number of educational buildings suffer from discomfort due mostly to energy-deficient thermal envelopes and a lack of cooling systems. Impending climate change is expected to worsen overheating in classrooms, especially during heatwave periods. Therefore, the protection of window openings to reduce incident solar radiation while maintaining adequate indoor environmental quality must be considered a necessary key focus. The main objective of this research is to assess the influence of an egg-crate shading device on the indoor environmental quality of a classroom in Southern Spain. To do so, two classrooms—with and without this shading device—were simultaneously monitored over a whole year. The implementation of an egg-crate shading device allowed for a significant reduction of the incident solar radiation, both in summer and mid-season (around 45–50%), which objectively slightly conditioned indoor operative temperatures. Given the noticeable influence of the user patterns observed, indoor illuminance was also improved, as the rolling shutters tended to be opened at higher aperture levels.

Effects of Indoor Lighting on Occupants’ Visual Comfort and Eye Health in a Green Building

2010 ◽  
Vol 20 (1) ◽  
pp. 75-90 ◽  
Author(s):  
Taeyon Hwang ◽  
Jeong Tai Kim
Keyword(s):  
Psychological Health ◽  
Green Building ◽  
Personal Characteristics ◽  
Visual Display ◽  
Visual Comfort ◽  
Visual Display Terminal ◽  
Eye Health ◽  
Shading Devices ◽  
Shading Device ◽  
Indoor Lighting

This study investigated the effects of indoor lighting on occupants’ visual comfort and eye health and to contribute to the management and maintenance of buildings. The illuminance of the working plane and windows at Samsung Corporation Headquarters were measured, and 2744 healthy occupants of Samsung Corporation were surveyed regarding the indoor lighting environment via the company’s intranet for 1½ years. This building was certified with the highest ranking by Korea’s Green Building Council. The cumulative data reflected the management and maintenance of the building, such as screen-type shading devices automatically controlled by seasons and time, improvement of visual display terminal glare by the veiling reflection on monitors, efficiency of artificial lighting arrays, and so on. The data were analysed for occupants’ visual comfort and eye health. The result showed that daylighting could improve the occupants’ psychological health and productivity. The screen-type shading device could intercept direct sunlight and reduce annoyance glare. However, the indoor lighting and visual environment of the building were poor. After examining the questionnaire feedback concerning improvements, the occupants’ annoyance ratio was significantly reduced, and approximately 5% of the occupants’ annoyance ratio was deemed to be caused by personal characteristics related to the lighting of the environment.

scholarly journals Performance Evaluation of Control Methods for PV-Integrated Shading Devices

Energies ◽  
2020 ◽  
Vol 13 (12) ◽  
pp. 3171
Author(s):  
Sung Kwon Jung ◽  
Youngchul Kim ◽  
Jin Woo Moon
Keyword(s):  
Tilt Angle ◽  
Control Method ◽  
System Modeling ◽  
The Other ◽  
Control Methods ◽  
Visual Comfort ◽  
Ann Model ◽  
Indoor Space ◽  
Shading Devices ◽  
Shading Device

This study aimed to develop a building-integrated photovoltaic (BIPV) device and optimal control methods that increase the photovoltaic (PV) efficiency and visual comfort of the indoor space. A louver-type PV-integrated shading device was suggested and an artificial neural networks (ANN) model was developed to predict PV electricity output, work plane illuminance, and daylight glare index (DGI). The slat tilt angle of the shading device was controlled to maximize PV electricity output based on three different strategies: one without visual comfort constraints, and the other two with visual comfort constraints: work plane illuminance and DGI. Optimal tilt angle was calculated using predictions of the ANN. Experiments were conducted to verify the system modeling and to evaluate the performance of the shading device. Experiment results revealed that the ANN model successfully predicted the PV output, work plane illuminance, and DGI. The PV-integrated shading device was more efficient in producing electricity than the conventional wall-mount PV systems, the control method without visual comfort constraints was most efficient in generating electricity than the other two with such constraints, and excluding the constraints resulted in less comfortable visual environment and reduced energy benefit. From the results analysis, it can be concluded that based on the accurate predictions, the PV-integrated shading device controlled using the proposed methods produced more electricity compared to the wall-mount counterpart.

scholarly journals Atrium Impact on a School-Building: Thermal Performance in a Hot Climate

Proceedings ◽  
2020 ◽  
Vol 38 (1) ◽  
pp. 18 ◽  
Author(s):  
Romero-Odero ◽  
Galán-Marín ◽  
Rivera-Gómez
Keyword(s):  
Climate Change ◽  
20Th Century ◽  
Air Conditioning ◽  
Passive Cooling ◽  
Cooling Systems ◽  
Hot Climate ◽  
Higher Temperature ◽  
Passive Cooling Systems ◽  
Air Circulation

The process of climate change has increased the planet’s mean temperature. An example of this are the 44.3 °C registered in July in the cities of Córdoba and Seville (Spain). In this scenario, the educational centers in Andalusia, mostly built during the 20th century, are unable to reach the thermal comfort inside the classrooms throughout the year, without resorting to mechanical air conditioning procedures. This study simultaneously monitors indoors, outdoors and transitional spaces of a case study to verify the effectiveness of the passive cooling systems and the Atrium thermal effect of the building. Our results demonstrate that temperatures inside classrooms are influenced by the orientation and their air circulation (atrium or outdoor) and as expected, the higher temperature in the building are registered in the classrooms in the last floor.

scholarly journals Efficient Shading Device as an Important Part of Daylightophil Architecture; a Designerly Framework of High-Performance Architecture for an Office Building in Tehran

Energies ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 8272
Author(s):  
Hassan Bazazzadeh ◽  
Barbara Świt-Jankowska ◽  
Nasim Fazeli ◽  
Adam Nadolny ◽  
Behnaz Safar ali najar ◽  
...  
Keyword(s):  
High Performance ◽  
Energy Performance ◽  
Climatic Conditions ◽  
Office Buildings ◽  
Building Performance ◽  
Visual Comfort ◽  
Different Seasons ◽  
Good Potential ◽  
Shading Devices ◽  
Shading Device

(1) Background: considering multiple, and somehow conflicting, design objectives can potentially make achieving a high-performance design a complex task to perform. For instance, shading devices can dramatically affect the building performance in various ways, such as energy consumption and daylight. This paper introduces a novel procedure for designing shading devices as an integral part of daylightophil architecture for office buildings by considering daylight and energy performance as objectives to be optimal. (2) Methods: to address the topic, a three-step research method was used. Firstly, three different window shades (fixed and dynamic) were modeled, one of which was inspired by traditional Iranian structures, as the main options for evaluation. Secondly, each option was evaluated for energy performance and daylight-related variables in critical days throughout the year in terms of climatic conditions and daylight situations (equinoxes and solstices including 20 March, 21 June, 22 September, and 21 December). Finally, to achieve a reliable result, apart from the results of the comparison of three options, all possible options for fixed and dynamic shades were analyzed through a multi-objective optimization to compare fixed and dynamic options and to find the optimal condition for dynamic options at different times of the day. (3) Results: through different stages of analysis, the findings suggest that, firstly, dynamic shading devices are more efficient than fixed shading devices in terms of energy efficiency, occupants’ visual comfort, and efficient use of daylight (roughly 10%). Moreover, through analyzing dynamic shading devices in different seasons and different times of the year, the optimal form of this shading device was determined. The results indicate that considering proper shading devices can have a significant improvement on achieving high-performance architecture in office buildings. This implies good potential for daylightophil architecture, but would require further studies to be confirmed as a principle for designing office buildings.

scholarly journals Performance Characteristics of Solid-Desiccant Evaporative Cooling Systems

Energies ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 2574 ◽  
Author(s):  
Ramadas Narayanan ◽  
Edward Halawa ◽  
Sanjeev Jain
Keyword(s):  
Air Conditioning ◽  
Natural Ventilation ◽  
Waste Heat ◽  
Numerical Study ◽  
Evaporative Cooling ◽  
Peak Load ◽  
Dew Point ◽  
Low Grade ◽  
Subtropical Climate ◽  
Cooling Systems

Air conditioning accounts for up to 50% of energy use in buildings. Increased air-conditioning-system installations not only increase total energy consumption but also raise peak load demand. Desiccant evaporative cooling systems use low-grade thermal energy, such as solar energy and waste heat, instead of electricity to provide thermal comfort. This system can potentially lead to significant energy saving, reduction in carbon emissions, and it has a low dew-point operation and large capacity range. Their light weight, simplicity of design, and close-to-atmospheric operation make them easy to maintain. This paper evaluates the applicability of this technology to the climatic conditions of Brisbane, Queensland, Australia, specifically for the residential sector. Given the subtropical climate of Brisbane, where humidity levels are not excessively high during cooling periods, the numerical study shows that such a system can be a potential alternative to conventional compression-based air-conditioning systems. Nevertheless, the installation of such a system in Brisbane’s climate zone requires careful design, proper selection of components, and a cheap heat source for regeneration. The paper also discusses the economy-cycle options for this system in such a climate and compares its effectiveness to natural ventilation.

The study of solar absorption air-conditioning systems

2005 ◽  
Vol 16 (4) ◽  
pp. 59-66 ◽  
Author(s):  
V Mittal ◽  
KS Kasana ◽  
NS Thakur
Keyword(s):  
Air Conditioning ◽  
Lithium Bromide ◽  
Cooling Systems ◽  
Solar Absorption ◽  
Air Conditioning System ◽  
Heating And Cooling ◽  
Absorption Cooling ◽  
Solar Powered ◽  
Solar Absorption Cooling ◽  
Air Conditioning Systems

An air-conditioning system utilizing solar energy would generally be more efficient, cost wise, if it was used to provide both heating and cooling requirements in the building it serves. Various solar powered heating systems have been tested extensively, but solar powered air conditioning systems have received very little attention. Solar powered absorption cooling systems can serve both heating and cooling requirements in the building it serves. Many researchers have studied the solar absorption air conditioning system in order to make it economically and technically viable. But still, much more research in this area is needed. This paper will help many researchers working in this area and provide them with fundamental knowledge on absorption systems, and a detailed review on the past efforts in the field of solar absorption cooling systems with the absorption pair of lithium-bromide and water. This knowledge will help them to start the parametric study in order to investigate the influence of key parameters on the overall system performance.

scholarly journals Thermal Comfort Study Based on PMV-PPD in the Building of a Screening Center for COVID-19

2021 ◽  
Author(s):  
Danial Mohammadi ◽  
Simin Nasrabadi
Keyword(s):  
Thermal Stress ◽  
Energy Consumption ◽  
Thermal Comfort ◽  
Air Conditioning ◽  
Thermal Condition ◽  
R Software ◽  
Air Conditioning System ◽  
Thermal Index ◽  
Predicted Mean Vote ◽  
Hot Climate

Background: One way to achieve a standard heating, ventilating, and air conditioning system with maximum satisfaction is to use a thermal index to identify and determine the thermal comfort of people. In this study we intend to evaluate thermal comfort based on PMV-PPD (Predicted Mean Vote/Predicted Percentage Dissatisfied) model in workers of screening center for COVID-19. Methods: The study period was from March 1 to October 31, 2020. In this study, we used the ISO 7730 model to determinate PMV-PPD index. PMV index was used to determine thermal comfort at different scales in Birjand city with arid and hot climate. All data were analyzed using R software (version 3.3.0) and IBM SPSS statistics softwares. Results: The maximum and minimum recorded physical PMV values in the study period were observed in June as (2.09 ± 0.03) and March as (-1.27 ± 0.14), respectively. The amplitude of the thermal sense in the study period was varied between slightly cool (-1.5) and warm (+2.5). The PPD in spring was 40% which indicated slightly warm to hot condition. Conclusions: The October was the only month during the study in which thermal stress was in comfort or neutral thermal condition.  Our results suggest that thermal comfort has dimensions and indices which are helpful in managing energy consumption.

scholarly journals Evaluating the Effect of External Horizontal Fixed Shading Devices’ Geometry on Internal Air Temperature, Daylighting and Energy Demand in Hot Dry Climate. Case Study of Ghardaïa, Algeria

Buildings ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 348
Author(s):  
Sahar Magri Elouadjeri ◽  
Aicha Boussoualim ◽  
Hassan Ait Haddou
Keyword(s):  
Solar Radiation ◽  
Parametric Analysis ◽  
Energy Demand ◽  
Daylighting Simulation ◽  
Simulation Results ◽  
Shading Devices ◽  
Heating Loads ◽  
Shading Device ◽  
The City

The present study investigates the effect of fixed external shading devices’ geometry on thermal comfort, daylighting and energy demand for cooling and heating in the hot and dry climate of the city of Ghardaïa (Algeria). A parametric analysis was performed by using three software: RADIANCE 2.0 and DAYSIM 3.1 for daylighting simulation and TRNSYS.17 for thermal dynamic simulation. Three shading device parameters were assessed: the spacing between slats, the tilted angle and the slats installation. The vertical shading angle “VSA” is fixed; it is equal to the optimum shading angle measured for Ghardaïa. The simulation results indicate that fixed external shading devices have a significant impact on decreasing the energy demand for cooling; however, they are unable to reduce the total energy demand since they significantly increase heating loads. It was found that fixed external shading devices remove all risks associated with glare in summer by decreasing illuminance close to the window; however, they do not improve daylighting performance in winter because of glare. We note that even if the vertical shading angle “VSA” was the same for all cases, these did not present the same thermal and luminous behavior. This is mainly due to the amount and the way that the solar radiation penetrates space.

scholarly journals Calculation of Water Evaporative Cooling Systems in Animal Husbandry

2020 ◽  
pp. 35-38
Author(s):  
N.N. Novikov ◽  
Keyword(s):  
Air Conditioning ◽  
Evaporation Rate ◽  
Evaporative Cooling ◽  
Animal Husbandry ◽  
Water Evaporation ◽  
Cooling Systems ◽  
Temperature And Humidity ◽  
Hot Weather ◽  
Livestock Building ◽  
Air Exchange

A method for calculating the parameters of the microclimate in a livestock building using water-evaporative air conditioning is described. It makes it possible to choose a rational temperature and humidity conditions for a room in hot weather, calculate the required air exchange, water evaporation rate and select the appropriate equipment.

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