scholarly journals Thermophysics Analysis of Office Buildings with a Temperature–Humidity Coupling Strategy Under Hot-Arid Climatic Conditions

2021 ◽  
Vol 42 (8) ◽  
Author(s):  
Mohammed Bensafi ◽  
Houari Ameur ◽  
Noureddine Kaid ◽  
Siamak Hoseinzadeh ◽  
Saim Memon ◽  
...  
Keyword(s):  
Thermal Comfort ◽  
Ambient Air ◽  
Arid Environment ◽  
Considerable Effect ◽  
Climatic Conditions ◽  
Thermal Fields ◽  
Northwestern Region ◽  
Coupling Strategy ◽  
American Society ◽  
The University

AbstractThis study investigates the determining parameters of thermal comfort of office in an arid hot-arid environment of Bechar, located in the northwestern region of Algeria, in which the vertical walls of the room and the roof are subjected to solar irradiations and the floor is considered to be adiabatic. The solar flux is calculated by the ASHRAE (American Society of Heating, Refrigerating and Air-Conditioning Engineers) method. The predicted results are validated against the experimental results of the meteorological station of the ENERGARID research laboratory at the University of Bechar (Algeria). The characteristics of the ambient air flow are performed by using the computational fluid dynamics (CFD) software (Fluent). The flow fields, thermal fields, and humidity are investigated. An elaborated computer program (with Delphi language) is utilized to evaluate the temperature–humidity coupling as the most essential factors of the thermal comfort. A significant impact of dynamic temperatures and humidity on thermal comfort has been observed, especially in this hot-arid environment. Besides, a considerable effect of the flow velocity has been remarked. From the obtained results and to provide the best thermal comfort in such arid regions, the range of air velocity inside the building is recommended to be between 0.2 m·s−1 and 0.3 m·s−1.

scholarly journals Investigating Applicability of Evaporative Cooling Systems for Thermal Comfort of Poultry Birds in Pakistan

2020 ◽  
Vol 10 (13) ◽  
pp. 4445
Author(s):  
Hafiz M. U. Raza ◽  
Hadeed Ashraf ◽  
Khawar Shahzad ◽  
Muhammad Sultan ◽  
Takahiko Miyazaki ◽  
...  
Keyword(s):  
Heat Stress ◽  
Thermal Comfort ◽  
Developing Economies ◽  
Low Cost ◽  
Evaporative Cooling ◽  
Ambient Air ◽  
Climatic Conditions ◽  
Maximum Temperature ◽  
Poultry Birds ◽  
The City

In the 21st century, the poultry sector is a vital concern for the developing economies including Pakistan. The summer conditions of the city of Multan (Pakistan) are not comfortable for poultry birds. Conventionally, swamp coolers are used in the poultry sheds/houses of the city, which are not efficient enough, whereas compressor-based systems are not economical. Therefore, this study is aimed to explore a low-cost air-conditioning (AC) option from the viewpoint of heat stress in poultry birds. In this regard, the study investigates the applicability of three evaporative cooling (EC) options, i.e., direct EC (DEC), indirect EC (IEC), and Maisotsenko-cycle EC (MEC). Performance of the EC systems is investigated using wet-bulb effectiveness (WBE) for the climatic conditions of Multan. Heat stress is investigated as a function of poultry weight. Thermal comfort of the poultry birds is calculated in terms of temperature-humidity index (THI) corresponding to the ambient and output conditions. The heat production from the poultry birds is calculated using the Pederson model (available in the literature) at various temperatures. The results indicate a maximum temperature gradient of 10.2 °C (MEC system), 9 °C (DEC system), and 6.5 °C (IEC systems) is achieved. However, in the monsoon/rainfall season, the performance of the EC systems is significantly reduced due to higher relative humidity in ambient air.

scholarly journals Thermal Comfort Improvement for Atrium Building with Double-Skin Skylight in the Mediterranean Climate

2020 ◽  
Vol 12 (6) ◽  
pp. 2253
Author(s):  
Refaa Sokkar ◽  
Halil Z. Alibaba
Keyword(s):  
Thermal Comfort ◽  
Thermal Performance ◽  
Mediterranean Climate ◽  
Working Hours ◽  
Economic Benefits ◽  
Climatic Conditions ◽  
Design Strategies ◽  
Double Skin ◽  
The Mediterranean ◽  
American Society

Atria are added to buildings for their aesthetical, environmental, and economic benefits; the appropriate atrium design can enhance an atrium’s thermal performance and the adjacent spaces’ temperatures. However, inappropriate design decisions cause thermal discomfort and consequently, higher energy consumption. Since the Mediterranean climate has diverse climatic conditions around the year, a central atrium with a top-lit skylight is recommended, but during the summer period it can cause overheating, and the insertion of shading elements shrinks the lighting performance: thus, the atrium skylight design is supposed to improve thermal comfort without affecting the lighting level. This study investigated the improvement of thermal performance in the atrium building by the implementation of a double-skin skylight (DSS) to enhance the atrium thermal performance without shading. The research conducted computer simulations with Environmental Design Solutions (EDSL) Tas software sequentially. The study prepared various design strategies, and different proposals were tested and compared in terms of indoor temperatures, with reference to American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE-55). The implementation of DSS achieved an average of 77% comfort in working hours around the year with different opening percentages according to the outdoor conditions. Moreover, results show that changing the DSS glazing materials did not affect the thermal performance of the atrium.

scholarly journals Evaporative Cooling Options for Building Air-Conditioning: A Comprehensive Study for Climatic Conditions of Multan (Pakistan)

Energies ◽  
2020 ◽  
Vol 13 (12) ◽  
pp. 3061 ◽  
Author(s):  
Shazia Noor ◽  
Hadeed Ashraf ◽  
Muhammad Sultan ◽  
Zahid Mahmood Khan
Keyword(s):  
Thermal Comfort ◽  
Co2 Emissions ◽  
Air Conditioning ◽  
Evaporative Cooling ◽  
Cooling Capacity ◽  
Climatic Conditions ◽  
Maximum Temperature ◽  
Human Thermal Comfort ◽  
Work Input ◽  
System Configurations

This study provides comprehensive details of evaporative cooling options for building air-conditioning (AC) in Multan (Pakistan). Standalone evaporative cooling and standalone vapor compression AC (VCAC) systems are commonly used in Pakistan. Therefore, seven AC system configurations comprising of direct evaporative cooling (DEC), indirect evaporative cooling (IEC), VCAC, and their possible combinations, are explored for the climatic conditions of Multan. The study aims to explore the optimum AC system configuration for the building AC from the viewpoints of cooling capacity, system performance, energy consumption, and CO2 emissions. A simulation model was designed in DesignBuilder and simulated using EnergyPlus in order to optimize the applicability of the proposed systems. The standalone VCAC and hybrid IEC-VCAC & IEC-DEC-VCAC system configurations could achieve the desired human thermal comfort. The standalone DEC resulted in a maximum COP of 4.5, whereas, it was 2.1 in case of the hybrid IEC-DEC-VCAC system. The hybrid IEC-DEC-VCAC system achieved maximum temperature gradient (21 °C) and relatively less CO2 emissions as compared to standalone VCAC. In addition, it provided maximum cooling capacity (184 kW for work input of 100 kW), which is 85% higher than the standalone DEC system. Furthermore, it achieved neutral to slightly cool human thermal comfort i.e., 0 to −1 predicted mean vote and 30% of predicted percentage dissatisfied. Thus, the study concludes the hybrid IEC-DEC-VCAC as an optimum configuration for building AC in Multan.

scholarly journals Assessment of thermal comfort indices in an open air-conditioned stadium in hot and arid environment

2021 ◽  
Vol 40 ◽  
pp. 102378
Author(s):  
Saud Ghani ◽  
Ahmed Osama Mahgoub ◽  
Foteini Bakochristou ◽  
Esmail A. ElBialy
Keyword(s):  
Thermal Comfort ◽  
Arid Environment ◽  
Comfort Indices

scholarly journals Barriers on Establishing Passive Strategies in Office Spaces: A Case Study in a Historic University Building

2021 ◽  
Vol 13 (8) ◽  
pp. 4563
Author(s):  
Nuno Baía Baía Saraiva ◽  
Luisa Dias Dias Pereira ◽  
Adélio Rodrigues Gaspar ◽  
José Joaquim da Costa
Keyword(s):  
Thermal Comfort ◽  
Indoor Environment ◽  
Hvac Systems ◽  
Heritage Buildings ◽  
Full Capacity ◽  
Free Cooling ◽  
Passive Strategies ◽  
The University ◽  
Indoor Conditions

The adaptation of spaces to different usage typologies can be complex in heritage buildings. Facilities were initially planned for a specific type of use that, when changed, require additional measures to ensure a suitable indoor environment. Passive strategies—e.g., free cooling—are commonly used as an alternative without requiring equipment installation. However, its implementation often leads to unsatisfactory conditions. Therefore, it is important to clarify the main barriers to achieving thermal comfort in readapted historic buildings. The present work investigates the thermal comfort conditions reported by workers in office spaces of a historic building in the University of Coimbra. A monitoring campaign was carried out between May and September 2020 to assess indoor conditions’ quality. Due to the current pandemic of COVID-19, offices were not occupied at full capacity. A one-day evaluation of thermal comfort was made using a climate analyzer and six occupants were surveyed on 19 August 2020. The main results highlighted discomfort due to overheating of spaces. The causes were related to the combination of inadequate implementation of the free cooling actions and the building use. Furthermore, it was recommended the installation of HVAC systems in case of full capacity.

EVALUATING THE EFFICIENCY OF FEEDING BROILER CHICKENS OF THE ARBOR ACRES CROSS IN HOT CLIMATIC CONDITIONS OF THE REPUBLIC OF CHAD

2020 ◽  
pp. 72-82
Author(s):  
M.V. LAZKO ◽  
◽  
ADAM A. ABDERAKHIM
Keyword(s):  
Environmental Factors ◽  
Biochemical Parameters ◽  
Broiler Chickens ◽  
Central Africa ◽  
Live Weight ◽  
Climatic Conditions ◽  
Geochemical Conditions ◽  
Blood Biochemical ◽  
The Republic ◽  
The University

The paper presents the results of evaluating the efficiency of feed rations offered to broilers of the Arbor Acres cross, formed taking into account the climatic, geochemical conditions of Central Africa and its native food flora. The study was conducted on the basis of an experimental farm at the University of N’Djamena, the Republic of Chad. In the experiment, the authors used five formulas of feed rations, which are currently used by farms in the Republic of Chad for growing broiler chickens. They mainly contain locally availble ingredients. To increase the resistance of the poultry organism to unfavorable environmental factors, the chickens of the control and experimental groups were given “TETRACOLIVIT” and “AMIN’TOTAL” vitamins. The efficiency of feed rations was evaluated by determining the age dynamics of live weight, average weekly gains in live weight and blood biochemical parameters of broiler chickens of the Arbor Acres cross from 1 to 42 days of life. The formula of feed ration No. 1 proved to be the most effective in terms of the cross productivity.

scholarly journals The influence of the climatology of the semi-arid from Alagoas-Brazil on the raw milk microbiota

2017 ◽  
Vol 3 (1) ◽  
pp. 27
Author(s):  
Ticiano Gomes do Nascimento ◽  
Euridice Farias Falcão ◽  
Maria Cristina Delgado da Silva ◽  
Josicleide Nascimento Oliveira Silvino ◽  
Pierre Barnabé Escodro ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Thermal Comfort ◽  
Vegetation Index ◽  
Raw Milk ◽  
Climatic Conditions ◽  
The State ◽  
Maximum Temperature ◽  
Climatic Data ◽  
Microbiological Analysis ◽  
Semi Arid

This study aimed to evaluate the influence of the climatology of the semi-arid from Alagoas-Brazil on the raw milk microbiota in semi-arid area of the 07 micro-regions of the State of Alagoas of Alagoas, Brazil. The climatic data were extracted from National Institute of Meteorology from the Brazilian government. The raw milk was collected after the dairy cow milking process in 12 small rural associations of the semi-arid from the State of Alagoas, during the 4 seasons and the raw milk was carried out procedures of sampling, transportation and microbiological analysis. A total of 58 samples were counted coliforms at 45°C, <em>Escherichia coli</em> and coagulase-positive <em>Staphylococcus</em>. Only 02 rural associations presented low levels of microbiological contamination, which were located in areas of climatic conditions and parameters of thermal comfort index and vegetation index favorable, but 10 rural associations presented high counting of coliforms at 45°C, <em>Escherichia coli</em>. The climatologic parameters (maximum temperature, atmospheric pressure), bovine comfort thermal index and vegetation index have showed to influence the growth of the coliforms at 45°C and <em>Escherichia coli</em> with high incidence during the summer weather. The precipitation parameter, bovine thermal comfort and vegetation index have displayed to influence coagulase-positive<em> Staphylococcus</em> counting especially during the period between the summer end and the autumn beginning seasons. New Actions, and Rural Education and Health Programs should be implemented as politics of Food Safety. New strategies and programs for dissemination more effective on the risks of transmission of pathogens and Foodborne Diseases are necessary as the part of emergence politics of the health and education areas. Regulatory Actions should be encouraged within the processes that improve the quality control of raw milk as well its bioproducts, with professional assistance relevant in agriculture area.

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