scholarly journals Experiments on Energy-Efficient Evaporative Cooling Systems for Poultry Farm Application in Multan (Pakistan)

2021 ◽  
Vol 13 (5) ◽  
pp. 2836
Author(s):  
Khawar Shahzad ◽  
Muhammad Sultan ◽  
Muhammad Bilal ◽  
Hadeed Ashraf ◽  
Muhammad Farooq ◽  
...  
Keyword(s):  
Heat Stress ◽  
Low Cost ◽  
Evaporative Cooling ◽  
Thermal Exposure ◽  
Climatic Conditions ◽  
The Body ◽  
Dew Point ◽  
Sweat Glands ◽  
Cooling Systems ◽  
Humidity Index

Poultry are one of the most vulnerable species of its kind once the temperature-humidity nexus is explored. This is so because the broilers lack sweat glands as compared to humans and undergo panting process to mitigate their latent heat (moisture produced in the body) in the air. As a result, moisture production inside poultry house needs to be maintained to avoid any serious health and welfare complications. Several strategies such as compressor-based air-conditioning systems have been implemented worldwide to attenuate the heat stress in poultry, but these are not economical. Therefore, this study focuses on the development of low-cost and environmentally friendly improved evaporative cooling systems (DEC, IEC, MEC) from the viewpoint of heat stress in poultry houses. Thermodynamic analysis of these systems was carried out for the climatic conditions of Multan, Pakistan. The results appreciably controlled the environmental conditions which showed that for the months of April, May, and June, the decrease in temperature by direct evaporative cooling (DEC), indirect evaporative cooling (IEC), and Maisotsenko-Cycle evaporative cooling (MEC) systems is 7–10 °C, 5–6.5 °C, and 9.5–12 °C, respectively. In case of July, August, and September, the decrease in temperature by DEC, IEC, and MEC systems is 5.5–7 °C, 3.5–4.5 °C, and 7–7.5 °C, respectively. In addition, drop in temperature-humidity index (THI) values by DEC, IEC, and MEC is 3.5–9 °C, 3–7 °C, and 5.5–10 °C, respectively for all months. Optimum temperature and relative humidity conditions are determined for poultry birds and thereby, systems’ performance is thermodynamically evaluated for poultry farms from the viewpoint of THI, temperature-humidity-velocity index (THVI), and thermal exposure time (ET). From the analysis, it is concluded that MEC system performed relatively better than others due to its ability of dew-point cooling and achieved THI threshold limit with reasonable temperature and humidity indexes.

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 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.

Extending the shelf-life of vegetables using low cost evaporative cooling systems in Mali

2020 ◽  
pp. 419-426
Author(s):  
W. Bihon ◽  
A. Coulibaly ◽  
T. Chagomoka ◽  
O. Sanogo ◽  
F. Cisse ◽  
...  
Keyword(s):  
Shelf Life ◽  
Low Cost ◽  
Evaporative Cooling ◽  
Cooling Systems

scholarly journals Beat the heat: Culex quinquefasciatus regulates its body temperature during blood-feeding

2020 ◽  
Author(s):  
Joanna M. Reinhold ◽  
Ryan Shaw ◽  
Chloé Lahondère
Keyword(s):  
Heat Stress ◽  
Body Temperature ◽  
Culex Quinquefasciatus ◽  
Evaporative Cooling ◽  
Blood Feeding ◽  
The Body ◽  
List Type ◽  
Physiological Level ◽  
Wide Range ◽  
Warm Blood

AbstractMosquitoes are regarded as one of the most dangerous animals on earth. As they are responsible for the spread of a wide range of both human and animal diseases, research of the underlying mechanisms of their feeding behavior and physiology is critical. Among disease vector mosquitoes, Culex quinquefasciatus, which is a known carrier of West Nile virus and Western Equine Encephalitis, remains relatively understudied. As blood sucking insects, adaptations (either at the molecular or physiological level) while feeding on warm blood is crucial to their survival, as overheating can result in death due to heat stress. Our research aims to study how Cx. quinquefasciatus copes with heat associated with the ingestion of a warm blood-meal and to possibly uncover the adaptations this species uses to avoid thermal stress. Through the use of thermographic imaging, we analyzed the body temperature of Cx. quinquefasciatus while blood feeding. Infrared thermography has allowed us to identify a cooling strategy, evaporative cooling via the production of fluid droplets, and an overall low body temperature in comparison to the blood temperature during feeding. Understanding Cx. quinquefasciatus’ adaptations and various strategies that they employ to reduce their body temperature while blood-feeding constitutes the first step towards the discovery of potential targets of opportunity for their control.HighlightsMosquitoes have evolved to cope with heat stress associated with warm blood ingestionCulex quinquefasciatus displays heterothermy while blood-feedingThe abdominal temperature decreases due to evaporative cooling using urine dropletsOverall, the mosquito body temperature is much cooler than the ingested blood

scholarly journals Effect of age at first calving and heat stress at parturition on reproductive efficiency and postpartum disorders in Holstein heifers

2019 ◽  
Vol 17 (2) ◽  
pp. e0405
Author(s):  
Miguel Mellado ◽  
Vanessa Alba ◽  
Leticia Gaytán ◽  
José E. García ◽  
Jesús Mellado
Keyword(s):  
Heat Stress ◽  
Age Groups ◽  
Dairy Farm ◽  
Climatic Conditions ◽  
Conception Rate ◽  
Age At First Calving ◽  
Hot Climate ◽  
Postpartum Disorders ◽  
Humidity Index ◽  
The Impact

The objective of this study was to evaluate the impact of age at first calving (AFC) and climatic conditions at calving on peripartum disorders and reproductive performance in Holstein heifers in a hot environment. A total of 3000 reproductive records from a large highly technified dairy farm were used; the variables evaluated were temperature humidity index (THI; <77, 77-83, >83) at calving and AFC (<2.0, 2.0-2.2 and >2.2 years). Across age groups, the cases of dystocic parturition increased (p<0.05) when the deliveries occurred with severe heat stress (4.3% vs. 3.3% for THI >83 and <83 units, respectively). Across THI, conception rate at the first postpartum artificial insemination (AI) was lower (p=0.02) for heifers calving for the first time >2.2 years compared to heifers calving between 2.0 and 2.2 and <2.0 years (9.8, 15.3 and 13.7%, respectively). Conception rate at first AI postcalving was higher (p<0.01) in heifers calving with THI less than 83 units than in heifers calving with a THI >83 units (16.8 vs. 5.4%). The conception rate considering all services was affected (p<0.05) by AFC (42.7, 50.4 and 40.9% for AFC <2.0, 2.0-2.2 and >2.2 years, respectively). The interaction AFC × THI at calving was significant (p<0.05). The occurrence of metritis was higher (p<0.05) in heifers <2.0 years of age at calving than those calving after 2 years of age. The presence of ovarian cysts was less common (p<0.05) in heifers with greater AFC. In conclusion, increasing the AFC in Holstein heifers had no benefits in reproduction and health, compared with heifers calving at <2.0 years. These data in a hot climate suggest that heifers should be selected to begin their first lactation before 2 years of age.

scholarly journals What is the best temperature-humidity index equation to indicate heat stress in crossbred dairy calves in a tropical environment?

2019 ◽  
Vol 49 (1) ◽  
Author(s):  
Fernanda Gatti de Oliveira Nascimento ◽  
Hellen Cris Pinto Aguiar ◽  
Gustavo Moya Rodrigues ◽  
Ednaldo Carvalho Guimarães ◽  
Mara Regina Bueno de Mattos Nascimento
Keyword(s):  
Heat Stress ◽  
Dew Point ◽  
Tropical Environment ◽  
Dairy Calves ◽  
Sensible Heat ◽  
Dew Point Temperature ◽  
Physiological Variables ◽  
Temperature Humidity Index ◽  
Humidity Index ◽  
The One

ABSTRACT: The aim of this study was to determine among nine temperature-humidity index (THI) equations, the one that best represents the effects of heat stress on crossbred dairy calves reared in a tropical environment. Twelve male and female calves, aged 20 to 60 days, and raised in a tropical pen were evaluated. Respiratory (RR) and heart rates (HR), rectal (RT), body surface (BST), dry bulb (Tdb) and wet bulb (Tbw) temperatures, partial vapor pressure (Pv), relative humidity (RH) and dew point temperature (Tpo) were quantified in the morning and afternoon. Nine THI equations were calculated. The highest correlation between physiological variables and this was used to select the best THI equation. Averages for nine THI equations, Tdb, Twb, Pv, Tdp, RR, HR, RT, and BST were higher in the afternoon than in the morning, whereas that for RH was the opposite. The highest values for RT occurred at temperatures above 26.4°C and when humidity was below 55.5%. The Tdb and Pv correlations with RR (0.697 and 0.707), RT (0.703 and 0.706) and BST (0.818 and 0.817) were significant and positive, whereas the RH correlations with the same physiological variables were significant and negative (-0.622, -0.590 and -0.638, respectively). The best index was the THI sensible heat-based ( T H I = 3.43 + 1.058 x T d b - 0.293 x R H + 0.0164 x T d b x R H + 35.7), which was significantly correlated with RR (r=0.668 and r²=0.446), HR (r=0.259 and r²=0.067), RT (r=0.693 and r²=0.479) and BST (r=0.807 and r²=0.650). In conclusion, the THI sensible heat-based equation best represents the effects of heat stress on crossbred dairy calves reared in a tropical environment.

Heat stress problem in dairy farming

2020 ◽  
pp. 10-11
Author(s):  
Ekaterina N. Rud ◽  
◽  
Elena V. Kuzminova ◽  
Marina P. Semenenko ◽  
Andrey A. Abramov ◽  
...  
Keyword(s):  
Heat Stress ◽  
Negative Impact ◽  
Environmental Parameters ◽  
Animal Husbandry ◽  
The Body ◽  
Environment Analysis ◽  
Temperature And Humidity ◽  
Humidity Index ◽  
Krasnodar Region ◽  
Prolonged Heat

In the context of the industrial survival of animal husbandry, taking into account the climatic characteristics of Krasnodar region, climate is considered as a heat stress, the result of an imbalance between the intake of heat from the environment and its release by the body. To assess the risks of occurrence and severity of heat stress in cattle, it is necessary to take into account not only the ambient temperature, but also humidity indicators. The temperature and humidity index provides for these two variables and allows us to assess the need for cooling of animals. The article provides information on the possibilities of occurrence and impact of heat stress due to the temperature-humidity state of the environment. Analysis of the reporting data of the Veterinary Department of Krasnodar region and the number of industries in Krasnodar region and cattle sampling rates from 2017 to 2019 demonstrates an increase in the number of abortions and youth losses during the third quarter when the temperature of the environment reaches its maximum. With this in mind, to increase the adaptability of animals under prolonged heat stress, it is necessary to regularly monitor the environmental parameters (use of thermometers and hygrometers to assess the temperature and humidity index), as well as plan protective measures (adapted feeding technology, specialized additives, good bulky feed), which will help to minimize the negative impact of hyperthermia on the economy of livestock production.

Development of an Improved Desiccant-Based Evaporative Cooling System for Gas Turbines

2008 ◽  
Author(s):  
Amir Abbas Zadpoor ◽  
Ali Asadi Nikooyan
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Cooling System ◽  
Evaporative Cooling ◽  
Climatic Conditions ◽  
Cooling Systems ◽  
Actual Performance ◽  
Evaporative Cooling System ◽  
Industrial Gas Turbine ◽  
Gas Turbine Cycle

The evaporative inlet cooling systems used for inlet cooling of gas turbines during hot summers do not work well in humid areas. However, desiccant wheels can be used to dehumidify the air before passing it trough the evaporative cooler. Since the desiccant wheels work adiabatically, the resulting air is hotter than the air introduced to the wheel and an evaporative cooling system is used to cool down the dehumidified air. Combined direct and indirect evaporative coolers have been already used to investigate the effects of dehumidification on the effectiveness of the evaporation cooling systems. It is shown that a single desiccant wheel does not offer much higher effectiveness compared to the multiple-stage evaporative systems. In this paper, an improved version of the desiccant inlet cooling system is presented. Additional dehumidification and indirect evaporative cooling stages are added to increase the effectiveness of the inlet cooling. A typical gas turbine cycle along with an industrial gas turbine with actual performance curves are used to simulate the thermal cycle in presence of the different inlet cooling systems. The simulations are carried out for three different climatic conditions. The improved and original desiccant-based systems are compared and it is shown that the added stages substantially improve the effectiveness of the desiccant-based inlet cooling.

scholarly journals Review of Dew Point Evaporative Cooling Technology for Air Conditioning Applications

2021 ◽  
Vol 11 (3) ◽  
pp. 934
Author(s):  
Anna Pacak ◽  
William Worek
Keyword(s):  
Porous Materials ◽  
Water Distribution ◽  
Evaporative Cooling ◽  
Electricity Consumption ◽  
Dew Point ◽  
Coefficient Of Performance ◽  
Cooling Systems ◽  
Climate Conditions ◽  
Current State ◽  
Indirect Evaporative Cooling

Indirect evaporative cooling has the potential to significantly improve the natural environment. It follows from a significant reduction in electricity consumption in the hot period, and hence lower operating costs for cooling systems. This paper presents the current state of knowledge and research directions on dew point indirect evaporative cooling. It was found that researchers focus on the development of dew point indirect evaporative coolers (DPIEC) by improving its design, geometry, water distribution, and new porous materials implementation. To evaluate the performance of new types of DPIEC, different methods are used by the scientists. Finally, optimized devices are studied in terms of their performance in different systems, like hybrid and desiccant systems, considering different climate conditions. Potential directions of development of evaporative technologies were indicated, such as increasing the coefficient of performance of solid desiccant evaporative cooling systems, developing novel geometry, and efficient water distribution, including development of porous materials.

Solar Assisted Desiccant Cooling Simulation for Different Climate Zones

2011 ◽  
Author(s):  
Wendell Concina ◽  
Suresh Sadineni ◽  
Robert Boehm
Keyword(s):  
Air Conditioning ◽  
Cooling System ◽  
Evaporative Cooling ◽  
The United States ◽  
Economic Benefits ◽  
Climatic Conditions ◽  
Hot Water ◽  
Low Grade ◽  
Cooling Systems ◽  
Climate Zones

Evaporative cooling is among the most cost effective methods of air conditioning, but is less efficient in humid climates. An evaporative system coupled with a desiccant wheel can operate effectively in broader climatic conditions. These cooling systems can substitute traditional vapor compression air conditioning systems as they involve environmentally friendly cooling processes with reduced electricity demand (which is commonly generated from fossil fuels) along with no harmful CFC based refrigerant usage. Furthermore, direct utilization of low grade energy sources such as solar thermal energy or flue gas heat can drive the desiccant regeneration process, thus providing economic benefits. This study presents the results of simulations of desiccant cooling system performance for different climate zones of the United States. Solar assisted desiccant air conditioning is particularly useful where there are abundant solar resources with high temperature and humidity levels. Building energy simulations determined cooling energy requirements for the building. Simulation of an evacuated solar hot water collector model provided the heat energy available for regeneration of the desiccant. Solid desiccant of common material such as silica gel used in a rotary wheel is simulated using established validated computer models; this is coupled with evaporative cooling. Transients of the overall system for different cooling loads and solar radiation levels are presented. Finally, feasibility studies of the desiccant cooling systems are presented in comparison with traditional cooling system. Further analysis of the data presents optimization opportunities. Energy savings were achieved in all climatic conditions with decreased effectiveness in more humid conditions.

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