Two-stage evaporative cooling for improving poultry housing environment in Algerian arid zones (original) (raw)
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Sustainability, 2021
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...
Towards the development of energy-efficient poultry air conditioning system
Academia Letters, 2021
The poultry industry, which plays a significant role in food security, is the fastest-growing agricultural sub-sector, particularly in developing countries. It is believed that factors such as the increase in population, and urbanization will substantially contribute to the growth of the sector in the future. The poultry meat production throughout the world reached 133.3 million tonnes by 2020 but scored the lowest growth rate since 1960, because of disease outbreaks in some European countries [1]. The stipulation of an adequate environment within poultry houses is a critical requirement for the success of the poultry industry, as the thermal environment has a significant impact on the welfare of the birds. The poultry birds are homeothermic and able to persist body temperature within the thermoneutral range of 25.5-37.7℃ [2,3]. High temperature causes a rise in body temperature because of less heat dissipation, thereby create heat stress. Heat stress has significant effects on the birds which are involving less feed intake, more water consumption, panting, an exaltation of wings, decrease growth rate, and increase immunosuppressant as well as mortality [4,5]. Similarly, high humidity causes various fungal diseases including aspergillosis, candidiasis, mycotoxins, dactylariosis, favus, cryptococcosis, rhodotorulosis, and mucormycoses. These fungal diseases produced severe morbidity and mortality particularly in young birds as well as stunted growth and fatal encephalitis [6]. Ideal ranges of temperature and relative humidity within such houses varied between 20-34℃, and 50-70% throughout their growth period [7,8]. In addition, the temperature-humidity index, which can be calculated from both temperature and relative humidity combinations should be less than 30℃ [9]. Conventional practice to maintain such temperature and humidity conditions in poultry houses is pad-type evaporative cooling. The evaporative cooling pads work on the principle
Applied Sciences, 2020
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 condi...
Optimal evaporative cooling system configuration for livestock building
2008
The efficiency of ventilation and evaporative cooling systems usually depend on the system configuration, air distribution and cattle layout. From a thermo-fluid dynamics point of view, local recirculation zones could be present, reducing significantly the advantages of evaporative cooling. Furthermore, while for hot and dry climates such advantages are in general quite evident, in Italy the temperate and moderately humid summers make uncertain the cost-benefits ratio. Previous results show that such systems are convenient even for temperate climates. In order to get an efficient implementation an optimal location of EC panels is required. From this point of view a double target is required: i) to reduce the indoor dry bulb temperature; ii) to keep low the increasing humidity due to the direct evaporative cooling effect.
Poultry environmental control systems need to minimize problems and environmental stress generated by excess heat in the poultry housing to achieve best production and improve production economic benefits. Because it is difficult to control natural ventilation and urban areas outside air is often polluted and cannot be supplied to inner spaces before been filtered, the poultry housing environmental control system needs to provide (using mechanical ventilation integrated with the thermal conditioning unit) adequate ventilation air to remove moisture, gases like ammonia and hydrogen sulphide, disease organisms, and heat using minimum energy waste. Besides the high electrical demand of refrigerant compression thermal conditioning units used by most building environmental control systems, fans used to transport the cool air through the thermal distribution system draw a significant amount of electrical energy in comparison with electrical energy used by the building environmental contro...
2020
Agriculture is an important economic sector for developing countries. It is providing food, fiber and energy to the increasing human population. In developing countries like Pakistan, livestock is the main source of livelihood for majority of the rural population. As compared to research on crop production and the effect of climate on livestock production systems, or how they can adapt to changes is rarely studied. In climate change affected Pakistan, the milk production of foreign breeds is highly affected by the heat stress. The sternness of heat stress conditions in highyielding dairy cows is currently underestimated. The present study investigates the system feasibility and evaluation of temperature-humidity index (THI) for foreign breeds of cattle under interior climatic zone in Multan. To achieve the thermal comfort for high productive breeds of cattle, different types of vapor compression (VCAC) air conditioning system are used worldwide. These systems consume large amount of primary energy and contribute directly to global warming. To overcome this problem, low-cost evaporative cooling system has been studied and designed for thermal comfort of livestock applications and the feasibility of these systems are checked for the climatic condition of Multan. The expected climate changes that can affect the livestock population and milk production was studied in present study and a possible option for long term planning has been discussed.
JP Journal of Heat and Mass Transfer
Poultry is a vital sector for emerging economies like Senegal. Climatic Ousmane Diop et al. 98 conditions during the dry season are not favourable for poultry houses. Conventionally, naturally ventilated poultry houses with transverse or single-sided openings are used to combat heat stress in chickens. Thus, this study aims to analyze the thermal performance of a naturally ventilated poultry house with openings on a single facade in hot and semi-arid climate regions. The ambient parameters such as temperature, relative humidity and air velocity were measured in the poultry house during the hot period from the chickens' third to the fifth week of life. The results show that the interior temperatures in the poultry house vary between 36°C and 42°C at maximum solar irradiance for humidity varying from 11 to 36%. The air velocity in the poultry house below 1.5m/s does not allow the heat accumulated in the poultry house to be evacuated. The temperature-humidity index (THI) of the test day of April 9, 2022 corresponding to the beginning of the fourth week of growth of the chickens ranged from 70 to 93 between 11:00h a.m. and 08:00h p.m., showing discomfort in the poultry house during the day. A mortality of 6.5% was recorded when the THI reaches 93 in the poultry house.
Application of urban passive cooling systems and design techniques in livestock buildings
IOP Conference Series: Earth and Environmental Science, 2020
A protected environment for plant and animal growth is necessary for the increase of agricultural production. The expanding number of agricultural structures with a controlled environment, such as greenhouses and livestock structures, might be the key to tackling the continuously increasing food demand due to the growing population. Farm animals bred inside environmentally controlled buildings are positively affected. It has been found that farm animals have shown dramatic reduction in their productivity resulting in economic losses when the temperature rises beyond the upper critical point of their thermoneutral zone. For this reason, cooling systems and design techniques are developed and used in livestock buildings, in order to keep the optimum growth environmental conditions (temperature and humidity), so as to avoid heat stress. Conventional energy, which is the main energy source consumed by the active cooling systems might not be economically viable and additionally it has negative effects on the environment. Therefore, passive cooling methods towards the sustainability of livestock building designs are being examined, since the viable development of the economic factor is crucial. The most usual passive cooling systems are based on shelters, insulation, natural ventilation as well as architectural parameters, affecting the cooling of a building, such as the roof inclination, the wall colour, the orientation etc. Hybrid systems, such as earth to air heat exchangers are also used. There are some passive cooling solutions that have been used with success in urban buildings and these may be quite effective for livestock buildings without excessive modifications. The present study focuses on a description and evaluation of these solutions in primary food production.