Fig. 1: Basic principle of evaporating cooling 
Evaporative pads were made from different materials such as Aspen , metal [8–10], cement , ceramic materials , coconut coirs [8,10,12–14], wood wool fibers [10,12,15], jute fiber [8,16], date palm fibers , khus fibers [4,9,10,15], cellulose paper pad [12,18], plastic , and glass. Cellulose pads are mainly superior these days for their light weight, low cost, and high saturation efficiency, typically, greater than 80 % . They have an excellent coolingefficiency, but they also increase the humidity. So, this increased humidity is the major problem today in case of these direct evaporative coolers. Besides, manufacturing of commercial pads made of these materials are complicated and costly. Aspen pad also is widely used, but it very sensitive to algae infestation that could lead to decay and compaction, which makes it difficult to maintain its efficiency without frequent and costly pad replacement . Therefore, evaluating the locally available cheap materials for use as pads, particularly in rural agricultural areas is essential.
Abstract— The concept of evaporativecooling to provide comfort to human beings in a building is not new and has been used in different parts of a world by using different ways and materials. Vapour compression refrigeration system and Air-conditioning using gases like CFCs and HFCs reduces the utility of evaporativecooling though they have capacity of ozone layer depletion. So many manufacturers have come with different shaped evaporative coolers and different types of padmaterials. In this work new evaporative cooler is designed which is semi-circular in shape instead of rectangular shape (normally used now a days) and the comparison between rectangular shaped cooler and new designed semi-circular shaped cooler is made with Khus as a coolingpad material in terms of temperature drop, humidity rise and coolingefficiency. By using Semi-circular shaped utilisation of water increases, more volume of air comes in contact due to stream line pattern, require less coolingpad material and become compact, thus required less space for installation The newly designed evaporative cooler is consists of two tanks which are perfectly insulated to reduce heat transfer from water and is also incorporated with flow control valve to reduce water consumption and effect of dust mites. The result obtained shows that temperature drop in semi-circular shaped cooler is 5.80C as compared to 3.90C in rectangular shaped and also in rectangular shaped cooler humidity rise is more as compared to semi-circular shaped. The coolingefficiency is improved up to 20.43 % with new design. Also the cost of newly designed Semi-circular shaped cooler is less than rectangular shaped cooler.As well as performance of different coolingpadmaterials like Celdek, Khus, Coconut coir and Bamboo fiber (new material) is analyzed
comfort to human beings in a building is not new and has been used in different parts of a world by using different ways and materials. Vapour compression refrigeration system and Air- conditioning using gases like CFCs and HFCs reduces the utility of evaporativecooling though they have capacity of ozone layer depletion. So many manufacturers have come with different shaped evaporative coolers and different types of padmaterials. In this work new evaporative cooler is designed which is semi-circular in shape instead of rectangular shape (normally used now a days) and the comparison between rectangular shaped cooler and new designed semi-circular shaped cooler is made with Khus as a coolingpad material in terms of temperature drop, humidity rise and coolingefficiency. By using Semi-circular shaped utilization of water increases, more volume of air comes in contact due to steam line pattern, requires less coolingpad material and become compact, thus requires less space for installation. As well as performance of different coolingpadmaterials like Celdek, Khus, Coconut coir and Bamboo fiber (new material) is analyzed in terms of temperature drop, humidity rise and coolingefficiency by using normal water and chilled water with newly designed semi-circular shaped cooler. Also best coolingpadmaterials in terms of human comfort and finally best coolingpadmaterials according to climate of Bhopal is analyzed in this work. With respect to human comfort Celdek is a best material followed by Coconut, Bamboo fiber and Khus. As per weather data of Bhopal, the climate of Bhopal in summer is hot and dry so best material recommended for the evaporativecooling in the climate of Bhopal is Celdek.
Figure 12 shows the effect of the water flow rate on the saturation efficiency. The saturation efficiency increased with an increase in the water flow rate, which was obvious because a low water flow rate would leave a dry spot where unsaturated air could pass directly through the pad without evaporating water, thus increasing the storage chamber temperature and reducing the efficiency. The water may be inadequate to wet and saturate the pad. As the water flow rate increases, the pad becomes wet and closer to being saturated, i.e., the air evaporated more water from the pad and, therefore, more cooling occurred. The value of the saturation efficiency was observed to decline slightly after a water flow rate of 2 L/min, because at this flow rate the pad was excessively wet with water. The excess water may block the pore spaces within the pad fibres, thereby impeding the free flow of air through the pad which reduced good evaporation.
Efforts can be with modification in coolingpadsystem so that its use can be extended for longer period in cooling process Controlled cooling environment can be maintained in the cabinet and its effect can be analyzed to improve the effectiveness. Evaporativecooling is environment friendly and more efficient air cooling method. The efficiency of evaporativecooling systems increases with an increase in temperature and decrease in humidity. Therefore in hot and dry climates, evaporativecooling can save a large amount of energy used for conventional air conditioning systems. Direct evaporative cooler (DEC) uses a wetted pad with large air water contact surface area through which air is passed at uniform rate to make it saturated. However this process is accompanied by an increase in humidity which is sometimes not desirable. Thus, it is seen that variety of materials that can be used as cooling media in direct evaporative cooler is very large. Hence there is need to analyze the performance of alternative materials in terms of saturation efficiency and cooling capacity. Further, the performance of a cooler using hemp and abaca as cooling media has not been analyzed. Hence the attempt is made to fabricate and analyze the performance of such cooler in the present work.
Harby and et al.  reviewed used of evaporative condenser in residential cooling systems. According to them power consumption in coolingsystem with air cooled condenser can be reduced up to 58% and the COP can be improved by about 113.4%. Yu and Chan  found that mist pre-cooling results in to improvement in COP of chiller irrespective of chiller operated under HPC or CTC in hot and dry regions where humidity is below 50%. They have also carried out annual energy analysis and found that CTC with mist pre-cooling could achieve a 19.84% reduction in the annual electricity consumption of the system. Ibrahim et al. shown that pre-cooling the air by about 4 °C before entering the condenser lowers the compressor discharge pressure. The decrease in the discharge pressure resulted in the decrease in compressor power consumption by 6.1% and the cooling effect of the system is enhanced. The combined effect of the increase in the cooling effect and decrease in compressor power resulted in an increase in the coefficient of performance (COP) by about 21.4% and second law efficiency of the system by about 20.5%.
2 INTERNATIONAL JOURNAL OF EMERGING TECHNOLOGY AND ADVANCED ENGINEERING “Design Optimization and Installation of the Evaporative Cooler.”, Md. Almostasim Mahmud, Dr. Md. Alamgir Hossain, M.A.Muktadir : This Evaporativecooling is an environmentally friendly air coolingsystem that operates using induced processes of heat and mass transfer, where water and air are the working fluids. It consists, specifically, in water evaporation, induced by the passage of an air flow, thus decreasing the air temperature. In Bangladesh, Evaporative cooler is already being used in different industries that is imported from varies countries. But most of the cases these are not efficient due to installation error & lack of adjustment with climate change over the year. Initially this paper presents the construction of an evaporative cooler using a test bench of cooling tower for the air flow and water supply facility where local materials were used as evaporativepad. Afterwards; it presents installation in different situation & adjustment of the cooling units with the climate. It concludes that under proper installation, evaporativecoolingsystem is very cost effective & has a very large potential to propitiate thermal comfort and can still be used as an alternative to conventional systems in regions where the design wet bulb temperature is low.
A solar powered evaporativecoolingsystem of 0.6 m 3 capacity was designed and constructed to increase the shelf life of stored vegetables. The evaporative cooler was tested and evaluated using tomato (Roma). The equipment operates on the principle of evaporativecooling and increasing the relative humidity (RH) in the preservation chamber. The storage system was made up of aluminum sheets of 1mm thick while a side of the system is made of jute pad which get moist by water flowing through a series of perforated pipe from the reservoir located at the top of the storage system. The water flows with the influence of gravity. The RH and weight loss of tomato was statistically analyzed using student T – test and the result revealed that there was significant difference in using the evaporativecoolingsystem for storing tomatoes as compared to ambient condition. The average coolingefficiency was found to be 83%. The temperature in the system dropped drastically when compared to the ambient condition which ranges from 6 to 10°C and the relative humidity in the cooling chamber increased considerably to 85%. However, the testing of the evaporativecoolingsystem shows that the tomatoes can be stored for an average of five (5) days with negligible changes in weight, color, firmness and rotting as compared to ambient condition which started rotting after three (3) days. Hence, it is on this note that farmers, house holders and tomatoes processing factories should adopt the use such evaporativecoolingsystem for the storing of fresh tomatoes as this increases the shelf life of tomatoes.
significant in between 8 am and 1 pm. The saturation efficiency was dependent on coolingpadmaterials; highest saturation efficiency was given by sliced wood pads while straw pads gave the lowest. Lo´pez et al. (2012) investigated the characteristic of air flow by using sonic anemometry for two distinct greenhouses with evaporativecooling systems. They selected a greenhouse equipped with a fan-padcoolingsystem and a low-pressure water/air fog cooled greenhouse for the study. It was found that the pad-fan system with shading screen was able to maintain more suitable conditions than the fog system. They found that in an empty greenhouse fan-padsystem reduced the inner air temperature by 11.6ºC lower than the naturally ventilated one while fog system reduced the temperature up to 10.4ºC. Alghannam (2012) conducted several studies to determine the efficiency of several control systems incorporated in a pad-fan cooled greenhouse. He carried out five different tests, Proportional Controller Test (P), Proportional- Integral Controller Test (PI), Proportional Derivative Controller Test (PD), Proportional Integral Derivative Controller Test (PID) and Fuzzy Logic Controller (FLC). All the tests were accomplished to cool the greenhouse from 40°C to 25°C in the extreme summer conditions. He had compared the five control systems theoretically and experimentally. To check the temperature gradient along the length of a conventional fan-pad greenhouse, Misra and Ghosh (2013) proposed longitudinally placed pads with ridge ventilated system. In their greenhouse system, the induced draught fans were fitted at the top of the roof, while the cooling pads were fitted on the sidewalls, as shown in Figure 3. They established a thermal model to predict the inner temperatures considering the energy balance of the greenhouse components. The model results had been validated with a contemporary literature. They reported that temperature in the plantation zone was decreased by 5ºC-7ºC below the ambient temperature providing 1.2 ACM ventilation rate and 50% canopy shading during summer in Kolkata.
In this research, the focus will be mainly on comparing the data collected between three types of material fabrics, sponge and corrugated cellulose to determine suitable material to use as a coolingpad for poultry house. To get the coolingefficiency there are several parameters that need to be measured which is the temperatures and humidity of the air inside and the outside the poultry house by using a temperature and humidity meter.
Figure 8: Radiator cooling fan.
1.8. Water Pump :
The water pump is a simple centrifugal pump driven by a belt connected to the crankshaft of the engine. The pump circulates fluid whenever the engine is running. The water pump uses centrifugal force to send fluid to the outside while it spins, causing fluid to be drawn from the center continuously. The inlet to the pump is located near the center so that fluid returning from the radiator hits the pump vanes. The pump vanes fling the fluid to the outside of the pump, where it can enter the engine. The fluid leaving the pump flows first through the engine block and cylinder head, then into the radiator and finally back to the pump.
Water pump inlet restriction must be kept to a minimum to prevent cavitation. This means radiators, auxiliary oil coolers located between the radiator and the pump inlet (not preferred location), as well as the associated plumbing must introduce minimal restriction. Lines connected to the water pump inlet must have at least the same area as the pump inlet. Bends should be kept to a minimum and they should have a generous radius (no mitered bends). The water pump inlet pressure (suction) must not exceed allowable limits The actual limits is listed in the “Technical Data” section of this manual (refer to section 14). The lowest pressure in the entire coolingsystem is found at the water pump inlet. This pressure can be below atmospheric; thus cavitation (boiling) will occur below 100 C (212 F) at sea level. Altitude causes higher probability of cavitation in cooling systems.
The water supply system was transformed base on the original wet pad. Some new parts were added. For example, water plate, water chute, guide pulley and small pulley (Figure 5). When the multistage regulation system works, the wet pad opens the different cooling level based on the target temperature. With water plate moving along the axial displacement, wet area could be divided into four grades. The water plate can control watered area of pad. So four degrees of watered area can be achieved as 1/8, 1/4, 1/2, and the full of pad area, and then gradual cooling could be achieved. 3.3. The Cooling Effect of Multistage Regulation
In addition to this overcooling can have negative effects on the system. Overcooling can reduce the system performance and shorten the systems service life. Cooling systems are used to manage systems heat. Cooling systems must be properly designed, operated and maintained for proper engine operation and service life. HISTORY:
注： A、A 1 、 A 2 、 B、B 1 、 B 2 、 C、C 1 、 C 2 分别为室内风速测点； D、H 为室内温度、相对湿度及水平方向太阳辐射测点；E 为正压湿帘冷风机出风温度、相对湿度测点；
F 为正压湿帘冷风机进风（室外空气）温度、相对湿度测点；G 为正压湿帘冷风机循环水温测点。
Note: A, A 1 , A 2 , B, B 1 , B 2 , C, C 1 , C 2 are indoor wind velocity measurement points; D, H are indoor air temperature, relative humidity and horizontal solar radiation measurement
points; E is outlet air temperature and relative humidity measurement points of the positive pressure fan-padcoolingsystem; F is temperature and relative humidity measurement points of positive pressure fan-padcoolingsystem inlet air (outdoor air); G is circling water temperature measurement point of the positive pressure fan-padcoolingsystem.
DriSteem's high-pressure fan-assisted dispersion Model FA is a component of a high-pressure atomization system. The fan is designed to throw small water droplets and increase air movement. The Model FA-2 is designed for low ceiling heights. Models FA-3 and FA-4 are designed to pull air from above the fan (typically the hottest air), which promotes better absorption, and throws moisture horizontally. The Model FA can be used for cooling or humidification applications.
Comfort vs. Cost
Comparisons of comfort and cost are based on the ASHRAE comfort zone and a life-cycle cost analysis. There is another more subjective basis for this comparison that can be made as well. Perceptions of comfort can vary widely with age, gender, clothing, culture and expectations based on previous experience with comfort systems. It is easy to understand how a person who has always worked in a hot unconditioned environment will perceive even a ventilating fan as relative comfort. People who were raised in parts of the country where evaporativecooling cannot be used effectively will be accustomed to feeling comfortable in a refrigerated environment. A person from a humid environment will say that their skin is cracking in the dry southwest, and that refrigerated air conditioning makes them feel drier, whereas the evaporatively cooled environment feels “more alive”. Individuals with acute sensitivities to indoor air pollutants will equate comfort with the absence of symptoms such as nasal stuffiness or irritation, dry, itchy, or burning eyes, lethargy, headaches, and exacerbation of disorders such as asthma, eczema and sinusitis. Factors such as these are not reflected in the graphical boundaries on a psychrometric chart.
high atmospheric stability. Figure Z-5 shows the few, discrete receptors that have the potential for ground-level fog under those conditions. None are located along the runway for the Portland-Troutdale Airport, at the Federal Express facility, or along I-84. Of the few receptors modeled as having the potential to experience ground-level fog, the results indicate that none would experience fog for more than 8 hours per year. As shown in Figure Z-6, even fewer receptors have the potential for occurrence of ground-level ice formation. None of those receptors are located along the Portland-Troutdale Airport runway, at the Federal Express facility, or along I-84. The few, discrete receptors modeled as having the potential for surface-level ice formation are located within or immediately adjacent to the Facility site boundary and northwest of the Facility, across the Columbia River, in an area of Washington away from major roadways, airports or other features where ice formation would be expected to cause a significant adverse impact. Of those receptors, the results indicate that none of the near-field receptors would experience icing for more than 8 hours per year and the receptors northwest of the facility, across the Columbia River, would only experience icing 1 hour or less per year. The model results thus demonstrate that the Facility’s cooling towers will not cause more than de minimis impacts from ground-level fogging or ice formation. (C) The predicted locations and rates of deposition of solids released from the cooling tower (cooling
2.1. Direct evaporativecooling (DEC)
The working principle scheme of the DEC equipment and a simplified flow scheme are presented in figure 1. The warm inlet air (1) enters in a pad which is sprayed with water at the wet bulb (WB) temperature of the inlet air. The heat transfer is realised from the warm air to the cold water. The heat is transferred by the air stream as sensible heat and is absorbed by the water as latent heat. Corresponding to the value of latent heat, a part of the water is evaporated being embedded by diffusion into the flowing air, increasing the moisture content of this air. The temperature of the outlet air (2) decreases due to the sensible heat transferred by the air, but the enthalpy of the outlet air will be the same with the enthalpy of inlet air as effect of the latent heat recovered into the air as moisture.
increased by reducing the compressor work or by increasing the refrigeration effect. It was found through the literature that advancement in the design of compressor reduce the compressor work and also the advancement in the capillary tube increased the refrigerating effect. Modifications in condenser are meant to increase degree of sub-cooling of refrigerant which in turn increases refrigerating effect. The improvement in coefficient of performance and reduction of energy consumption of a window air conditioning system when retrofitted with ducts and evaporativecooling in the condenser of Window air conditioner is reviewed in the study. The condensing unit is fitted with evaporative air cooling unit. This condenser can exchange heat with the ambient air, cooled with evaporativecooling which is much lower in temperature than atmospheric air. By application of evaporative air cooling it is possible to ex-change more heat. A Window air conditioner is introduced by putting evaporative air cooler which includes the cooling pads system and injecting water on them in order to cool down the air before it passes over the condense. This paper presents the concept of effect of Under- cooling on the Coefficient of Performance of Vapor Compression Refrigeration System mainly carried out to improve the coefficient of performance of system.