An evaporative cooler also swamp cooler, swamp box, desert cooler and wet air cooler is a device that cools air through the evaporation of water. All evaporative cooler types have one thing in common. Evaporative cooling evaporative cooling is a thermodynamic process in which hot and humid air passes over a wet surface, thus water evaporates due to hot air and latent heat is gained by air at the expense of sensible heat thereby its temperature is reduced. Evaporative cooling systems maintain better air quality and eliminate more allergens than an equivalent ac system. Your evaporative air conditioner has control switches to provide for the benefits of fresh air ventilation and cooling at high and low air flows. It is not only uncomfortable to work in, but it can be downright dangerous for the welfare of your workers.
Evaporative cooling an overview sciencedirect topics. The temperature of dry air can be dropped significantly through the phase transition of liquid water to water vapor, which requires much less energy than. New mexicans are most familiar with direct eacs that are also commonly used for residential cooling. Direct evaporative cooling is an adiabatic process where the dry bulb temperature is lowered without changing the amount of heat idec dec dec idec in the air.
Characteristic and different types of losses generated in cooling tower. The conversion of sensible heat to latent heat causes a decrease in the ambient temperature as water is. In this paper different cooling pads have been studied. Types of evaporative cooling evaporative cooling works by employing waters large. Evaporative cooler types evaporative coolers cool boss. Evaporative coolers external installation down discharge. There are two basic types of evaporative air coolers eacs. There are two broad types of evaporative coolers available on the market, direct and indirect, both commonly known as twostage. Evaporative cooling systems perform more efficiently with reasonable cooling capacities particularly in. The evaporative cooler was tested and evaluated using tomato roma. You can duplicate the principle behind direct evaporative cooling by wrapping a wet handkerchief around your neck on a hot day and standing in front of a fan. The basic structure of the cooling chamber can be built from bricks and river sand, with a cover made from cane or other plant material and sacks or cloth.
The concept and implementation of free cooling dates back millennia, with porous clay vessels full of water placed in rooms, or egyptians and persians using windcatchers, passing the air through subterranean water stores and back into buildings. One must know them to understand the operation of evaporative coolers. It makes use of the free latent energy in the atmosphere. Evaporative cooling market growth, trends and forecast 2020 2025 the market is segmented by type of cooling direct evaporative cooling, indirect evaporative cooling, and twostage evaporative cooling, application residential, commercial, and industrial, distribution channel big box retailers, hvac contractors, and distributors, and region. The concept of watercooling a roof has a long history but it is estimated that less than 60 million square feet. What are the advantages and disadvantages of evaporative. Evaporative cooling are mainly of two types namely direct and indirect evaporative cooling systems as shown in fig. In this paper an approach to recover water from such humid air is presented.
Cooling is provide by evaporative heat exchange which takes advantage of the principles of the latent heat of evaporation where tremendous heat is exchanged when water evaporates. Evaporative cooling is the natural way of cooling, similar to a breeze flowing across a lake. Even though losses are generated in the cooling tower, the cooling is achieved due to heat transfer. Ware houses or garages, and it may also be used outofdoors on portico or on work sites. Background evaporative condensers came into common use for. When warm, dry unsaturated air is pulled through a watersoaked pad, water is evaporated and is absorbed as water vapor into the air. The process is indicated in the psychrometric chart below. The primary responsibility of a business man is to provide the secure and comfortable feeling to the clients who visit their office.
International journal of engineering research and general. Design of compact evaporative cooler to improve cooling. Evaporative cooling is a reliable, lowtech method to provide cooler air during hot weather. In evaporative cooling systems an air stream with high humidity ratio is released in the ambient without any treatment. Experimental and numerical study of a heat pipe based. The principle of evaporative cooling can be used in different ways. It is used in data center and large it facilities to provide air cooling conditioning services. Evaporative cooling can be further classified as follows fig. The greenhouse with sliced wood pads gave the lowest relative humidity 39. The equipment operates on the principle of evaporative cooling and increasing the relative hu midity rh in the preservation chamber.
The air passes straight across the humidifier into the cooling chamber in direct evaporative cooling system, while the. Performance evaluation of three different types of local. Duan, zhiyin 2011 investigation of a novel dew point. This phase change requires energy, which is called latent heat of evaporation this is the energy required to change a substance from liquid phase to the gaseous one without temperature change. Evapco is dedicated to designing and manufacturing the highest quality products for the evaporative cooling and industrial refrigeration markets around the globe. The air temperature is lowered due to its contact with the water and has a relaxing, cooling effect on people. Evaporative cooling guidelines manual quick reference field guide lesson. Cooling through evaporation is the natural occurrence. The theory of direct evaporative cooling owes much to dr. Evaporative cooling is a type of environment cooling techniques that cools the surrounding air using water evaporation technique. However, active and passive cooling strategies have not been adequately examined in a. Review of research and application of evaporative cooling. An experimental analysis of direct evaporative cooler by. An evaporative cooler cools the air by means of the evaporation of water.
A direct evaporative cooling system is the simplest and most popular evaporative cooling system available. Evaporative cooling market growth, trends and forecast. Developments in the evaporative cooling industry have reliably increased the efficiency. Analysis of evaporative cooling system and recovery of. The evaporative cooling module shall be selfcontained. Though they serve exactly the same purpose and uses almost the same mechanism, evaporative air coolers are of different types. In summary, evaporative cooling is the process of removing heat from a surface due to the evaporation of water. It takes heat energy to change the water or any liquid from a liquid into a vapor. Evaporative cooler engineering specification 598 1. Concept of evaporative cooling evaporative cooling is the process by which the temperature of a substance is reduced due to the cooling effect from the evaporation of water.
It will consist of the component parts as listed in the following sections. Evaporative cooling is a heat and mass transfer process that uses water evaporation for air cooling, in which large amount of heat is transferred from air to water, and consequently the. Evaporative cooling practical action 3 any part of the country using locally available materials. Furnish proof satisfactory to the owner or his representative, of. Evaporative cooling is based on the thermodynamics of evaporation of water, i. Portable coolers cool small places or rooms, generally up to 300 square feet. Direct evaporative cooling open circuit direct evaporative cooling introduces water directly into the. The direct evaporative cooling process in a psychrometric chart air at with dry bulb temperature 70 o f and relative moisture 60% state a is cooled down state b by evaporating water. Extreme heat and humidity can, and frequently does, cause heat strokes. As the knowledge of the wonders of air coolers spreads, many are turning towards them as the ultimate solution to their cooling needs in homes, offices, and commercial places like factories and warehouses. Water can absorb a lot of heat without changing phases, allowing it to remove heat. Evaluation of evaporative cooling systems in industrial buildings article pdf available in international journal of heat and technology 333.
On the other hand, the indirect cooling method allows industrial spaces, restaurants or other businesses to cool their spaces to temperatures that are lower than those offered by portable swamp coolers like cool boss. In a direct evaporative cooler, a blower forces air through a permeable and watersoaked pad. Performance evaluation of alternative evaporative cooling. The most common example in human is the process of perspiration. Evaporative cooling design guidelines ced engineering. The results obtained for relative humidity from the greenhouses with different types of evaporative cooling pads, as well as for the conditions outside the greenhouses, at 8 am are shown in table 2 and fig.
Highpressure system first costs are generally higher than other adiabatic systems due, mostly, to the cost of adding. Evaporative cooling differs from typical air conditioning systems, which use vaporcompression or absorption refrigeration cycles. His theory of adiabatic saturation and the standard psychrometric chart are its roots. Experts say that in germany approximately 10% of the roughly 25,000 new hvac systems produced each year are equipped with this environmentally friendly cooling technology, and that this trend is increasing.
Evaporative cooling design guidelines manual iv this report by nrg engineering is funded by the new mexico energy minerals and natural resources department, 1220 south st. During the process of perspiration, it absorbs heat to cool the body. Installing an evaporative cooling system is an alternative method of using an air conditioning system that pumps refrigerant through compression and evaporative cycles. Anyone who has spent some time in a hot, stuffy warehouse understands how torturous heat and humidity can be. Evaporative cooling design guidelines manual iv this report by nrg engineering is funded by the new mexico energy minerals and natural resources department, 1220. The analysis of variance showed that there were significant differences p 0. In central hvac systems, cooling systems based on indirect evaporative cooling are becoming increasingly important. Course contents evaporative coolers, often called swamp coolers, are cooling systems that use only water and a blower to circulate air. Performance evaluation of alternative evaporative cooling media.
How free is evaporative cooling in the data center green. Qatar national research fund a member of qatar foundation. Compared to airconditioning which uses mechanical refrigeration, the operating cost of heat evaporative. Principles and application of evaporative cooling systems. This adiabatic cooling process is also used to create the chilled water that feeds our indirect evaporative cooling coil. In hot humid climates with a high relative humidity, the air becomes fully saturated reducing the effect of evaporative cooling.
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