Santamouris 2007 evaporative cooling was used and commercialized in desert coolers since 1920. The other type of eac is called indirect because the evaporative cooling is delivered across a heat exchanger, which keeps the cool moist air separated from the. This method is energy efficient and uses weather from the outdoors to cool the facility at times when it is cooler than the temperature inside. Publications iv publications xudong zhao, zhiyin duan, changhong zhan, 2009, dynamic performance of a novel dew point air conditioning for the uk buildings. Evaporative cooling is a reliable, lowtech method to provide cooler air during hot weather. Anyone who has spent some time in a hot, stuffy warehouse understands how torturous heat and humidity can be. This is a product development visual walkthrough for a d. In the hvac industry, the term cooling tower is used to describe both open and. Principles and application of evaporative cooling systems. Evaporative cooling is based on the thermodynamics of evaporation of water, i. Ca utilities 20 title 24 stakeholder meeting for proposed code changes 3232011 heat recovery for space heating analysis based on full heat recovery. The design will depend on the materials available and the users requirements.
The best time to measure wet bulb temperature to calculate the potential cooling performance of the evaporative cooling system is in the afternoon. Direct evaporative cooling dec keeps the primary product air in direct contact with water, which causes evaporation of the water and so the reduction of. Student 2assistant professor 1,2shri sad vidya mandal institute of technology, bharuch392001, gujarat, india abstractthis paper aims to improve the performance of. Analysis of standards options for evaporative coolers. Water can absorb a lot of heat without changing phases, allowing it to remove heat. Analysis of advanced solar hybrid desiccant cooling systems.
Direct indirect with direct evaporative cooling, outside air is blown through a watersaturated medium usually cellulose and cooled by evaporation. When warm, dry unsaturated air is pulled through a watersoaked pad, water is evaporated and is absorbed as water vapor into the air. Design of new evaporative cooler and usage of different. Spx cooling technologies announces new recold lc evaporative condenser spx cooling technologies, inc. Jun 09, 2016 there are two types of evaporative cooling. His theory of adiabatic saturation and the standard psychrometric chart are its roots. Legionella risk in evaporative cooling systems and underlying.
Study, design and analysis of two stages evaporative cooling system prof. What are the advantages and disadvantages of evaporative cooling. The driving force of either direct or indirect evaporative cooling is the temperature difference between the drybulb table 1 a general comparison between the currently available air conditioning systems. The design will depend on the materials available and. The enthalpy of moist and humid air includes the enthalpy of the dry air the sensible heat and the enthalpy of the evaporated. Fan and pad greenhouse evaporative cooling systems 2 frequently drift out of calibration and should be checked against standards on a regular basis.
Thermogalvanic hydrogel for synchronous evaporative. Evaporative cooling is the natural way of cooling, similar to a breeze flowing across a lake. In this paper different cooling pads have been studied. Evaporative cooling design guidelines manual for new mexico schools and commercial buildings.
The basic design consists of a storage pot placed inside a bigger pot that holds water. Abstract this paper will present results from a recent study of energy efficiency opportunities in. Therefore, the performance demanded from the cooling tower is the inverse of this difference. Ware houses or garages, and it may also be used outofdoors on portico or on work sites.
Some examples of evaporative cooling designs are described below. With this technique, an airduct that is connected to an indirect air evaporative cooler is utilized. Performance analysis of an indirect evaporative cooling. Jul 02, 2014 drawbacks of evaporating cooling system. 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. The main disadvantage of this kind of particular cooling is that it is only applicable in dry atmospheres. Evaporative cooling design guidelines manual iii evaporative cooling design guidelines manual for new mexico schools and commercial buildings principal investigator. Performance evaluation of three different types of local. The evaporative cooler was tested and evaluated using tomato roma. There are two basic types of evaporative air coolers eacs. The heat from the primary air is transferred to a small amount of ambient scavenger air 3. Evaporative cooling systems use the same principle as perspiration to provide cooling for machinery and buildings. Energyefficient furnaceair conditioning airhandling cabinets. When the hydrogel is attached to a heat source, it can achieve efficient evaporative cooling while simultaneously converting a portion of the waste heat into electricity.
One must know them to understand the operation of evaporative coolers. Energy savings from indirect evaporative pre cooling. Developments in the evaporative cooling industry have reliably increased the efficiency. Performance analysis of an indirect evaporative cooling system using m cycle devang s. 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.
This technology is a combination of a desiccant dehumidifier and an evaporative cooler. Commercial industrial institutional evaporative cooling towers. Extreme heat and humidity can, and frequently does, cause heat strokes. Compared to airconditioning which uses mechanical refrigeration, the operating cost of heat evaporative. Evaporative cooling uses the fact that water will absorb a relatively large amount of heat in order to evaporate. Pdf a solar powered evaporative cooling system of 0. Primary air stream is sensibly cooled first with indirect evaporative cooling using a one side wet, cross counter flow heat exchanger. International journal of engineering research and general. Installing an evaporative cooling system is an alternative method of using an air conditioning system that pumps refrigerant through compression and evaporative cycles. Its material is chemically impregnated with special compounds to prevent rot and ensure a long service life.
The hot atoms leaving the trap are on the tail of the maxwellboltzmann distribution and. Cooling system optimization 5 18 12 chicago mccormick place jan 2224, 2018 register for free. Portable coolers cool small places or rooms, generally up to 300 square feet. At the point when considering evaporative cooling, one ought to figure out the wet knob and dry globule temperatures of the region. In this visual design blog, i detail the creative process of the cooler. Evaporative cooling, effectiveness, performance, energy saving. 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. Part of this research program investigated combinations of dehumidification and evaporative cooling in solardriven hybrid desiccant cooling systems. An evaporative cooler cools the air by means of the evaporation of water. Analysis of evaporative cooling system and recovery of. 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. Performance evaluation of alternative evaporative cooling media. The theory and operation of evaporative coolers for. Customers can replace an existing evaporative cooler or central ac system, or purchase a firsttime installed evaporative cooling unit, to qualify for a rebate.
Principles and application of evaporative cooling systems for. Evaporative cooling practical action 3 any part of the country using locally available materials. The systems design was based upon the humidifying capacity of an ultrasonic humidifier supplied by a quebec company, plastique frapa inc. Multitudes of combinations between refrigeration systems types, hvac system types and configurations, store sizes and new construction. Pot designs these are simple designs of evaporative coolers that can be used in the home.
There are mainly two basic types of evaporative cooling systems are present namely. Evaporative cooling is an atomic physics technique to achieve high phase space densities which optical cooling techniques typically can not reach atoms trapped in optical or magnetic traps are cooled as the trap depth is decreased and the hottest atoms with the highest kinetic energy leave the trap. The issues related to conventional air conditioning technology can be addressed using a new technology called desiccantbased evaporative cooling. Evaporative cooling principle for evaporative coolers evaporative air cooling systems. The schematic representation of desiccant cooling system is shown in figure 6.
Evaporative cooling an overview sciencedirect topics. Types of evaporative coolers direct evaporative coolers use a fan to pull outside air through media pads that are kept. Desiccant cooling systems are very good at providing latent cooling by reducing the humidity ratio of building air. S375s385 moist air is a mixture of dry air and water vapor.
Course contents evaporative coolers, often called swamp coolers, are cooling systems that use only water and a blower to circulate air. Reported cases of legionellosis attributed to types of water system. It is not only uncomfortable to work in, but it can be downright dangerous for the welfare of your workers. Evaporative cooling systems explained harry taylor. Evaporative cooling is the safest measure and includes cooling the patient with large fans after covering the patients body with a wet sheet. Study, design and analysis of two stages evaporative. Performance analysis of an indirect evaporative cooling system using m. Ca utilities 2011 title 24 stakeholder meeting for proposed code changes nov. Hybrid cooling that couples conventional highefficiency mechanical cooling with one or more evaporative cooling techniques to minimize compressor electricity. Hybrid direct expansion with evaporative precooling. Analysis of evaporative cooling system and recovery of potable water as by product amit dubey and anil kr tiwari department of mechanical engineering, national institute of technology raipur abstract. The equipment operates on the principle of evaporative cooling and increasing the relative hu midity rh in the preservation chamber. Schiano 2004 mentioned that porous pottery and clay jars were used for cooling in a system called muscatese evaporative cooling system.
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. In order to determine qualifying evaporative cooling equipment, public service works. Evaporative cooling guidelines manual quick reference field guide lesson. There are many different styles of evaporative coolers. New mexicans are most familiar with direct eacs that are also commonly used for residential cooling. Duan, zhiyin 2011 investigation of a novel dew point. Request pdf development and testing of twostage evaporative cooler. 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. Pdf design and construction of an evaporative cooling. The evaporative cooling systems has prospect for use for short term preservation of fruits and vegetables after harvested. An evaporative cooler is a device that cools air through the evaporation of water. Evaporative cooling is a physical phenomenon in which evaporation of a liquid, typically into surrounding air, cools an object or a liquid in contact with it.
Wet cooling towers or open circuit cooling towers fluid coolers or closed circuit cooling towers. Analysis of the evaporative towers cooling system of a coal s434 thermal science, year 2012, vol. Evaporative coolers are typically controlled using manual switches. During the last century evaporative cooling was reused for cooling in hot arid climates. It makes use of the free latent energy in the atmosphere. To evaporate 1kg of water into an atmosphere, 680w of energy is required. Evaporative cooler types evaporative coolers cool boss. Evaporative cooling differs from typical air conditioning systems, which use vaporcompression or absorption refrigeration cycles. Cooling tower water savings stakeholder meeting 2 erika walther energy solutions. For steam humidifiers, this energy typically comes from the electricity or gas being used to boil the water. The temperature of the water used with the evaporative cooler is also limited by the type of media. Case final evaporative cooler california energy commission. Evaporative cooling encourages customers and trade partners to purchase evaporative coolers also known as swamp coolers rather than central air conditioning.
Direct and indirect evaporative cooling strategies. Energy efficiency in industrial process cooling systems. Customers benefit by reducing the upfront cost of buying evaporative cooling units, saving energy throughout the lifetime of the equipment, and reducing electric bills. S431s442 point is the vertical distance between the two operating lines. What are the advantages and disadvantages of evaporative. The cooled air is circulated by a blower direct evaporative cooling adds moisture to the air stream until the air stream is close to saturation. Interviews with current users of evaporative cooling devices. The air temperature is lowered due to its contact with the water and has a relaxing, cooling effect on people.
Renewable and sustainable air conditioning intechopen. Evaporative cooling systems ecs, including cooling towers, used in industrial. All evaporative cooler types have one thing in common. A cooling tower is a heatrejection device, which discharges warm air from the cooling tower to the atmosphere through the cooling of water. Energy savings from indirect evaporative precooling.
Evaporative cooling is the most applied cooling technology in the world. Development and testing of twostage evaporative cooler request. This adiabatic cooling process is also used to create the chilled water that feeds our indirect evaporative cooling coil. Primary air is cooled further with direct evaporative cooling. Analysis of advanced solar hybrid desiccant cooling. Three different types of evaporative cooling pads were used, namely. Evaporative cooling occurs when air, that is not too humid, passes over a wet. In summary, evaporative cooling is the process of removing heat from a surface due to the evaporation of water. It is not successful in the areas where the dampness is high. It also provides a range for the roughness of each type of duct in each category.
Evaporative cooling may be achieved by mechanical or passive wind induced means. Adiabatic cooling adiabatic cooling occurs when the temperature of water. A combination indirect and direct evaporative cooling can create cooler temperatures than. Many households use conventional cooling systems as a backup to their evaporative cooling systems during these periods. Biggest problem facing the indirect evaporative cooling iec technology lies in its high level of dependency to ambient air condition. Moreover, the hydrogel can absorb water from the surrounding air to regenerate its water content later on. The concept of watercooling a roof has a long history but it is estimated that less than 60 million square feet of roof have. Performance evaluation of alternative evaporative cooling. However, when the desiccant cooling system must handle the entire load, it overdries the process air so evaporative cooling can be used for the sensible cooling. The best time to measure wet bulb temperature to calculate the potential cooling performance of the evaporative cooling system is in. In a desiccant cooling system, air can be passed over common solid desiccants such as zeolite or silica gel for dehumidification and to sensibly cool the air well below ambient temperature conditions in some form of evaporative cooling process.
721 453 1009 250 1536 193 831 1307 502 207 99 696 570 1146 1380 475 1377 390 869 1233 685 346 207 640 528 1090 967 1441 83 352 509 1466