These systems use only a fraction of the energy of typical compressorbased cooling systems. 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. Evaporative coolers, also called swamp coolers, rely on this principle, cooling outdoor air by passing it over watersaturated pads, causing the water to evaporate into it. Extreme heat and humidity can, and frequently does, cause heat strokes. In summary, evaporative cooling is the process of removing heat from a surface due to the evaporation of water. Direct evaporative cooling system and indirect evaporative cooling system. The cost of an evaporative cooling system may be higher than a vaporcompression chiller system, but payback is typically six month to five years depending on climate. 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. The evaporative cooler was tested and evaluated using tomato roma. Moisture can be added to the air stream until saturation. Background evaporative condensers came into common use for nearly all refrigeration systems because of their operating advantages over the combination of cooling towers and condensers. Introduction to commercial building hvac systems and energy.
How free is evaporative cooling in the data center green. Pdf cooling systems in buildings are required to be more energyefficient while. Evaporative cooling is a reliable, lowtech method to provide cooler air during hot weather. Pdf evaluation of evaporative cooling systems in industrial buildings. As it passes through these pads the air is cooled and filtered before flowing through the ductwork and into your rooms just like a cool, refreshing sea breeze. In this system, the natural convection of water is used.
International journal of engineering research and general. Used in conjunction with coolair fans, a temperature reduction of 1025 degrees is commonplace. Evaporative cooling is based on the thermodynamics of evaporation of water, i. Evaporative cooling food and agriculture organization of. 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.
Evaporative cooling systems can significantly lower the outside air temperature, even in humid climates, and improves the ability of the ventilation air to reduce the heat in the area. Benefits of evaporative coolingcondensing precautions of evaporative coolingcondensing explain latest technologies ducting, controls, humidity control, water treatment, life cycle cost benefits properly size to meet weather conditions and customer needs properly install to prevent installation related problems. E odoc adepartment of agricultural and bioresources engineering, university of nigeria, nsukka bdepartment of nursing science, university of maiduguri, borno state, nigeria. Anyone who has spent some time in a hot, stuffy warehouse understands how torturous heat and humidity can be. The only significant energy use is in the fan for the air movement. In central hvac systems, cooling systems based on indirect evaporative cooling are becoming increasingly important.
It is used in data center and large it facilities to provide air cooling conditioning services. An evaporative cooling system for turbine inlet air is a useful option for installations where high ambient temperatures and low relative humidity are common. Evaporative cooling will always follow the laws of nature, so when hot and dry conditions exist, the properly designed and maintained evaporative system will always perform cooling, as sure as a thrown rock will fall to the ground. Evaporative cooling is a type of environment cooling techniques that cools the surrounding air using water evaporation technique. Evaporative cooler engineering specification 598 1. When you are in the process of choosing a cooling system for your new home, you will come across an array of different options. Peak summer hour electricity and water costs were calculated to compare equivalent cooling costs applicable to a 2600 square foot area portable classroom. Evaporative cooling uses the fact that water will absorb a.
New mexicans are most familiar with direct eacs that are also commonly used for residential cooling. The design will depend on the materials available and the users requirements. When warm, dry unsaturated air is pulled through a watersoaked pad, water is evaporated and is absorbed as water vapor into the air. An evaporative cooling system is an air conditioning system in which air is evaporated cooled just like how, the body. For steam humidifiers, this energy typically comes from the electricity or gas being used to boil the water. Evaporative cooling systems maintain better air quality and eliminate more allergens than an equivalent ac system. Portable coolers cool small places or rooms, generally up to 300 square feet. The concept of evaporative cooling came from the sweating of our bodies. Water can absorb a lot of heat without changing phases, allowing it to remove heat.
Using a control system to minimise energy usage of fans coupled with evaporative cooling, relatively low flow rates of air are required. Commercial and industrial evaporative cooling systems. Typically a 1kw evaporative cooling system can manage a 20kw load. Evaporative cooling guidelines manual quick reference field guide lesson. 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. Furnish proof satisfactory to the owner or his representative, of. Pdf new integrated hybrid evaporative cooling system for hvac. Moreover, a kind of indirect evaporative cooling systems, called cyclic evaporative cooling, in which. Course contents evaporative coolers, often called swamp coolers, are cooling systems that use only water and a blower to circulate air. Evaporative cooler types evaporative coolers cool boss.
Principles and application of evaporative cooling systems. Study, design and analysis of two stages evaporative. This is placing great pressures on an electric grid that must. Installing an evaporative cooling system is an alternative method of using an air conditioning system that pumps refrigerant through compression and evaporative cycles. Evaporative cooling, effectiveness, performance, energy saving. Evaporative cooling differs from typical air conditioning systems, which use vaporcompression or absorption refrigeration cycles.
Direct and indirect evaporative cooling strategies. Evaporative cooling systems use the same principle as perspiration to provide cooling for. Brivis evaporative cooling comprises a central cooling unit connected to a series of outlets throughout your home. An evaporative cooling system is an air conditioning system in which air is evaporated cooled just like how, the body perspires on a hot day and this moisture evaporates into the.
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. The evaporative cooling system will cool compressor intake air through humidification. The 15 to 40fcooler air is then directed into the home, and pushes warmer air out through windows. Study, design and analysis of two stages evaporative cooling. Airconditioning hvac systems as they relate to energy code requirements. What is twostage evaporative cooling system and how it. Technology, markets, and economics larry kinney, southwest energy efficiency project abstract the southwest is growing rapidlya 37% increase in population is projected from 2000 to 2020 versus 16% for the total us. Ware houses or garages, and it may also be used outofdoors on portico or on work sites. This is the result of the relationship between the cold work generated by the evaporative cooling and the pump work required for the evaporation water and the ventilator work to overcome the airside loss of pressure of the evaporative cooling system. Developments in the evaporative cooling industry have reliably increased the efficiency. When sweat evaporates from the skin, a large amount of heat is required. Evaluation of evaporative cooling systems in industrial buildings. Evaluation of evaporative cooling systems in industrial buildings article pdf available in international journal of heat and technology 333.
The intake air will have a higher relative humidity and lower temperature. Evaporative cooling systems to improve internal comfort in industrial. Pdf a solar powered evaporative cooling system of 0. The economics of using evaporative cooling are surprising to people. At the point when considering evaporative cooling, one ought to figure out the wet knob and dry globule temperatures of the region. It will consist of the component parts as listed in the following sections. Evaporative cooling is also known as swamp cooling, desert cooling and wet air cooling. 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. An emerging solution for homes in hot dry climates with modest cooling loads. Pdf evaluation of evaporative cooling systems in industrial. A heat section can be added to most models to provide a ventilation unit for year round use. The rate of evaporative cooling is a function of both humidity and air movement. These consist of an alton direct evaporative cooling unit dec or an aztec series that can be set up as either an indirect or indirect direct unit idec.
The cooling unit draws fresh air through moistened pads. Applied air offers direct evaporative cooling equipment with air deliveries from 3,000 cfm to 64,000 cfm and indirect or indirectdirect evaporative cooling. The systems design was based upon the humidifying capacity of an ultrasonic humidifier supplied by a quebec company, plastique frapa inc. What are the advantages and disadvantages of evaporative. This design guidelines manual for evaporative cooling addresses the relative. Unique design with high efficiency evaporative cooling pads. The equipment operates on the principle of evaporative cooling and increasing the relative hu midity rh in the preservation chamber. In a direct evaporative cooling system outside air is pulled through a watersaturated medium typical cellulose or air is sprayed with water and cooled by evaporation. This report was prepared as an account of work sponsored by an agency of the state of new mexico. Study, design and analysis of two stages evaporative cooling system prof.
A seasonal performance factor is also shown in the results. When evaporation occurs, this heat is taken from the water that remains in the liquid state, resulting in a cooler liquid. Why do we need to run an air con system when there is an ambient temperature of 10c. From the traditional central cooling system to the window air units some homeowners use, each method has its own drawbacks and advantages. Evaporative cooling is a physical phenomenon in which.
To help you understand which type of unit we are talking about throughout this technical guide. The main disadvantage of this kind of particular cooling is that it is only applicable in dry atmospheres. Evaporative cooling ec, also known as swamp cooling, is a strategy for cooling air that takes advantage of the drop in temperature that occurs when water thats exposed to moving air begins to vaporize and change to gas. The principle underlying evaporative cooling is the fact that water must have heat applied to it to change from a liquid to a vapor. Pot designs these are simple designs of evaporative coolers that can be used in the home. What is data center evaporative cooling swamp cooling. We offer two different system types of evaporative cooling units. Evaporative cooling pads that are saturated with water, a substantial cooling effect is realized due to the evaporation of that water. Direct indirect with direct evaporative cooling, outside air is blown through a watersaturated medium usually cellulose and cooled by evaporation. The process is indicated in the psychrometric chart below. View evaporative cooling research papers on academia. Assessment of marketready evaporative technologies for hvac.
There are two basic types of evaporative air coolers eacs. The control of legionella bacteria in evaporative cooling systems. The hot water in the water jacket rises up by this way and goes radiator top, from where it passes down and is cooled, and is collected in the bottom tank. This is achieved because in the uk it is cold most of the time. When warm, dry unsaturated air is pulled through a water soaked pad, water is evaporated and is absorbed as water vapor into the air. If youre behind a web filter, please make sure that the domains. A twostage evaporative cooling system can deliver cool indoor air with a relative humidity in the 50%65% range, while direct evaporative cooling systems typically condition the air at around 70% relative humidity. Pdf the cooling energy requirements are certainly a key issue in warm climates. The evaporative cooling module shall be selfcontained. Pdf design and construction of an evaporative cooling. If youre seeing this message, it means were having trouble loading external resources on our website. Installation and maintenance of evaporative cooling system. Leadership in energy and environmental design leed points can be achieved by using cooling options that operate more ef.
Design of new evaporative cooler and usage of different. It is the heat energy, which changes the water to vapor. There are two basic types of evaporative air coolers eacs used to cool new mexico schools and. Some examples of evaporative cooling designs are described below. Evaporative coolers, often called swamp coolers, are cooling systems that use only water and a blower to circulate air. Principles and application of evaporative cooling systems for fruits and vegetables preservation j.
Choosing an evaporative cooling system offers a substantial energy cost savings. Industrial buildings have some features that make them very different than all other types of buildings like dwelling, offices, schools, hospitals. It is not only uncomfortable to work in, but it can be downright dangerous for the welfare of your workers. Suited for virtually all geographic locations, the. To evaporate 1kg of water into an atmosphere, 680w of energy is required.
All evaporative cooler types have one thing in common. Evaporative cooling evaporative cooling is a very efficient means of heat dissipation, as one litre evaporated sweat removes 672 wh from the body at a temperature of 35 c. They, of course, have also replaced the old once through water cooled condensing systems which are obsolete today. Also, liquid dessicants such as lithium or calcium chloride have. Onoff, scheduling, lo fan, hi fan, pump wet medium. Residential and small commercial systems of this type also have the. 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. Indirect evaporative cooling can be used to lower both the dry bulb and wet bulb temperatures. In the extreme case of air that is totally saturated with water, no evaporation can take place and no cooling occurs. The basic design consists of a storage pot placed inside a bigger pot that holds water. Types of evaporative coolers direct evaporative coolers use a fan to pull outside air through media pads that are kept. What are the advantages and disadvantages of evaporative cooling. Many households use conventional cooling systems as a backup to their evaporative cooling systems during these periods. 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.
The evaporative cooler was tested and evaluated using. Applied air offers direct evaporative cooling equipment with air deliveries from 3,000 cfm to 64,000 cfm and indirect or indirectdirect evaporative cooling units with air deliveries from 1,500 cfm to 37,500 cfm. Evaporative cooling an overview sciencedirect topics. Highlyefficient evaporative cooling systems can reduce energy use by 70% the actual savings will vary with the type of evaporative system and climate. An 85% reduction in energy used compared to a air con unit seems too good to be true.
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. In lowhumidity areas, evaporating water into the air provides a natural and energyefficient means of cooling. For this, we propose a new hybrid evaporative cooling system for hvac efficiency improvement. It is not successful in the areas where the dampness is high.
640 1147 501 710 579 476 146 573 1039 479 1198 194 6 991 405 764 461 596 1200 1431 972 54 155 29 1317 896 726 181 1226 354 1414 477 962 1178 1219 293 319 1241 1406