Waterbased evaporative cooling technologies have been used for many centuries to provide comfort in cities. Performance evaluation for indirect evaporative cooling etsce7 southern california edison page iii emerging products june 2015 abbreviations and acronyms 6 cooling capacity, enthalpy flow rate e. The theory of direct evaporative cooling owes much to dr. 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. There are three main types of ieacs, and all of them use the same evaporative cooling process as direct evaporative cooling, known as adiabatic cooling.
Highpressure system first costs are generally higher than other adiabatic systems due, mostly, to the cost of adding. Your evaporative air conditioner has control switches to provide for the benefits of fresh air ventilation and cooling at high and low air flows. Many households use conventional cooling systems as a backup to their evaporative cooling systems during these periods. It will consist of the component parts as listed in the following sections. Principles and application of evaporative cooling systems for. During the process of perspiration, it absorbs heat to cool the body. Evaporative cooling concept, maximum cooling temperature. Evaporative cooling an overview sciencedirect topics. A cooling tower is a heatrejection device, which discharges warm air from the cooling tower to the atmosphere through the cooling of water. We are dedicated to designing and manufacturing the highest quality products for the evaporative cooling and industrial refrigeration markets around the globe. Principles and application of evaporative cooling systems.
In summary, evaporative cooling is the process of removing heat from a surface due to the evaporation of water. Some examples of evaporative cooling designs are described below. Cooling through evaporation is the natural occurrence. Technical information for cooling towers using recycled water. Types of evaporative coolers direct evaporative coolers use a fan to pull outside air through media pads that are kept. It takes heat energy to change the water or any liquid from a liquid into a vapor. As the name implies, evaporative cooling works by evaporating water into the air stream. The operating principles of these devices are based on four essential methods of action. A potinpot refrigerator, clay pot cooler or zeer arabic. Evaporative cooler engineering specification 598 1.
In the hvac industry, the term cooling tower is used to describe both open and. The movement of this fresh cooled air over the skin is what makes it feel cool. Practical action in sudan and humanity first in gambia and. Evaporative cooling occurs when air, that is not too humid, passes over a wet. 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 direct cooling under the influence of sinking cold air is accompanied by evaporative cooling, induced by evaporation of moisture from the walls wigley and brown, 1976. It could be a factoryassembled packaged unit or a fieldbuilt system. The water exits the cooling tower and is sent back to the exchangers or to other units for further cooling. Evaporative cooling differs from typical air conditioning systems, which use vaporcompression or absorption refrigeration cycles. 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. Installing an evaporative cooling system is an alternative method of using an air conditioning system that pumps refrigerant through compression and evaporative cycles. This is the most common form of evaporative cooling strategy used in air handling units.
Evaporative cooling systems maintain better air quality and eliminate more allergens than an equivalent ac system. In order for evaporative coolers to be effective in an enclosed area, a fresh air source. Help demonstrate corporate environmental credentials. In order for evaporative coolers to be effective in an enclosed area, a fresh air. Evaporativecooling air conditioning systems use the cooling effect of the evaporation of liquid water to cool an air stream directly or indirectly. When warm, dry unsaturated air is pulled through a watersoaked pad, water is evaporated and is absorbed as water vapor into the air. Cooling tower types cooling towers fall into two main categories.
Because of this limitation, this type of equipment is also named wet bulb iec. Evaporative cooling food and agriculture organization of the. The indirect evaporative section also incorporates a scavenger fan to exhaust air through the pipes, a water distribution system which includes a water pump and spray nozzles to provide a uniform distribution over the entire heat exchanger, and a filter section to clean and maintain incoming air into the system. Performance evaluation of alternative evaporative cooling media. However, buildings electricity bills have become unaffordable. They are also referred to as swamp coolers and are extremely efficient, especially in lowhumidity areas. The systems design was based upon the humidifying capacity of an ultrasonic humidifier supplied by a quebec company, plastique frapa inc. Heatingcooling evaporative swamp coolers evaporative. 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 performance is directly related to its ability to evaporate water cool at a given relative humidity. By incorporating in our direct evaporative cooler with our indirect evaporative cooler you get the best of both worlds. This is placing great pressures on an electric grid that must. Voiceover so if you are like most of us, your body probably sweats when it is warm, when your environment is warm, and you probably realize that it sweats in order to cool itself, in order to keep the body from overheating. 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.
For steam humidifiers, this energy typically comes from the electricity or gas being used to boil the water. The evaporative cooler was tested and evaluated using tomato roma. Direct and indirect evaporative cooling strategies. In summer, the air inside the cave is colder and thus heavier than the external one and is trapped inside the cave, hence the name of the phenomenon. Your control panel offers independent control for the fan and cooling functions. Furnish proof satisfactory to the owner or his representative, of. Air is cooled while being drawn across wet evaporative media. Matthaios santamouris, in minimizing energy consumption, energy poverty and global and local climate change in the built environment. The conversion of sensible heat to latent heat causes a decrease in the ambient temperature as water is. Evaporative cooling systems, which dont need potable water, are a good use of recycled. Evaporative cooling practical action 3 any part of the country using locally available materials. 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. 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. Although there are several types of evaporative coolers, including indirect.
Given the wide availability of both clay pots and plastic dishes, local business could assemble. To evaporate 1kg of water into an atmosphere, 680w of energy is required. All evaporative cooler types have one thing in common. Types of evaporative cooling evaporative cooling works by employing waters large. In sudan, practical action and the womans association for earthenware manufacturing have been. Typical closed loop cooling tower system is shown in figure 7. Munters systems use cooling heat rejection strategies that achieve a balance of reliability and energy efficiency for data centers, some using as little as 20% of the cooling energy required by conventional cooling systems. You get 2 stages of evaporative cooling while offsetting substantial energy costs. His theory of adiabatic saturation and the standard psychrometric chart are its roots. Evaporative cooling uses the fact that water will absorb a relatively large amount of heat in order to evaporate. Evaporative cooling, on the other hand, relies instead on the inherent quality of water to absorb heat when it evaporates changes from a liquid to a gas. The conversion of sensible heat to latent heat causes a decrease in the ambient temperature as water is evaporated providing useful cooling.
Yet the commercially dominant cooling systems are intensively powerconsuming ones, i. This manual is intended to be used as a tool for the design of successful and efficient evaporative cooling systems and will allow engineers to specify and design evaporative cooling systems with confidence. The equipment operates on the principle of evaporative cooling and increasing the relative hu midity rh in the preservation chamber. Fan and pad greenhouse evaporative cooling systems 3 area covered by plants, and floor material i. The dryer the air, the greater shall be the performance.
About evaporative cooling evaporative cooling is an economical way to cool and is highly effective in arid climates. Not a new technology first recorded use was in the thirties and used cooling tower and coils first use with the integral heat exchangercooling tower was in 1975 and it was then that the term indirect evaporative cooling was coined from 1975 to 1985 iec was. Cooling is provided whilst keeping the evaporative process outside, which avoids elevating the indoor humidity level. Munters systems use coolingheat rejection strategies that achieve a balance of reliability and energy efficiency for data centers, some using as little as 20% of the cooling energy required by conventional cooling systems. Improved iaq, resulting from higher ventilation rates when cooling is required 3. Evaporative cooling is a reliable, lowtech method to provide cooler air during hot weather. This principle is best illustrated in a personal way by chilling effect that you feel when you come out of a swimming pool and a wind blows across your body. Evaporative air coolers should be maintained in accordance with asnzs 3666. With oasis, the energy required to remove heat is significantly reduced. What are the advantages and disadvantages of evaporative. Try a new, improved swamp cooler green homes mother. Experience has shown that air may heat up as rapidly as 1f every 10 feet as it moves across the greenhouse on sunny summer days. In this paper different cooling pads have been studied. 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.
These hvacs come factory assembled, prewired, and are self contained, packaged units. How free is evaporative cooling in the data center green. Coolspace evaporative cooling coolspace avalanche36vd cs636vd portable evaporative cooler. Evaporative cooling systems use the same principle as perspiration to provide cooling for machinery and buildings. Indirect evaporative cooler westaire engineering inc. 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. The cooling energy requirements are certainly a key issue in warm climates. One must know them to understand the operation of evaporative coolers. The humidifier adds water to the incoming air stream, raising its humidity and reducing its temperature.
They supply a steady stream of fresh air into a home, rather than recirculating the same air. Coolspace evaporative cooling coolspace avalanche361d cs6361d portable evaporative cooler. Evaporative cooling is based on the thermodynamics of evaporation of water, i. I wont go into the details of what types of molecules these are, but then if you have your water molecules here, water molecules that are sitting on the surface, and im. 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.
In order to limit the noise level, actions can be taken. We build any size of idct with any type of structure. The roof configuration can also influence the temperature increase. Locally, biogen idec, a company specializing in the development of. The evaporative cooling module shall be selfcontained. Biggest problem facing the indirect evaporative cooling iec technology lies in its high level of dependency to ambient air condition. Evaporative cooler types evaporative coolers cool boss. International journal of engineering research and general. Water can absorb a lot of heat without changing phases, allowing it to remove heat. Direct evaporative cooling provides air washing that removes some pollen and other particulate benefits of applying direct evaporative cooling. F as in the above example, the cooling efficiency is 90%. It is not only uncomfortable to work in, but it can be downright dangerous for the welfare of your workers. Generally evaporative air cooling is effective for comfort cooling at wet.
Evaporative cooling is the process of cooling an area through the evaporation of water. 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. This system is the oldest and the simplest type of evaporative cooling in which the outdoor air is brought into direct contact with water, i. The primary responsibility of a business man is to provide the secure and comfortable feeling to the clients who visit their office. Evaluation of evaporative cooling systems in industrial buildings. Evaporative cooling, effectiveness, performance, energy saving. The successful application of evaporative air cooling will depend on the geographic location of the site, the local climate, and the owners performance expectations for the cooling system i. A direct evaporative cooling system is the simplest and most popular evaporative cooling system available. Extreme heat and humidity can, and frequently does, cause heat strokes. The most common example in human is the process of perspiration. When evaporative processes are used to cool an element of the building, which then acts as a heat sink, this is known as indirect evaporative cooling. Nonresidential evaporative air cooling systems airah.