evaporative cooler - wikipedia, the free encyclopedia

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/ 28/ 12 Ev aporat iv e cooler - W ikipedia, the f ree ency c lopedia

.wikipedia.org/wiki/Ev aporativ e_cooler

An evaporative cooler, photographedin Rocky Ford, Colorado, used in thedrier parts of the American West to

provide economical cooling

Evaporative coolerFrom Wikipedia, the free encyclopedia

An evaporative cooler (also swamp cooler, desert cooler, and wetair cooler) is a device that cools air through the evaporation of water.Evaporative cooling differs from typical air conditioning systems whichuse vapor-compression or absorption refrigeration cycles. Evaporative

cooling works by employing water's large enthalpy of vaporization. Thetemperature of dry air can be dropped significantly through the phasetransition of liquid water to water vapor (evaporation), which can cool airusing much less energy than refrigeration. In extremely dry climates,evaporative cooling of air has the added benefit of conditioning the airwith more moisture for the comfort of building occupants. Unlike closed-cycle refrigeration, evaporative cooling requires a water source, and mustcontinually consume water to operate.

Air washers and wet cooling towers use the same principles as

evaporative coolers but are designed for purposes other than directlycooling the air inside a building. For example, an evaporative cooler may be designed to cool the coils of a large aiconditioning or refrigeration system to increase its efficiency.

Contents

1 History2 Physical principles

2.1 Other types of phase-change cooling3 Applications

3.1 Other examples4 Evaporative cooler designs

4.1 Typical installations4.2 Evaporative (wet) cooling towers4.3 Misting systems

4.3.1 Misting fans5 Performance6 Comparison to air conditioning

6.1 Advantages6.2 Disadvantages

7 See also8 References9 External links

History
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Ev aporativ e cooler - Wikipedia, the f ree ency clopedia

2.wikipedia.org/wiki/Ev aporativ e_cooler

Schematic diagram of an ancientIranian windcatcher and qanat, usedfor evaporative cooling of buildings(click image to enlarge)

Civilizations throughout the ages have found ingenious ways to combatthe heat in their region. An earlier form of air cooling, the windcatcher(Bd gir), was invented in Persia (Iran) thousands of years ago in theform of wind shafts on the roof, which caught the wind, passed it oversubterranean water in a qanatand discharged the cooled air into the

building. Nowadays Iranians have changed the windcatcher into anevaporative cooler (Coolere bi) and use it widely.[1] There are 9 millionevaporative coolers in central Iran, and in just the first two months ofear 1385 in the Persian/Iranian calendar (AprilMay 2006) 130,000

evaporative coolers were sold in Iran.[2]

The evaporative cooler was the subject of numerous US patents in the20th century; many of these, starting in 1906,[3] suggested or assumedthe use of excelsior (wood wool) pads as the elements to bring a largevolume of water in contact with moving air to allow evaporation to occur.A typical design, as shown in a 1945 patent, includes a water reservoir (usually with level controlled by a floatvalve), a pump to circulate water over the excelsior pads and a squirrel-cage fan to draw air through the pads and

into the house.

[4]

This design and this material remain dominant in evaporative coolers in the American Southwest,where they are also used to increase humidity.[5] In the United States, the use of the termswamp coolermay bedue to the odor of algae produced by early units.[6]

Evaporative cooling was in vogue for aircraft engines in the 1930s, for example with the Beardmore Tornadoairship engine. Here the system was used to reduce, or eliminate completely, the radiator which would otherwisecreate considerable drag. In these systems the water in the engine was kept under pressure with pumps, allowing ito heat to temperatures above 100C, as the actual boiling point is a function of the pressure. The superheatedwater was then sprayed through a nozzle into an open tube, where it flashed into steam, releasing its heat. The tubecould be placed under the skin of the aircraft, resulting in a zero-drag cooling system.[citation needed]

However these systems also had serious disadvantages. Since the amount of tubing needed to cool the water waslarge, the cooling system covered a significant portion of the plane even though it was hidden. This addedcomplexity and reliability issues. In addition this large size meant it was very easy for it to be hit by enemy fire, and

practically impossible to armor. British and U.S. developers used ethylene glycol instead, cooling the liquid inradiators. The Germans instead used streamlining and positioning of traditional radiators. Even the method's mostardent supporters, Heinkel's Gnter brothers, eventually gave up on it in 1940.[citation needed]

Externally-mounted evaporative[7] cooling devices to cool interior air were used in some automobiles, often asaftermarket accessories, until modern vapor-compression air conditioning became widely available.

Physical principles

Evaporative cooling is a physical phenomenon in which evaporation of a liquid, typically into surrounding air, coolsan object or a liquid in contact with it. Latent heat, the amount of heat that is needed to evaporate the liquid, isdrawn from the air. When considering water evaporating into air, the wet-bulb temperature which takes bothtemperature and humidity into account, as compared to the actual air temperature (dry-bulb temperature), is ameasure of the potential for evaporative cooling. The greater the difference between the two temperatures, thegreater the evaporative cooling effect. When the temperatures are the same, no net evaporation of water in airoccurs, thus there is no cooling effect. The wet-bulb temperature is essentially the lowest temperature which can b
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attained by evaporative cooling at a given temperature and humidity.

A simple example of natural evaporative cooling is perspiration, or sweat, secreted by the body, evaporation ofwhich cools the body. The amount of heat transfer depends on the evaporation rate, however for each kilogram ofwater vaporized 2,257 kJ of energy (about 890 BTU per pound of pure water, at 95F) are transferred. Theevaporation rate depends on the temperature and humidity of the air, which is why sweat accumulates more on hohumid days, as it does not evaporate fast enough.

Vapor-compression refrigeration uses evaporative cooling, but the evaporated vapor is within a sealed system, anis then compressed ready to evaporate again, using energy to do so. A simple evaporative cooler's water isevaporated into the environment, and not recovered. In an interior space cooling unit, the evaporated water isintroduced into the space along with the now-cooled air; in an evaporative tower the evaporated water is carriedoff in the airflow exhaust.

Other types of phase-change cooling

A closely related process, sublimation cooling differs from evaporative cooling in that a phase transition from solto vapor, rather than liquid to vapor occurs.

Sublimation cooling has been observed to operate on a planetary scale on the planetoid Pluto, where it has beencalled an anti-greenhouse effect.[citation needed]

Another application of a phase change to cooling is the "self-refrigerating" beverage can. A separate compartmentinside the can contains a desiccant and a liquid. Just before drinking, a tab is pulled so that the desiccant comes intcontact with the liquid and dissolves. As it does so it absorbs an amount of heat energy called the latent heat offusion. Evaporative cooling works with the phase change of liquid into vapor and the latent heat of vaporization, buthe self-cooling can uses a change from solid to liquid, and the latent heat of fusion to achieve the same result.

Applications

Before the advent of refrigeration, evaporative cooling was used for millennia. A porous earthenware vessel wouldcool water by evaporation through its walls; frescoes from about 2500 BC show slaves fanning jars of water tocool rooms.[8] A vessel could also be placed in a bowl of water, covered with a wet cloth dipping into the water, keep milk or butter as fresh as possible.[9]

Evaporative cooling is a common form of cooling buildings for thermal comfort since it is relatively cheap andrequires less energy than other forms of cooling. However, evaporative cooling requires an abundant water sourceas an evaporate, and is only efficient when the relative humidity is low, restricting its effective use to dry climates.Evaporative cooling also raises the internal humidity level significantly, which can cause problems such as lumpytable salt; swelling and warping of wood paneling, doors and trim; pianos going out of tune or suffering internalrusting, etc.

Evaporative cooling is especially well suited for climates where the air is hot and humidity is low. In the UnitedStates, the western/mountain states are good locations, with evaporative coolers prevalent in cities like Denver, SaLake City, Albuquerque, El Paso, Tucson, and Fresno where sufficient water is available. Evaporative airconditioning is also popular and well-suited to the southern (temperate) part of Australia. In dry, arid climates, theinstallation and operating cost of an evaporative cooler can be much lower than that of refrigerative air conditioningoften by 80% or so. However, evaporative cooling and vapor-compression air conditioning are sometimes used in
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California ranch house withevaporative cooler box on roofridgeline (click image to enlarge)

combination to yield optimal cooling results. Some evaporative coolersmay also serve as humidifiers in the heating season.

In locations with moderate humidity there are many cost-effective usesfor evaporative cooling, in addition to their widespread use in dryclimates. For example, industrial plants, commercial kitchens, laundries,dry cleaners, greenhouses, spot cooling (loading docks, warehouses,factories, construction sites, athletic events, workshops, garages, and

kennels) and confinement farming (poultry ranches, hog, and dairy) oftenemploy evaporative cooling. In highly humid climates, evaporative coolingmay have little thermal comfort benefit beyond the increased ventilationand air movement it provides.

Other examples

On Earth, trees transpire large amounts of water through pores in their leaves called stomata, and through thisprocess of evaporative cooling, forests interact with climate at local and global scales.[10]

Evaporative cooling is commonly used in cryogenic applications. The vapor above a reservoir of cryogenic liquid ipumped away, and the liquid continuously evaporates as long as the liquid's vapor pressure is significant.Evaporative cooling of ordinary helium forms a 1-K pot, which can cool to at least 1.2 K. Evaporative cooling ofhelium-3 can provide temperatures below 300 mK. These techniques can be used to make cryocoolers, or ascomponents of lower-temperature cryostats such as dilution refrigerators. As the temperature decreases, the vapo

pressure of the liquid also falls, and cooling becomes less effective. This sets a lower limit to the temperatureattainable with a given liquid.

Evaporative cooling is also the last cooling step in order to reach the ultra-low temperatures required for BoseEinstein condensation (BEC). Here, so-called forced evaporative cooling is used to selectively remove high-

energetic ("hot") atoms from an atom cloud until the remaining cloud is cooled below the BEC transitiontemperature. For a cloud of 1 million alkali atoms, this temperature is about 1K.

Although robotic spacecraft use thermal radiation almost exclusively, many manned spacecraft have short missionsthat permit open-cycle evaporative cooling. Examples include the Space Shuttle, the Apollo Command/ServiceModule (CSM), Lunar Module and Portable Life Support System. The Apollo CSM and the Space Shuttle alsohad radiators, and the Shuttle could evaporate ammonia as well as water. The Apollo spacecraft used sublimatorscompact and largely passive devices that dump waste heat in water vapor (steam) that is vented tospace.[citation needed] When liquid water is exposed to vacuum it boils vigorously, carrying away enough heat tofreeze the remainder to ice that covers the sublimator and automatically regulates the feedwater flow depending on

the heat load. The water expended is often available in surplus from the fuel cells used by many manned spacecraftto produce electricity.

Evaporative cooler designs

Most designs take advantage of the fact that water has one of the highest known enthalpy of vaporization (latentheat of vaporization) values of any common substance. Because of this evaporative coolers use only a fraction ofthe energy of vapor-compression or absorption air conditioning systems. Unfortunately, except in very dry climatethe single-stage (direct) cooler can increase relative humidity to a level that makes occupants uncomfortable.
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Evaporative cooler illustration

Indirect and Two-stage evaporative coolers keep the RH lower.

Direct evaporative cooling (open circuit) is used to lower the temperature of air by using latent heat ofevaporation, changing liquid water to water vapor. In this process, the energy in the air does not change. Warm drair is changed to cool moist air.The heat of the outside air is usedto evaporate water. The RelativeHumidity increases to 70 to 90%

which reduces the cooling effect ofhuman perspiration. The moist airhas to be continually released tooutside or else the air becomessaturated and evaporation stops.

Indirect evaporative cooling

(closed circuit) is similar to directevaporative cooling but uses sometype of heat exchanger. The

cooled moist air never comes indirect contact with the conditioned air. The moist air stream is released outside or used to cool other externaldevices such as solar cells which are more efficient if kept cool. One indirect cooler manufacturer uses the so-calleMaisotsenko cycle which employs an iterative (multi-step) heat exchanger that can reduce the temperature to belothe wet-bulb temperature.[11] While no moisture is added to the incoming air the RH does rise a little according tothe Temperature-RH formula. Conditioned air without added moisture increases the evaporation of perspirationimproving the cooling effect of Indirect compared to Direct.

Two-stage evaporative cooling, orindirect-direct. In the first stage of a two-stage cooler, warm air is pre-cooled indirectly without adding humidity (by passing inside a heat exchanger that is cooled by evaporation on the

outside). In the direct stage, the pre-cooled air passes through a water-soaked pad and picks up humidity as itcools. Since the air supply is pre-cooled in the first stage, less humidity is transferred in the direct stage, to reach thdesired cooling temperatures. The result, according to manufacturers, is cooler air with a relative humidity between50-70%, depending on the climate, compared to a traditional system that produces about 7080% relativehumidity in the conditioned air.[citation needed]

Hybrid. Direct or Indirect cooling has been combined with vapor-compression or absorption air conditioning toincrease the overall efficiency and /or to reduce the temperature below the wet-bulb limit.

Materials. Traditionally, evaporative cooler pads consist of excelsior (wood wool) (aspen wood fiber) inside a

containment net, but more modern materials, such as some plastics and melamine paper, are entering use as coolepad media. Wood absorbs some of the water and has a larger surface area which allows the wood fibers to coolpassing air to a lower temperature than some synthetic materials, but natural fibers also can pose a problem withharboring or supporting mildew growth.

Typical installations

Typically, residential and industrial evaporative coolers use direct evaporation, and can be described as an enclosemetal or plastic box with vented sides. Air is moved by a centrifugal fan or blower, (usually driven by an electricmotor with pulleys known as "sheaves" in HVAC terminology, or a direct-driven axial fan), and a water pump is
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.wikipedia.org/wiki/Ev aporativ e_cooler

Large hyperboloid cooling towersmade of structural steel for a power

plant in Kharkov (Ukraine)

Mist spraying system with waterpump beneath

used to wet the evaporative cooling pads. The cooling units can be mounted on the roof (down draft, ordownflow), or exterior walls or windows (side draft, or horizontal flow) of buildings. To cool, the fan drawsambient air through vents on the unit's sides and through the damp pads. Heat in the air evaporates water from the

pads which are constantly re-dampened to continue the cooling process. Then cooled, moist air is delivered into thbuilding via a vent in the roof or wall.

Because the cooling air originates outside the building, one or more large vents must exist to allow air to move frominside to outside. Air should only be allowed to pass once through the system, or the cooling effect will decrease.

This is due to the air reaching the saturation point. Often 15 or so air changes per hour (ACHs) occur in spacesserved by evaporative coolers, a relatively high rate of air exchange.

Evaporative (wet) cooling towers

Main article: Cooling tower

Cooling towers are structures for cooling water or other heat transfermedia to near-ambient wet-bulb temperature. Wet cooling towersoperate on the evaporative cooling principle, but are optimized to cool

the water rather than the air. Cooling towers can often be found on largebuildings or on industrial sites. They transfer heat to the environment fromchillers, industrial processes, or the Rankine power cycle, for example.

Misting systems

Misting systems work by forcing water via a high pressure pump andtubing through a brass and stainless steel mist nozzle that has an orifice ofabout 5 micrometres, thereby producing a micro-fine mist. The waterdroplets that create the mist are so small that they instantly flashevaporate. Flash evaporation can reduce the surrounding air temperature

by as much as 35 F (20 C) in just seconds.[12] For patio systems, it isideal to mount the mist line approximately 8 to 10 feet (2.4 to 3.0 m)above the ground for optimum cooling. Misting is used for applicationssuch as flowerbeds, pets, livestock, kennels, insect control, odor control,zoos, veterinary clinics, cooling of produce, and greenhouses.

Misting fans

A misting fan is similar to a humidifier. A fan blows a fine mist of waterinto the air. If the air is not too humid, the water evaporates, absorbingheat from the air, allowing the misting fan to also work as an air cooler. Amisting fan may be used outdoors, especially in a dry climate.

Small portable battery-powered misting fans, consisting of an electric fan and a hand-operated water spray pump,are sold as novelty items. Their effectiveness in everyday use is unclear.[citation needed]

Performance

Search Here
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Understanding evaporative cooling performance requires an understanding of psychrometrics. Evaporative coolingperformance is variable due to changes in external temperature and humidity level. A residential cooler should beable to cool air to within 34 C (57 F) of the corresponding wet-bulb temperature.

It is simple to predict cooler performance from standard weather report information. Because weather reportsusually contain the dewpoint and relative humidity, but not the wet-bulb temperature, a psychrometric chart or asimple computer program must be used to compute the wet bulb temperature. Once the wet bulb temperature andthe dry bulb temperature are identified, the cooling performance or leaving air temperature of the cooler may be

determined:

TLA = TDB ((TDB TWB) xE)TLA = Leaving Air TempTDB = Dry Bulb TempTWB = Wet Bulb Temp

E= Efficiency of the evaporative media.

Evaporative media efficiency usually runs between 80% to 90%, and the evaporation efficiency drops very littleover time. Typical aspen pads used in residential evaporative coolers offer around 85% efficiency while CELdektype of evaporative media offer efficiencies of >90% depending on air velocity. The CELdek media is more oftenused in large commercial and industrial installations.

As an example, in Las Vegas, Nevada, with a typical summer design day of 108F DB/66F WB or about 8%relative humidity, the leaving air temperature of a residential cooler would be:

TLA = 108 ((108 66) x 85% efficiency)TLA = 72.3F

However, either of two methods can be used to estimate performance:

Use a psychrometric chart to calculate wet bulb temperature, and then add 68 F as described above.Use a rule of thumb which estimates that the wet bulb temperature is approximately equal to the ambienttemperature, minus one third of the difference between the ambient temperature and the dew point. As

before, add 68 F as described above.

Some examples clarify this relationship:

At 32 C (90 F) and 15% relative humidity, air may be cooled to nearly 16 C (61 F). The dew point forthese conditions is 2 C (36 F).

At 32 C (90 F) and 50% relative humidity, air may be cooled to about 24 C (75 F). The dew point forthese conditions is 20 C (68 F).At 40 C (104 F) and 15% relative humidity, air may be cooled to nearly 21 C (70 F). The dew point fothese conditions is 8 C (46 F).

(Cooling examples extracted from the June 25, 2000 University of Idaho publication, "Homewise(http://info.ag.uidaho.edu/homewise/homewise_062500.htm) ").

Because evaporative coolers perform best in dry conditions, they are widely used and most effective in arid, deserregions such as the southwestern USA and northern Mexico.
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A misting fan

The same equation indicates why evaporative coolers are of limited use in highly humid environments: for examplea hot August day in Tokyo may be 30 C (86 F), 85% relative humidity, 1,005 hPa pressure. This gives dew poin27.2 C (81.0 F) and wet-bulb temperature 27.88 C (82.18 F). According to the formula above, at 85%efficiency air may be cooled only down to 28.2 C (82.8 F) which makes it quite impractical.

Comparison to air conditioning

Comparison of evaporative cooling to phase-change air conditioning:

Advantages

Less expensive to install

Estimated cost for installation is about half that of central

refrigerated air conditioning.[13]

Less expensive to operate

Estimated cost of operation is 1/4 that of refrigerated air.Power consumption is limited to the fan and water pump. Because the water vapor is not recycled, there isno compressor that consumes most of the power in closed-cycle refrigeration.The refrigerant is water. No special refrigerants, such as ammonia, sulfur dioxide or CFCs, are used thatcould be toxic, expensive to replace, contribute to ozone depletion and/or be subject to stringent licensingand environmental regulations.

Ease of maintenance

The only two mechanical parts in most basic evaporative coolers are the fan motor and the water pump, boof which can be repaired at low cost and often by a mechanically inclined homeowner.

Ventilation air

The constant and high volumetric flow rate of air through the building reduces the "age-of-air" in the buildingdramatically.Evaporative cooling increases humidity. In dry climates, this may improve comfort and decrease staticelectricity problems.The pad itself acts as a rather effective air filter when properly maintained; it is capable of removing a variety

of contaminants in air, including urban ozone caused by pollution, regardless of very dry weather.Refrigeration-based cooling systems lose this ability whenever there is not enough humidity in the air to keepthe evaporator wet while providing a constant trickle of condensate that washes out dissolved impuritiesremoved from the air.

Disadvantages

Performance

High dewpoint (humidity) conditions decrease the cooling capability of the evaporative cooler.
http://en.wikipedia.org/wiki/Ozonehttp://en.wikipedia.org/wiki/Static_electricityhttp://en.wikipedia.org/wiki/Humidityhttp://en.wikipedia.org/wiki/Ozone_depletionhttp://en.wikipedia.org/wiki/CFCshttp://en.wikipedia.org/wiki/Sulfur_dioxidehttp://en.wikipedia.org/wiki/Ammoniahttp://en.wikipedia.org/wiki/Gas_compressorhttp://en.wikipedia.org/wiki/Evaporative_cooler#cite_note-13http://en.wikipedia.org/wiki/Air_conditioninghttp://en.wikipedia.org/wiki/Wet-bulb_temperaturehttp://en.wikipedia.org/wiki/Tokyohttp://en.wikipedia.org/wiki/File:MistingFan.jpg


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No dehumidification. Traditional air conditioners remove moisture from the air, except in very dry locationswhere recirculation can lead to a buildup of humidity. Evaporative cooling adds moisture, but in dry climatedryness may improve thermal comfort at higher temperatures.

Comfort

The air supplied by the evaporative cooler is typically 8090% relative humidity; very humid air reduces theevaporation rate of moisture from the skin, nose, lungs, and eyes.

High humidity in air accelerates corrosion, particularly in the presence of dust. This can considerably shortenthe life of electronic and other equipment.High humidity in air may cause condensation of water. This can be a problem for some situations (e.g.,electrical equipment, computers, paper, books, old wood).

Water

Evaporative coolers require a constant supply of water to wet the pads.Water high in mineral content will leave mineral deposits on the pads and interior of the cooler. Depending othe type and concentration of minerals, possible safety hazards during the replacement and waste removal o

the pads could be present. Bleed-off and refill (purge pump) systems may reduce this problem.The water supply line may need protection against freeze bursting during off-season, winter temperatures.The cooler itself needs to be drained too, as well as cleaned periodically and the pads replaced.

Mosquitoes In India, an evaporative cooler is a common place for mosquito breeding. Indian authorities considera poorly maintained cooler to be a big threat to health. See Dengue and Coolers(http://www.thenewstribe.com/2011/08/20/dengue-can-spread-from-unclean-coolers/)

Miscellaneous

Odors and other outdoor contaminants may be blown into the building unless sufficient filtering is in place.Mold and bacteria may be dispersed into interior air from poorly maintained or defective systems, causingSick Building SyndromeAsthma patients may need to avoid poorly maintained evaporatively cooled environments.A sacrificial anode may be required to prevent excessive evaporative cooler corrosion.Wood wool of dry cooler pads can catch fire even by small sparks.

See also

Architectural engineeringBuilding engineeringCar coolerCooling towerDehumidifierHumidifierHVAC (Heating, ventilating and air conditioning)Pot-in-pot refrigerator
http://en.wikipedia.org/wiki/Pot-in-pot_refrigeratorhttp://en.wikipedia.org/wiki/HVAChttp://en.wikipedia.org/wiki/Humidifierhttp://en.wikipedia.org/wiki/Dehumidifierhttp://en.wikipedia.org/wiki/Cooling_towerhttp://en.wikipedia.org/wiki/Car_coolerhttp://en.wikipedia.org/wiki/Building_engineeringhttp://en.wikipedia.org/wiki/Architectural_engineeringhttp://en.wikipedia.org/wiki/Wood_woolhttp://en.wikipedia.org/wiki/Sacrificial_anodehttp://en.wikipedia.org/wiki/Asthmahttp://en.wikipedia.org/wiki/Sick_Building_Syndromehttp://www.thenewstribe.com/2011/08/20/dengue-can-spread-from-unclean-coolers/http://en.wikipedia.org/wiki/Mineralhttp://en.wikipedia.org/wiki/Condensationhttp://en.wikipedia.org/wiki/Corrosionhttp://en.wikipedia.org/wiki/Thermal_comforthttp://en.wikipedia.org/wiki/Dehumidifier


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10/.wikipedia.org/wiki/Ev aporativ e_cooler

References

1. ^ Kheirabadi, Masoud (1991).Iranian cities: formation and development. Autin, TX: University of Texas Press.p. 36. ISBN 978-0-292-72468-6.

2. ^ "Statistical Center of Iran > Home" (http://www.amar.org.ir/Default.aspx?tabid=133) (in Farsi). Teheran:Statistical Centere of Iran. http://www.amar.org.ir/Default.aspx?tabid=133. Retrieved 25 February 2012.

3. ^ John Zellweger (1906). "Air filter and cooler" (http://www.google.com/patents?

=04pHAAAAEBAJ&printsec=abstract&zoom=4&dq=cooling+excelsior&as_drrb_is=b&as_minm_is=1&as_miny_s=1799&as_maxm_is=1&as_maxy_is=1910&num=30#PPA2,M1) . U.S. patent 838602.http://www.google.com/patents?=04pHAAAAEBAJ&printsec=abstract&zoom=4&dq=cooling+excelsior&as_drrb_is=b&as_minm_is=1&as_miny_s=1799&as_maxm_is=1&as_maxy_is=1910&num=30#PPA2,M1.

4. ^ Bryant Essick (1945). "Pad for evaporative coolers" (http://www.google.com/patents?id=Z2BKAAAAEBAJ&pg=PA1&dq=excelsior+evaporative-cooler&as_drrb_is=b&as_minm_is=1&as_miny_is=1900&as_maxm_is=1&as_maxy_is=1950&num=30&rview=&source=gbs_selected_pages&cad=0_1#PPA1,M1) . U.S. patent 2391558. http://www.google.com/patents?id=Z2BKAAAAEBAJ&pg=PA1&dq=excelsior+evaporative-cooler&as_drrb_is=b&as_minm_is=1&as_miny_is=1900&as_maxm_is=1&as_maxy_is=1950&num=30&rview=

&source=gbs_selected_pages&cad=0_1#PPA1,M1.5. ^ Scott Landis (1998). The Workshop Book (http://books.google.com/books?

id=bs7I7qf5cUQC&pg=PA120&dq=evaporative+cooler+%22squirrel+cage%22+southwest+popular) . TauntonPress. p. 120. ISBN 978-1-56158-271-6. http://books.google.com/books?id=bs7I7qf5cUQC&pg=PA120&dq=evaporative+cooler+%22squirrel+cage%22+southwest+popular.

6. ^ Arthur William Gutenberg (1955). The Economics of the Evaporative Cooler Industry in the Southwestern UnitStates (http://books.google.com/books?id=uq1EAAAAIAAJ) . Stanford University Graduate School of Business.

p. 167. http://books.google.com/books?id=uq1EAAAAIAAJ.7. ^ Such units were mounted on the passenger-side window of the vehicle; the window was rolled nearly all the wa

up, leaving only enough space for the vent which carried the cool air into the vehicle.8. ^ AZEVAP: History of Evaporative Cooling Technology

(http://www.azevap.com/EvaporativeCooling/historytechnology.php)9. ^ www.1900s.org.uk: Food storage in a working class London household in the 1900s

(http://www.1900s.org.uk/1900s-food-storage.htm)10. ^ Gordon B. Bonan. Forests and Climate Change: Forcings, Feedbacks, and the Climate Benefits of Forests. 13

June 2008 Vol. 320 Science11. ^ see Independent Testing tab, Thermodynamic performance assessment of a novel air cooling cycle and other

papers http://www.coolerado.com/products /material-resource-center/12. ^ http://www.cool-off.com/faqs.html13. ^ John Krigger and Chris Dorsi (2004). Residential Energy: Cost Savings and Comfort for Existing Buildings

(http://books.google.com/books?id=7HlKF4trR-YC&pg=PA207&dq=evaporative+coolers+cost+install#v=onepage&q=evaporative%20coolers%20cost%20install&

f=false) (4th ed.). Saturn Resource Management. p. 207. ISBN 978-1-880120-12-5.http://books.google.com/books?id=7HlKF4trR-YC&pg=PA207&dq=evaporative+coolers+cost+install#v=onepage&q=evaporative%20coolers%20cost%20install&f=false.

External links

Holladay, April (2001). "A swamp cooler cools air by evaporation" (http://www.wonderquest.com/swampcoolers.htm) . WonderQuest Weekly Q&A science column. USAToday.com.
http://www.wonderquest.com/swamp-coolers.htmhttp://en.wikipedia.org/wiki/USATodayhttp://www.wonderquest.com/swamp-coolers.htmhttp://books.google.com/books?id=7HlKF4trR-YC&pg=PA207&dq=evaporative+coolers+cost+install#v=onepage&q=evaporative%20coolers%20cost%20install&f=falsehttp://en.wikipedia.org/wiki/Special:BookSources/978-1-880120-12-5http://en.wikipedia.org/wiki/International_Standard_Book_Numberhttp://books.google.com/books?id=7HlKF4trR-YC&pg=PA207&dq=evaporative+coolers+cost+install#v=onepage&q=evaporative%20coolers%20cost%20install&f=falsehttp://en.wikipedia.org/wiki/Evaporative_cooler#cite_ref-13http://www.cool-off.com/faqs.htmlhttp://en.wikipedia.org/wiki/Evaporative_cooler#cite_ref-12http://www.coolerado.com/products/material-resource-center/http://en.wikipedia.org/wiki/Evaporative_cooler#cite_ref-11http://en.wikipedia.org/wiki/Science_(journal)http://en.wikipedia.org/wiki/Evaporative_cooler#cite_ref-10http://www.1900s.org.uk/1900s-food-storage.htmhttp://en.wikipedia.org/wiki/Evaporative_cooler#cite_ref-9http://www.azevap.com/EvaporativeCooling/historytechnology.phphttp://en.wikipedia.org/wiki/Evaporative_cooler#cite_ref-8http://en.wikipedia.org/wiki/Evaporative_cooler#cite_ref-7http://books.google.com/books?id=uq1EAAAAIAAJhttp://books.google.com/books?id=uq1EAAAAIAAJhttp://en.wikipedia.org/wiki/Evaporative_cooler#cite_ref-6http://books.google.com/books?id=bs7I7qf5cUQC&pg=PA120&dq=evaporative+cooler+%22squirrel+cage%22+southwest+popularhttp://en.wikipedia.org/wiki/Special:BookSources/978-1-56158-271-6http://en.wikipedia.org/wiki/International_Standard_Book_Numberhttp://books.google.com/books?id=bs7I7qf5cUQC&pg=PA120&dq=evaporative+cooler+%22squirrel+cage%22+southwest+popularhttp://en.wikipedia.org/wiki/Evaporative_cooler#cite_ref-5http://www.google.com/patents?id=Z2BKAAAAEBAJ&pg=PA1&dq=excelsior+evaporative-cooler&as_drrb_is=b&as_minm_is=1&as_miny_is=1900&as_maxm_is=1&as_maxy_is=1950&num=30&rview=1&source=gbs_selected_pages&cad=0_1#PPA1,M1http://www.google.com/patents?id=Z2BKAAAAEBAJ&pg=PA1&dq=excelsior+evaporative-cooler&as_drrb_is=b&as_minm_is=1&as_miny_is=1900&as_maxm_is=1&as_maxy_is=1950&num=30&rview=1&source=gbs_selected_pages&cad=0_1#PPA1,M1http://en.wikipedia.org/wiki/Evaporative_cooler#cite_ref-4http://www.google.com/patents?=04pHAAAAEBAJ&printsec=abstract&zoom=4&dq=cooling+excelsior&as_drrb_is=b&as_minm_is=1&as_miny_is=1799&as_maxm_is=1&as_maxy_is=1910&num=30#PPA2,M1http://www.google.com/patents?=04pHAAAAEBAJ&printsec=abstract&zoom=4&dq=cooling+excelsior&as_drrb_is=b&as_minm_is=1&as_miny_is=1799&as_maxm_is=1&as_maxy_is=1910&num=30#PPA2,M1http://en.wikipedia.org/wiki/Evaporative_cooler#cite_ref-3http://www.amar.org.ir/Default.aspx?tabid=133http://www.amar.org.ir/Default.aspx?tabid=133http://en.wikipedia.org/wiki/Evaporative_cooler#cite_ref-2http://en.wikipedia.org/wiki/Special:BookSources/978-0-292-72468-6http://en.wikipedia.org/wiki/International_Standard_Book_Numberhttp://en.wikipedia.org/wiki/Evaporative_cooler#cite_ref-1


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http://www.wonderquest.com/swamp-coolers.htm. Retrieved 20060714.PATH Tech Inventory: Two Stage Evaporative Cooler(http://www.toolbase.org/Techinventory/TechDetails.aspx?ContentDetailID=789&BucketID=6&CategoryID=6)PATH Tech Inventory: Evaporative Cooler (http://www.toolbase.org/TechInventory/TechDetails.aspx?ContentDetailID=749&BucketID=1&CategoryID=6)Evaporative cooling simulation (http://www.colorado.edu/physics/2000/bec/evap_cool.html)

Coolerado indirect evaporative cooling (http://www1.eere.energy.gov/femp/pdfs/tir_coolerado.pdf)Air Conditioning Repair (http://dallas-air-conditioning-repair.net) Self Help Air Conditioning RepairInnovative Evaporative and Thermally Activated Technologies Improve Air Conditioning(http://www.nrel.gov/innovation/pdfs/47566.pdf)Evaporative Cooling in aircraft (http://www.flightglobal.com/pdfarchive/view/1934/1934%20-%201411.html) - explained in 1934Flight

Retrieved from "http://en.wikipedia.org/w/index.php?title=Evaporative_cooler&oldid=524262071"Categories: Psychrometrics Cooling technology Heating, ventilating, and air conditioning

This page was last modified on 21 November 2012 at 22:45.Text is available under the Creative Commons Attribution-ShareAlike License; additional terms may apply.See Terms of Use for details.Wikipedia is a registered trademark of the Wikimedia Foundation, Inc., a non-profit organization.
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