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Air cooling is a method of dissipating
heat In thermodynamics, heat is defined as the form of energy crossing the boundary of a thermodynamic system by virtue of a temperature difference across the boundary. A thermodynamic system does not ''contain'' heat. Nevertheless, the term is al ...
. It works by expanding the surface area or increasing the flow of air over the object to be cooled, or both. An example of the former is to add cooling fins to the surface of the object, either by making them integral or by attaching them tightly to the object's surface (to ensure efficient heat transfer). In the case of the latter, it is done by using a fan blowing air into or onto the object one wants to cool. The addition of fins to a
heat sink A heat sink (also commonly spelled heatsink) is a passive heat exchanger that transfers the heat generated by an electronic or a mechanical device to a fluid medium, often air or a liquid coolant, where it is dissipated away from the device, th ...
increases its total surface area, resulting in greater cooling effectiveness. There are two types of cooling pads that can used for air cooling: one is the honeycomb design and another one is
excelsior Excelsior, a Latin comparative word often translated as "ever upward" or "even higher", may refer to: Arts and entertainment Literature and poetry * "Excelsior" (Longfellow), an 1841 poem by Henry Wadsworth Longfellow * ''Excelsior'' (Macedo ...
. In all cases, the air has to be cooler than the object or surface from which it is expected to remove heat. This is due to the
second law of thermodynamics The second law of thermodynamics is a physical law based on universal experience concerning heat and Energy transformation, energy interconversions. One simple statement of the law is that heat always moves from hotter objects to colder objects ( ...
, which states that heat will only move spontaneously from a hot reservoir (the heat sink) to a cold reservoir (the air).


Derating at high altitude

When operating in an environment with lower air pressure like high altitude or airplane cabins, the cooling capacity has to be derated compared to that of sea level. A rule-of-thumb formula to note: 1 - (h/17500) = derating factor. Where ''h'' is the height over sea level in meters. And the result is the factor that should be multiplied with the cooling capacity in to get the cooling capacity at the specified height over sea level.ericsson.net - Forced air cooling of DC/DC power modules at high altitude, Design Note 025
table "Cooling efficiency"


See also

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Computer cooling Computer cooling is required to remove the waste heat produced by computer components, to keep components within permissible operating temperature limits. Components that are susceptible to temporary malfunction or permanent failure if over ...
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Computer fan A computer fan is any fan inside, or attached to, a computer case used for active cooling. Fans are used to draw cooler air into the case from the outside, expel warm air from inside and move air across a heat sink to cool a particular compon ...
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Deep water air cooling Deep water source cooling (DWSC) or deep water air cooling is a form of air cooling for process and comfort space cooling which uses a large body of naturally cold water as a heat sink. It uses water at 4 to 10 degrees Celsius drawn from deep area ...
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Evaporative cooling An evaporative cooler (also known as evaporative air conditioner, swamp cooler, swamp box, desert cooler and wet air cooler) is a device that cools air through the evaporation of water. Evaporative cooling differs from other air conditioning s ...
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Water cooling Cooling tower and water discharge of a nuclear power plant Water cooling is a method of heat removal from components and industrial equipment. Evaporative cooling using water is often more efficient than air cooling. Water is inexpensive and non ...
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Oil cooling Oil cooling is the use of engine oil as a coolant, typically to remove surplus heat from an internal combustion engine. The hot engine transfers heat to the oil which then usually passes through a heat-exchanger, typically a type of radiator kn ...
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Heat pipe A heat pipe is a heat-transfer device that employs phase transition to transfer heat between two solid interfaces. At the hot interface of a heat pipe, a volatile liquid in contact with a thermally conductive solid surface turns into a vapor b ...
cooling *
Peltier Peltier is a French surname. Notable people with the surname include: * Autumn Peltier (born 2004), climate activist * Harvey Peltier, Jr. (1923-1980), American politician *Harvey Peltier, Sr. (1899-1977), American politician *Jean Charles Athanase ...
cooling *
Heater core A heater core is a radiator-like device used in heating the cabin of a vehicle. Hot coolant from the vehicle's engine is passed through a winding tube of the core, a heat exchanger between coolant and cabin air. Fins attached to the core tubes ser ...


References

* *P V Lamarque, "The design of cooling fins for Motorcycle Engines", Report of the Automobile Research Committee, Institution of Automobile Engineers Magazine, March 1943 issue, and also in "The Institution of Automobile Engineers Proceedings, Session 1942-1943, pp 99-134 and 309-312. *Julius Mackerle, "Air-Cooled Motor Engines". Charles Griffin & Company Ltd., London 1972 *Anish Gokhale et al.: "Optimization of Engine Cooling through Conjugate Heat Transfer Simulation and Analysis of Fins"; SAE Paper 2012-32-0054 {{Automotive engine , collapsed Engine cooling systems Cooling technology Computer hardware cooling