A set of 4 industry standard 80mm fans, most commonly used in personal computers.

A computer fan can be any fan inside a computer case used for cooling purposes, and may refer to fans that draw cooler air into the case from the outside, expel warm air from inside, or move air across a heatsink to cool a particular component. The use of fans and/or other hardware to cool a computer is sometimes referred to as active cooling. Image File history File links Size of this preview: 800 × 600 pixelsFull resolution (1280 × 960 pixel, file size: 173 KB, MIME type: image/jpeg) File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ... Image File history File links Size of this preview: 800 × 600 pixelsFull resolution (1280 × 960 pixel, file size: 173 KB, MIME type: image/jpeg) File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ... A millimetre (American spelling: millimeter, symbol mm) is an SI unit of length that is equal to one thousandth of a metre. ... It has been suggested that this article be split into multiple articles accessible from a disambiguation page. ... A tower case featuring a modern design. ... A large copper heatsink. ... Many components in a computer system unit produce large amout of heat during operation, including, but not limited to: the CPU, chipset, graphics card, and hard drives. ...

Akasa, Arctic Cooling, Delta, Nexus, Noctua, NorthQ, PAPST, Zalman are brands of fans. Akasas Corporate logo The correct title of this article is . ... Arctic Cooling is a maker of coolers for computer components, most notably heatsinks and fans. ... The Zalman flower copper cpu heatsink A Zalman 7000 for Pentium 4 and Athlon 64 microprocessors Zalman Tech Co. ...

Usage

As processors, graphics cards, RAM and other components in computers have increased in clock speed and power consumption, the amount of heat produced by these components as a side-effect of normal operation has also increased. The temperatures of these components need to be kept within a reasonable range to prevent overheating, instability, malfunction and damage leading to a shortened component lifespan. CPU can stand for: in computing: Central processing unit in journalism: Commonwealth Press Union in law enforcement: Crime prevention unit in software: Critical patch update, a type of software patch distributed by Oracle Corporation in Macleans College is often known as Ash Lim. ... A graphics/video/display card/board/adapter is a computer component designed to convert the logical representation of visual information into a signal that can be used as input for a display medium. ... Look up RAM, Ram, ram in Wiktionary, the free dictionary. ... In synchronous digital electronics, such as most computers, a clock signal is a signal used to coordinate the actions of two or more circuits. ...

While in earlier personal computers it was possible to cool most components using convection (passive cooling), more efficient cooling has become a necessity on many components. To cool these components, fans are used to move heated air away from the components and draw cooler air over them. Fans attached to components are usually used in combination with a heatsink to increase the surface area available for heat conduction, thereby improving the efficiency of cooling. Convection in the most general terms refers to the internal movement of currents within fluids (i. ... A large copper heatsink. ...

In the IBM compatible PC market, the computer's PSU (power supply unit) has always used an exhaust fan to expel warm air from the PSU. Active cooling on CPUs started to appear on the retail Intel Pentium (released in 1993), and by 1997 was standard on all desktop processors^[1]. Chassis or case fans, usually one exhaust fan to expel heated air from the rear and optionally an intake fan to draw cooler air in through the front, became common with the arrival of the Pentium 4 in late 2000^[1]. A third vent fan in the side of the PC, often located over the CPU, is also common. The GPU (graphics processing unit) on many modern graphics cards requires a heatsink and fan. In some cases, the northbridge chip on the motherboard requires a fan and heatsink. Other components such as the RAM and hard drives may also be actively cooled, though as of 2007 this remains relatively unusual. It is not uncommon to find five or more fans in a modern PC. The most common RAM cooling application are RAM Heatsinks, which attach to the RAM itself. [1] This article or section does not cite its references or sources. ... A wall wart style variable DC power supply with its cover removed. ... Intel Corporation (NASDAQ: INTC, SEHK: 4335), founded in 1968 as Integrated Electronics Corporation, is an American multinational corporation that is best known for designing and manufacturing microprocessors and specialized integrated circuits. ... This article does not cite any references or sources. ... The Pentium 4 brand refers - since 2000 - to Intels mainstream desktop and mobile single-core CPUs with the seventh-generation NetBurst architecture, which was the companys first all-new design since the Intel P6 of the Pentium Pro branded CPUs of 1995. ... GPU may stand for: Graphics processing unit, a special stream processor used in computer graphics hardware Gosudarstvennoye Politicheskoye Upravlenie (Главное Политическое Управление, or Main Political Directorate) of the Red Army, responsible for troops morale and propaganda. ... This article or section does not cite any references or sources. ... A motherboard is the central or primary circuit board making up a complex electronic system, such as a modern computer. ... Typical hard drives of the mid-1990s. ... 2007 is a common year starting on Monday of the Gregorian calendar. ...

Cooling fan applications

A 120 mm 4 LED blue case fan

An 80 mm computer fan.

Image File history File linksMetadata Download high resolution version (2048x1536, 1256 KB) Licensing I, the creator of this work, hereby grant the permission to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1. ... Image File history File linksMetadata Download high resolution version (2048x1536, 1256 KB) Licensing I, the creator of this work, hereby grant the permission to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1. ... External links LEd Category: TeX ... Image File history File links Protechnic80mmfan. ... Image File history File links Protechnic80mmfan. ...

Case mount

Used to aerate the case of the computer. The components inside the case which use active cooling cannot remove heat efficiently if the surrounding air is too hot. Case fans move air through the case, usually drawing cooler outside air in through the front (where it may also be drawn over the internal hard drive racks) and expelling it through the rear. There may be a third fan in the side or top of the case to draw outside air into the vicinity of the CPU, which is usually the largest single generator of heat. Case fans are usually 80 mm, 92 mm or 120 mm along each side. Because case fans are often the most readily visible form of cooling on a PC, decorative fans are widely available and may be lit with LEDs or made of UV-reactive plastic. Decorative grilles are also common. Decorative fans and accessories are popular with case modders. Air filters are often used over intake fans, to prevent dust from entering the case. External links LEd Category: TeX ... Note: Ultraviolet is also the name of a 1998 UK television miniseries about vampires. ... This article does not cite any references or sources. ... Look up dust in Wiktionary, the free dictionary. ...

Power Supply fan

A power supply (PSU) fan often plays a double role, not only keeping the PSU itself from overheating, but also removing warm air from inside the case. Many modern PSUs expel the air from the rear, but only from the PSU itself. PSUs with two fans are also available, which have a large fan on the bottom for removing case air and a smaller one on the back for expelling the warm air at a faster rate. A wall wart style variable DC power supply with its cover removed. ...

CPU fan

Used to cool the CPU (central processing unit). CPU can stand for: in computing: Central processing unit in journalism: Commonwealth Press Union in law enforcement: Crime prevention unit in software: Critical patch update, a type of software patch distributed by Oracle Corporation in Macleans College is often known as Ash Lim. ...

See computer spot cooling.

Computer cooling is the practice of relieving heat, a potentially damaging byproduct of operation, from electronic computers. ...

Graphics card fan

Used to cool the GPU and/or memory on graphics cards. These fans were not necessary on older cards because of their low heat dissipation, but most modern graphics cards, especially those designed for 3D graphics and gaming, need their own dedicated cooling fans. Some of the higher powered cards can produce more heat than the CPU (over 140 watts^[2]), so efficient cooling is especially important. Passive coolers for new video cards, however, are not unheard of, notably the Thermalright HR-03 among others. GPU may stand for: Graphics processing unit, a special stream processor used in computer graphics hardware Gosudarstvennoye Politicheskoye Upravlenie (Главное Политическое Управление, or Main Political Directorate) of the Red Army, responsible for troops morale and propaganda. ... A GeForce 4 4200-based graphics card A graphics card or video card is a component of a computer which is designed to convert a logical representation of an image stored in memory to a signal that can be used as input for a display medium, most often a monitor... The watt (symbol: W) is the SI derived unit of power, equal to one joule per second. ... Thermalright is a company that manufactures high-performance heat sinks for desktop computers. ...

Chipset fan

Used to cool the northbridge of a motherboard's chipset or for system bus overclocking. A chipset is a group of integrated circuits (chips) that are designed to work together, and are usually marketed as a single product. ... Front Side Bus (FSB) is the term used to describe the CPU data bus. ... AMD Athlon XP Overclocking BIOS Setup on ABIT NF7-S. FSB frequency (External clock) has increased from 133 MHz to 148 MHz, and clock multiplier factor has changed from 13. ...

Other types of fans

Other less commonly encountered fans may include:

• PCI slot fan: A fan mounted in one of the PCI slots, usually to supply additional cooling to the PCI and/or graphics cards.
• Hard disk fan: A fan mounted next to or on a hard disk drive. This may be desirable on faster-spinning (e.g. 10,000 RPM) hard disks where heat production is higher.

64-bit PCI expansion slots inside a Power Macintosh G4 The Peripheral Component Interconnect, or PCI Standard (in practice almost always shortened to PCI), specifies a computer bus for attaching peripheral devices to a computer motherboard. ...

Physical characteristics

The width and height of these usually square fans are measured in millimeters, with common sizes including 60 mm, 80 mm, 92 mm and 120 mm. Round fans are also available; these are usually designed so that one may use a larger fan than the mounting holes would otherwise allow (i.e., a 120mm fan with 90mm holes). The amount of airflow which these fans generate is measured in cubic-feet per minute (CFM), and the speed of rotation is measured in revolutions per minute (RPM). Often, computer enthusiasts choose fans which have a higher CFM rating, but produce less noise (measured in decibels, or dB), and some fans come with an adjustable RPM rating to produce less noise if the computer does not need much airflow. Fan speeds may be controlled manually (a simple potentiometer control, for example), by the computer hardware or by software. For other uses, see Revolutions per minute (disambiguation). ... The decibel (dB) is a logarithmic unit of measurement that expresses the magnitude of a physical quantity (usually power) relative to a specified or implied reference level. ... The present popular usage of the term potentiometer (or pot for short) describes an electrical device which has a user-adjustable resistance. ...

The type of bearing used in a fan can affect its performance and noise output. Most computer fans use one of the following bearing types: A bearing is a device to permit constrained relative motion between two parts, typically rotation or linear movement. ...

• Sleeve bearing fans use two surfaces lubricated with oil or grease as a friction contact. Sleeve bearings are less durable as the contact surfaces can become rough and/or the lubricant dry up, eventually leading to failure. Sleeve bearings can fail at higher temperatures, and may perform poorly when mounted in any orientation other than horizontally. The lifespan of a sleeve bearing fan may be around 40,000 hours at 50°C. Fans that use sleeve bearings are generally cheaper and quieter than fans that use ball bearings.^[3]
• Ball bearing' fans use a sealed bearing containing steel balls against which the axle rotates. Though generally more expensive and noisier, ball bearing fans do not suffer the same orientation limitations as sleeve bearing fans, and can be more durable, especially at higher temperatures. The lifespan of a ball bearing fan may be around 63,000 hours at 50°C.^[3]
• Fluid bearing fans have the advantages of silent operation and high life expectancy (comparable to ball bearing fans). However, these fans tend to be the most expensive.
• Magnetic bearing or Maglev fans, in which the fan is repelled from the motor by magnetism.

A 4 point angular contact ball bearing A ball bearing is a common type of rolling-element bearing, a kind of bearing. ... Fluid bearings are bearings which solely support the bearings loads on a thin layer of liquid or gas. ... A magnetic bearing is a bearing which supports a load using magnetic levitation. ...

Connector pin assignment

The behaviour of a PWM fan plugged into a 3-pin header (i.e. PWM signal disconnected) varies depending on model. Intel CPU coolers run at their fastest speed, as a failsafe (but can be slowed by connecting pins 4-1); others may run at the lowest speed (but can be operated at the fastest speed by joining pins 4-2) [2] Pulse-width modulation of a signal or power source involves the modulation of its duty cycle, to either convey information over a communications channel or control the amount of power sent to a load. ...

Alternatives

If a fan is not desirable, because of noise or reliability concerns, there are some alternatives:

• Underclock/under-volt to reduce power dissipation (this is the inverse of the "diminishing returns" problem faced by overclockers)
• Larger heatsink (for example, some motherboards have northbridge fans; others have larger, more costly heatsinks)
• Convection cooling: carefully designed, correctly oriented, and sufficiently large CPU coolers can dissipate up to 100W by convection alone.
• More unusual solutions, e.g. heatpipes bonded to the metal case, water cooling.

See also

• Fan
• Centrifugal fan
• Computer cooling
• PC fan control
• Quiet PC

It has been suggested that this article be split into multiple articles accessible from a disambiguation page. ... Figure 1: Components of a centrifugal fan A centrifugal fan is a mechanical device for moving air or other gases. ... Computer cooling is the practice of relieving heat, a potentially damaging byproduct of operation, from electronic computers. ... Fan control is the management of the rotational speed of an electric fan, typically a computer fan, to provide adequate cooling while lowering noise. ... A quiet PC is a personal computer that makes little noise. ...

References

For the Manfred Mann album, see 2006 (album). ... is the 192nd day of the year (193rd in leap years) in the Gregorian calendar. ... Year 2007 (MMVII) is now the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era. ... is the 99th day of the year (100th in leap years) in the Gregorian calendar. ...

External links

• 4-Wire Pulse Width Modulation (PWM) Controlled Fans Revision 1.3