Product type
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Fan. A classic fan is a motor with blades that provides air flow; This also includes sets of several fans. In any case, such devices should not be confused with coolers (see below) - fans do not have radiators. Almost all solutions of this type are designed for cases (see “Purpose”), only a few models are designed for “airflow” hard drives or chipsets.
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Reversible fan. A type of fan (see above) in which the impeller is turned in the opposite direction. This was done so that when placed behind the “system unit” case or in its upper part, it was possible to give the assembly an aesthetic appearance - the reversible fan will be installed with the front side for air airflow. Such solutions are used mainly for the side walls of “aquarium” type housings.
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Radiator. Design made of heat-conducting material with a special ribbed shape. This shape provides a large area of contact with air, and as a result, good heat transfer. Radiators do not consume energy and operate absolutely silently, but are not very efficient. Therefore, in their pure form they are extremely rare, and such models are intended either for low-power PC components with low heat dissipation (energy-efficient processors, hard drives, etc.), or for assembling an active cooler (see below) from a separately purchased fan and radiator (this option is found among solutions for video cards).
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— Active cooler. A device in the form of a radiator with a fan installed on it; Moreover, in many models, the radiator does not directly contact the cooled component, but is connected to it using heat pipes, while air is blown out to the side (the so-called tower layout, especially popular in systems for CPU; for more details, see “Blowing air flow”) . In any case, such designs, on the one hand, are relatively simple and inexpensive, on the other hand, they are quite effective, making them an extremely popular type of CO. In particular, it is in this format that most solutions for processors are produced (including tower and boxed ones), and in general, coolers can be used for almost any component of the system, with the exception of the case.
- Water cooling. Water cooling systems consist of three main parts: a water block in direct contact with the component to be cooled (usually the processor), an external cooler, and a pump (either separate or built into the cooler). These components are connected by hoses through which water (or another similar coolant) circulates - it provides heat transfer. And the cooling unit is usually a cooler - a system of fans and radiators that dissipates thermal energy into the surrounding air. Water systems are noticeably more efficient than active coolers (see above); they are suitable even for very powerful and “hot” CPUs, which traditional coolers have difficulty coping with. On the other hand, this type of cooling is quite cumbersome and difficult to install, and is not cheap.
— LSS kit. Kit for self-assembly of a liquid (water) cooling system. In this case, it is understood that the entire system is supplied in the form of a set of parts, from which the customer must assemble the finished life-support system himself. Its installation is more complex than traditional water systems. Therefore, there are only a few LSS kits produced, and they are designed mainly for enthusiasts who like to experiment with the design and design of their PCs.
- Backplate. A solid metal plate used as a fastening element for the cooling system. Serves to prevent bending of the motherboard or video card when deploying a heat dissipation system, and also provides passive cooling of the rear side of tech modules with which it is adjacent.
— Water block VRM. A water block that provides effective cooling of the elements of the VRM (Voltage Regulator Module) power subsystem of the central processor.
— CPU water block. A copper or nickel heat exchanger designed to remove heat from the CPU through the coolant. Used in water cooling systems for computers. Most often, processor water blocks are equipped with mounts for specific processor platforms.
- GPU water block. Liquid cooling units for maximum efficient heat removal from the video card. Similar solutions are produced for a specific group of video cards on one graphics processor. GPU water blocks consist of two main parts: the top, where a copper alloy heat sink is located, a plastic cover with liquid channels and a casing to give rigidity to the structure, as well as a metal plate at the bottom of the block on the back side of the printed circuit board.
— A set of fastenings. A set of fasteners for mounting cooling systems on elements of a computer motherboard. Available for specific socket versions.Fan size
The diameter of the fan(s) used in the cooling system.
In general, larger fans are considered more advanced than smaller ones: they allow you to create a powerful air flow at a relatively low speed and low noise level. On the other hand, a large diameter means large dimensions, weight and price. As for specific figures,
40 mm and
60 mm models are considered miniature,
80 mm and
92 mm are medium,
120 mm and
135 /
140 mm are large, and even
200 mm fans are found in the most powerful
case systems.
Bearing
The type of bearing used in the cooling fan(s).
The bearing is the piece between the rotating axle of the fan and the fixed base that supports the axle and reduces friction. The following types of bearings are found in modern fans:
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Sliding. The action of these bearings is based on direct contact between two solid surfaces, carefully polished to reduce friction. Such devices are simple, reliable and durable, but their efficiency is rather low — rolling, and even more so the hydrodynamic and magnetic principle of operation (see below), provide much less friction.
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Rolling. They are also called "ball bearings", since the "intermediaries" between the axis of rotation and the fixed base are balls (less often — cylindrical rollers) fixed in a special ring. When the axis rotates, such balls roll between it and the base, due to which the friction force is very low — noticeably lower than in plain bearings. On the other hand, the design turns out to be more expensive and complex, and in terms of reliability it is somewhat inferior to both the same plain bearings and more advanced hydrodynamic devices (see below). Therefore, although rolling bearings are quite widespread nowadays, however, in general, they are much less common than the mentioned varieties.
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Hydrodynamic. Bearings of this type are filled with a special liquid; when rotate
...d, it creates a layer on which the moving part of the bearing slides. In this way, direct contact between hard surfaces is avoided and friction is significantly reduced compared to previous types. Also, these bearings are quiet and very reliable. Of their shortcomings, a relatively high cost can be noted, but in fact this moment often turns out to be invisible against the background of the price of the entire system. Therefore, this option is extremely popular nowadays, it can be found in cooling systems of all levels — from low-cost to advanced.
— Magnetic centering. Bearings based on the principle of magnetic levitation: the rotating axis is "suspended" in a magnetic field. Thus, it is possible (as in hydrodynamic ones) to avoid contact between solid surfaces and further reduce friction. Considered the most advanced type of bearings, they are reliable and quiet, but expensive.Max. RPM
The highest speed at which the cooling system fan is capable of operating; for models without a speed controller (see below), this item indicates the nominal rotation speed. In the "slowest" modern fans, the maximum speed
does not exceed 1000 rpm, in the "fastest" it can be up
to 2500 rpm and even
more.
Note that this parameter is closely related to the fan diameter (see above): the smaller the diameter, the higher the speed must be to achieve the desired airflow values. In this case, the rotation speed directly affects the level of noise and vibration. Therefore, it is believed that the required volume of air is best provided by large and relatively "slow" fans; and it makes sense to use "fast" small models where compactness is crucial. If we compare the speed of models of the same size, then higher speeds have a positive effect on performance, but increase not only the noise level, but also the price and power consumption.
Speed controller
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Auto (PWM). A type of automatic regulator used in processor cooling systems. The principle of this adjustment is that the automation monitors the current load on the CPU and adjusts the fan operation mode to it. Thus, the cooling system works "in advance": it actually prevents the temperature rise, and does not eliminate it (unlike the thermostat described below). The disadvantages of such automation are the high cost and additional compatibility requirements: the PWM function must be supported by the motherboard, and the fan must be powered through a 4-pin connector (see "Power").
— Manual. Manual regulator that allows you to set the rotation speed at the request of the user. Its main advantages are both the possibility of arbitrary adjustment and reliability: automation does not always respond optimally, and in performant systems it is sometimes better for the user to take control into his own hands. On the other hand, manual control is more expensive and also more difficult to use — it requires the user to pay more attention to the state of the system, and if not attentive, the likelihood of overheating increases significantly.
— Manual / auto. A combination of the two systems described above: the main control is carried out by PWM, and the manual regulator serves to limit the maximum rotational speed. A fairly convenient and advanced option that expands the possibilities of auto-adjustment and at the same time doe
...s not require constant temperature control, as with a purely manual setting. However such functionality is expensive.
— Adapter (resistor). In this case, the speed is adjusted by reducing the voltage supplied to the fan. To do this, it is connected to the power supply through a resistor adapter. This is a kind of alternative to manual adjustment: adapters are inexpensive. On the other hand, they are much less convenient: the only way to change the rotation speed with such an adjustment is to actually change the adapter, and for this you have to turn off the system and climb into the case.
— Thermostat. Automatic speed control according to data from a sensor that measures the temperature of the cooled component: when the temperature rises, the intensity of work also increases, and vice versa. Such systems are simpler than the PWMs described above, moreover, they can be used for almost any system component, not only for CPU. On the other hand, they have more inertia and reaction time: if the PWM prevents heating in advance, then the thermostat is triggered by an increase in temperature that has already happened.Max. air flow
The maximum airflow that a cooling fan can create; measured in CFM — cubic feet per minute.
The higher the CFM number, the more efficient the fan. On the other hand, high performance requires either a large diameter (which affects the size and cost) or high speed (which increases the noise and vibration levels). Therefore, when choosing, it makes sense not to chase the maximum air flow, but to use special formulas that allow you to calculate the required number of CFM depending on the type and power of the cooled component and other parameters. Such formulas can be found in special sources. As for specific numbers, in the most modest systems, the performance
does not exceed 30 CFM, and in the most powerful systems it can be up to 80 CFM and even
more.
It is also worth considering that the actual value of the air flow at the highest speed is usually lower than the claimed maximum; see Static Pressure for details.
MTBF
The total time that a cooling fan is guaranteed to run before it fails. Note that when this time is exhausted, the device will not necessarily break — many modern fans have a significant margin of safety and are able to work for some more period. At the same time, it is worth evaluating the overall durability of the cooling system according to this parameter.
replaceable
The ability
to replace a regular fan by the user himself — without contacting a service centre or repairmen. The maximum that may be required for such a procedure is the simplest tools like a screwdriver; sometimes they are even initially included in the cooling system kit.
The fan, as the most mobile part of any cooling system, is more prone to breakdowns and failures than other parts. In cases like this, it's cheaper (and often smarter) to replace just that part rather than buying a whole new system. Also, if desired, you can change a working fan — for example, to a more powerful or less noisy one.
Noise level
The standard noise level generated by the cooling system during operation. Usually, this paragraph indicates the maximum noise during normal operation, without overloads and other "extreme".
Note that the noise level is indicated in decibels, and this is a non-linear value. So it is easiest to evaluate the actual loudness using comparative tables. Here is a table for values found in modern cooling systems:
20 dB — barely audible sound (quiet whisper of a person at a distance of about 1 m, sound background in an open field outside the city in calm weather);
25 dB — very quiet (normal whisper at a distance of 1 m);
30 dB — quiet (wall clock). It is this noise that, according to sanitary standards, is the maximum allowable for constant sound sources at night (from 23.00 to 07.00). This means that if the computer is planned to sit at night, it is desirable that the volume of the cooling system does not exceed this value.
35 dB — conversation in an undertone, sound background in a quiet library;
40 dB — conversation, relatively quiet, but already in full voice. The maximum permissible noise level for residential premises in the daytime, from 7.00 to 23.00, according to sanitary standards. However, even the noisiest cooling systems usually do not reach this indicator, the maximum for such equipment is about 38 – 39 dB.