Introduction
Don't you think the term "liquid cooling" is suggestive of cars? In fact, liquid cooling is an integral part of a conventional engine. internal combustion almost 100 years old. The question immediately arises: why is it the preferred method of cooling expensive car engines? Why is liquid cooling so great?
To find out, we have to compare it to air cooling. When comparing the effectiveness of these cooling methods, two of the most important properties need to be considered: thermal conductivity and specific heat.
Thermal conductivity is a physical quantity that indicates how well a substance transfers heat. The thermal conductivity of water is almost 25 times that of air. Obviously, this gives water cooling a huge advantage over air cooling, as it transfers heat from a hot engine to a radiator much faster.
Specific heat is another physical quantity that is defined as the amount of heat required to raise the temperature of one kilogram of a substance by one kelvin (degree Celsius). The specific heat capacity of water is almost four times that of air. This means that heating water requires four times more energy than heating air. Again, the ability of water to absorb much more thermal energy without raising its own temperature is a huge advantage.
So, we have indisputable facts that liquid cooling is more efficient than air cooling. However, it is not at all necessary that it is - best method for cooling PC components. Let's figure it out.
PC liquid cooling
Despite the very good qualities heat dissipation, there are several good reasons not to put water in your computer. The most important of these reasons is the electrical conductivity of the coolant.
If you accidentally spilled a glass of water on a gasoline engine while refueling a radiator, then nothing terrible would have happened; water would not damage the engine. But if you poured a glass of water on the motherboard of your computer, it would be very bad. Therefore, there is a certain risk associated with the use of water to cool computer components.
The next factor is the complexity of maintenance. Air cooling systems are easier and cheaper to manufacture and repair than water-based counterparts, and radiators do not require any maintenance except for dust removal. Water cooling systems are much more difficult to work with. They are more difficult to install and often require little maintenance, albeit minor.
Third, PC water cooling components cost much more than air cooling components. If a set of high-quality radiators and air cooling fans for a processor, video card and motherboard will most likely cost around $ 150, then the cost of a liquid cooling system for the same components can easily go up to $ 500.
With so many shortcomings, water cooling systems, it would seem, should not be in demand. But in fact, they dissipate heat so well that this property justifies all the disadvantages.
There are ready-to-install liquid cooling systems on the market that are no longer the kit of spare parts that enthusiasts have had to deal with in the past. Complete systems are assembled, tested and completely reliable. In addition, water cooling is not as dangerous as it seems: of course, there is always a great risk when using liquids in a PC, but if you are careful, this risk is significantly reduced. When it comes to maintenance, modern refrigerants rarely need to be replaced, maybe once a year. When it comes to price, any piece of hardware that runs at high performance always costs more than usual, whether it's a Ferrari in your garage or a water cooling system for your computer. High performance comes at a price.
Suppose that you are attracted to this cooling method, or at least want to know how it works, what is involved with it, and what are its benefits.
General principles water cooling
The purpose of any cooling system in a PC is to remove heat from the components of the computer.
A traditional CPU air cooler removes heat from the CPU to the heatsink. The fan actively drives air through the fins of the radiator, and when the air passes by, it picks up heat. Air from the computer case is removed by another fan or even several. As you can see, the air moves a lot.
In water cooling systems, instead of air, a cooling liquid (heat carrier) is used to remove heat. The water comes out of the tank through a tube, going where it needs to be. The water cooling unit can either be a separate unit outside the PC case, or it can be integrated into the case. In the diagram, the water cooling unit is external.
Heat is transferred from the processor to the cooling head (water block), which is a hollow heat sink with an inlet and outlet for coolant. When water passes through the head, it takes heat with it. Heat transfer due to water is much more efficient than due to air.
The heated liquid is then pumped into the reservoir. From the reservoir, it flows into the heat exchanger, where it gives off heat to the radiator, and that to the ambient air, usually with the help of a fan. After that, water enters the head again and the cycle starts over.
Now that we have a good understanding of the basics of PC liquid cooling, let's talk about which systems are available on the market.
Choosing a water cooling system
There are three main types of water cooling systems: internal, external, and embedded. The main difference between the two is where their main components are located in relation to the computer case: radiator / heat exchanger, pump and reservoir.
As the name suggests, the built-in cooling system is part of PC case, that is, it is built into the case and is sold complete with it. Since the entire water cooling system is housed in the case, this option is probably the easiest to use, because there is more space inside the case and there are no bulky structures outside. The downside, of course, is that if you decide to upgrade to such a system, the old PC case will be useless.
If you love your PC case and don't want to part with it, then internal and external water cooling systems are likely to be more attractive. The components of the internal system are placed inside the PC case. Since most cases are not designed to accommodate such a cooling system, it becomes quite crowded inside. However, the installation of such systems will allow you to keep your favorite case, as well as carry it without any particular obstacles.
The third option is an external water cooling system. It is also for those who wish to keep their old PC case. In this case, the radiator, reservoir and water pump are placed in a separate unit outside the computer case. Water is pumped through pipes into the PC case, to the cooling head, and through the return pipe, the heated liquid is pumped out of the case into the reservoir. The advantage of the external system is that it can be used with any enclosure. It also allows for a larger radiator and may have better cooling capacity than the average built-in installation. The disadvantage is that a computer with an external cooling system is not as mobile as one with internal or built-in cooling systems.
In our case, portability does not really matter, but we would like to keep our "native" PC case. In addition, we were attracted by the increased cooling efficiency of the external radiator. Therefore, we chose an external cooling system for this review. Koolance has kindly provided us with an excellent example - the EXOS-2 system.
External water cooling system Koolance EXOS-2.
EXOS-2 is a powerful external water cooling system with a cooling capacity of over 700W. This does not mean that the system draws 700 watts - it only consumes a fraction of that. This means that the system can efficiently handle 700W of heat while maintaining the temperature at 55 degrees Celsius in a 25 degree environment.
EXOS-2 is supplied with all necessary tubes and fixtures, except for cooling heads (water blocks). The user will have to buy the right heads, depending on which PC components he wants to cool.
Cooling multiple components
One of the advantages of most liquid cooling systems is that they are expandable and can cool not only the processor but also other components. Even after passing through the CPU cooling head, the water is still able to cool, for example, the motherboard chipset and the graphics card. This is basic, but you can add even more components if you wish, such as a hard drive. To do this, each component that will be cooled will need its own water block. Of course, you also have to do some planning to make sure the coolant is flowing well.
Why is it beneficial to combine all three components - CPU, chipset, and graphics card - with a good water cooling system?
Most users understand the need for CPU cooling. The CPU gets very hot inside the PC case, and the stable performance of the computer depends on keeping the CPU temperature low. The CPU is one of the most expensive parts of a computer, and the lower the supported temperature, the longer the CPU will last. Finally, cooling the processor is especially important when overclocking.
CPU water block and assembly accessories.
The idea of \u200b\u200bcooling the motherboard chipset (or rather, the north bridge) may not be familiar to everyone. But keep in mind that a computer is as stable as its chipset is. In many cases, additional chipset cooling can contribute to system stability, especially when overclocked.
Chipset waterblock and assembly accessories.
The third component is very important for those who have a higher-end graphics card and use a PC for gaming. In many cases, the GPU on a video card generates more heat than the rest of the computer. Again, the better the GPU is cooled, the longer it will last, the better stability and more overclocking options.
Of course, for those users who do not intend to use their computer for gaming and have a low-powered graphics card, water cooling will be overkill. But for today's powerful and hotter graphics cards, water cooling can be a bargain.
We are going to install a cooling system on our Radeon X1900 XTX graphics card. Although this video card is not the newest and most powerful, it is still everywhere, and besides, it gets very hot. In the case of this model, Koolance offers not only a water block for the GPU / memory, but also a separate cooling head for the voltage regulator.
GPU Waterblock and Build Accessories.
If air cooling systems can keep the GPU temperature within acceptable limits, then we are not aware of such systems that can handle the extremely high temperatures of the voltage regulators on the X1900, which can easily reach 100 degrees Celsius under load. I wonder how the waterblock for the voltage regulator will affect the X1900 graphics card.
Waterblock for video card voltage regulator and assembly accessories.
These are the main components that are cooled with water. As mentioned above, there are other components that can be cooled this way. For example, Koolance offers a 1200W liquid-cooled power supply. All electronic components of the power supply are immersed in a non-conductive liquid which is pumped through its own external heat sink. This is a special example of alternative liquid cooling, but it does a great job.
Koolance: 1200W liquid-cooled power supply.
Now you can start installing.
Planning and installation
Unlike air cooling systems, installing a liquid cooling system requires some planning. Liquid cooling involves several limitations that the user must take into account.
First, you should always remember convenience during installation. The water tubing must pass freely inside the case and between the components. In addition, the cooling system should leave free space so that further work with it and its components would not cause difficulties.
Secondly, the fluid flow should not be limited by anything. It should also be remembered that the coolant heats up as it passes through each water block. If we designed the system in such a way that water flows into each subsequent water block in the following sequence: first to the processor, then to the chipset, to the video card and, finally, to the voltage regulator of the video card, then the water block of the voltage regulator would always receive water, heated by all previous system components. This scenario is not ideal for the last component.
To somehow alleviate this problem, it would be a good idea to run the coolant along separate, parallel paths. If done correctly, the water flow will be less loaded, and water will flow into the water blocks of each component, without being heated by other components.
The Koolance EXOS-2 kit we have selected for this article is designed primarily to work with 3/8 "tubing, and the CPU waterblock is designed with 3/8" compression connectors. However, the cooling heads of the Koolance chipset and graphics card are designed to work with smaller 1/4 "tubing. This forces the user to use a splitter that splits a 3/8" pipe into two 1/4 "pipes. This circuit works well when we split the stream into two parallel paths. One of these 1/4 "tubes will cool the motherboard chipset, and the other will cool the video card. After the water has taken the heat away from these components, the two 1/4 "tubes will reconnect into one 3/8", through which heated water will flow from the PC case back to the radiator for cooling.
The whole process is presented in the following diagram.
Planned configuration of the cooling system.
When planning the location of your own water cooling system, we recommend that you draw a simple diagram. This will help you install the system correctly. With the plan outlined on paper, you can begin the actual assembly and installation.
To begin with, you can lay out all the parts of the system on the table and estimate the required length of the tubes. Don't cut too short, leave some margin; then you can always cut off the excess.
After the preparatory work, you can start installing the water blocks. The Koolance CPU cooling head we are using requires a metal retention bracket to be installed on the back of the motherboard behind the processor. And best of all, this mounting bracket comes with a plastic spacer to prevent short circuiting with the motherboard. First, we took the motherboard out of the case and installed the mounting bracket.
Then you can remove the heatsink that is attached to the north bridge of the motherboard. We used a Biostar 965PT motherboard, in which the chipset is cooled using a passive heatsink attached with plastic clips.
Motherboard chipset without heatsink. Ready to install a water block.
After removing the chipset heatsink, attach the chipset waterblock fasteners.
During installation, we noticed that the mounting elements of the water block for the chipset, in particular the plastic spacer, are pressing against the resistor on the back of the motherboard. This should be closely monitored during installation. Overtightening the bolts can cause irreparable damage to the motherboard, so be careful and careful!
After installing the fastening elements for the CPU and chipset cooling heads, you can return the motherboard to the PC case and think about connecting the water blocks to the processor and chipset. Remember to remove any old thermal paste from the processor and chipset before applying a new thin layer.
Processor with mounting elements for the water block.
You might want to connect the water pipes to the water blocks before you install them on the motherboard. But be careful when doing this: you may not calculate the pressure and force that will apply to the fragile chipset and processor when bending the tubes. The main thing is to leave a sufficient length of the tubes, because you can cut them to size later.
Now you can carefully install the water blocks on the processor and chipset using the provided mounting hardware. Remember, you don’t have to press them hard; you just need to fit them well on the processor and chipset. Using force can damage components.
After installing waterblocks on the processor and chipset, you can turn your attention to the video card. We remove the radiator present on it and replace it with a water block. In our case, we also removed the voltage regulator heatsink and installed a second water block on the card. After the water blocks are installed on the video card, you can connect the tubes. After that, the video card can be inserted into the PCI Express slot.
After installing all water blocks, connect the remaining pipes. The latter needs to be connected to the tube that leads to the external water cooling unit. Make sure the direction of water movement is correct: the cooled liquid must first enter the water block of the processor.
The moment has come when you can pour water into the tank. Only fill the reservoir to the level indicated in the manufacturer's instructions. As the tank fills up, water will slowly flow into the tubes. Pay particular attention to all attachments and have a towel handy in case of unexpected fluid leaks. At the slightest sign of leakage, fix the problem immediately.
When all components are assembled together, coolant can be added.
If you did everything carefully and there were no leaks in the system, then you need to pump the coolant to remove air bubbles. In the case of the Koolance EXOS-2, this is achieved by closing the contacts on the ATX power supply to supply power to the water pump, but not to power the motherboard.
Let the system work in this mode, while you slowly and carefully tilt the computer to one side and the other so that air bubbles come out of the water blocks. When all the bubbles are gone, you will most likely find that coolant needs to be added to the system. This is normal. Approximately 10 minutes after priming, no air bubbles should be visible in the tubes. If you are convinced that there are no more air bubbles and the likelihood of leakage is excluded, then you can start the system for real.
Test configuration and tests
All the worries about assembly and installation are over. Now is the time to see what the benefits of a water cooling system are.
| Hardware | |
| CPU | Intel Core 2 Duo e4300, 1.8 GHz (overclocked to 2250 MHz), 2 MB L2 cache |
| Platform | Biostar T-Force 965PT (Socket 775), Intel 965 chipset, BIOS vP96CA103BS |
| RAM | Patriot Signature Line, 1x 1024 MB PC2-6400 (CL5-5-5-16) |
| HDD | Western Digital WD1200JB, 120 GB, 7,200 RPM, 8 MB Cache, UltraATA / 100 |
| Net | Integrated Ethernet 1 Gbps |
| Video card | ATI X1900 XTX (PCIe) 512 MB GDDR3 |
| Power Supply | Koolance 1200 W |
| System Software and Drivers | |
| OS | Microsoft Windows XP Professional 5.10.2600, Service Pack 2 |
| DirectX version | 9.0c (4.09.0000.0904) |
| Graphics driver | ATI Catalyst 7.2 |
In our test configuration, we used the Core 2 Duo platform because the E4300 is very easy to overclock. Overclocking allowed us to see how high the temperature would rise and how the standard air cooling system and our new water cooling system would handle it.
The technique is simple: overclock the E4300 processor with standard air cooling as much as possible, and then overclock it with water cooling and compare the results. As it turns out, the E4300 is capable of more. We have increased the processor frequency from the declared 1800 MHz to 2250 MHz. At the same time, the E4300 processor easily coped with the added 450 MHz without increasing the voltage or any other problems. However, the standard cooler did not cope with the work, as the processor temperature rose to an undesirable 62 degrees Celsius under load. Although the core could be overclocked further, further temperature increases could become dangerous, so we stopped, recorded the result and installed a water cooling system.
Before looking at the CPU temperature under load, let's take a look at the system idle temperature.
In idle mode, the water cooling gives a decent drop in CPU temperature, by about 10 degrees. However, this is not such a great achievement, considering that the processor's own cooler belongs to the low-end class, and a high-quality air cooler could be more efficient. However, it is worth remembering that water cooling cannot reduce the temperature so that it is lower than the ambient temperature, which in our case was about 22 degrees Celsius.
When the system is under load - a ten-minute Orthos stress test run - the water cooling unit really showed what it was capable of.
Now this is actually interesting. The stock air cooler cannot even keep the CPU temperature below the undesirably high 60 degrees, and the water cooling system lowered the temperature to 49 degrees at the lowest fan speed. In addition to lowering the temperature, the water cooling system is much quieter than the standard processor cooler.
With the maximum fan speed in the water cooling system, the CPU temperature drops below 40 degrees! This is 24 degrees lower than with a standard cooler under load, and almost as much as its own cooler produces when idle. The result is impressive, although at high fan speeds the water cooling system produces more noise than desired. However, the fan speed is regulated on a 10-point scale, and it is unlikely that in everyday use you will have to set it to full capacity. Orthos puts more stress on the processor than the other benchmarks, and we were very interested to see what the water cooling system is capable of.
In conclusion, pay attention to the results obtained for the video card. Usually the X1900 XTX heats up very much, but we had one of the best air coolers at our disposal - Thermalright HR-03. Let's see what advantages the water cooling has in comparison with this cooler after 10 minutes of the Atitool stress test in the artifact testing mode.
The temperature maintained by the stock cooler is terrible: 89 degrees on the GPU and over 100 degrees on the voltage regulator! The Thermalright HR-03 cooler worked amazingly, cooling the GPU down to 65 degrees, but the temperature of the voltage regulators is still too high - 97 degrees!
The water cooling system lowered the GPU temperature to 59 degrees. This is 30 degrees better than with the stock cooler, and only 6 degrees better than with the HR-03, which further emphasizes its effectiveness.
The separate water block for the voltage regulator is excellent. The HR-03 has no means to cool the voltage regulator, and the water block has dropped the temperature to 77 degrees, which is 25 degrees better than with the stock cooler. This is a very good result.
Conclusion
The results obtained when testing using a water cooling system are pretty obvious: liquid cooling is much more efficient than air cooling.
Water cooling is now available not only to a limited circle of professionals, but also to ordinary users. In addition, modern water cooling systems such as the EXOS-2 are very easy to install and operate on a "plug and play" basis, unlike older systems that required assembly. In addition, modern water cooling kits with illuminated and stylized cases look very cute.
If you are an enthusiast and have tried all air cooling systems, then liquid cooling will be the next logical step for you. Of course there is a risk and water cooling equipment will cost more than air cooling equipment, but the benefits are clear.
Editor's opinion
For a long time, I avoided water cooling because I feared it would be more problematic than helpful. But now I can say with confidence that my opinion has changed: water cooling systems are much easier to install than I thought, and the cooling results speak for themselves. I would also like to express my gratitude to Koolance for providing us with the EXOS-2 set, which was a pleasure to work with.
= ([Hot spot temperature, grC] - [Temperature at the cold point, grC]) / [Dissipated power, W]
This means that if a thermal power of X W is supplied from a hot point to a cold one, and the thermal resistance is Y grC / W, then the temperature difference will be X * Y grC.
Formula for calculating the cooling of a power element
For the case of calculating the heat removal of an electronic power element, the same can be formulated as follows:
[Power element crystal temperature, grC] = [Ambient temperature, grC] + [Dissipated power, W] *
where [ Total thermal resistance, gTs / W] = + [Thermal resistance between the case and the radiator, HRC / W] + (for the case with a radiator),
or [ Total thermal resistance, gTs / W] = [Thermal resistance between crystal and case, ghz / W] + [Thermal resistance between the case and the environment, gTs / W] (for the case without a radiator).
As a result of the calculation, we must obtain such a temperature of the crystal so that it is less than the maximum permissible specified in the reference book.
Where can I get the data for the calculation?
Thermal resistance between die and case for power elements is usually given in the handbook. And it is indicated like this:
Do not be confused by the fact that K / W or K / W units are written in the reference book. This means that this value is given in Kelvin per Watt, in HHZ per W it will be exactly the same, that is, X K / W \u003d X hHZ / W.
Usually, reference books give the maximum possible value of this value, taking into account the technological spread. This is what we need, since we must calculate for the worst case. For example, the maximum possible thermal resistance between the crystal and the case of the power field-effect transistor SPW11N80C3 is 0.8 ghz / W,
Thermal resistance between case and heatsink depends on the type of case. Typical maximum values \u200b\u200bare shown in the table:
| TO-3 | 1.56 |
| TO-3P | 1.00 |
| TO-218 | 1.00 |
| TO-218FP | 3.20 |
| TO-220 | 4.10 |
| TO-225 | 10.00 |
| TO-247 | 1.00 |
| DPACK | 8.33 |
Insulating pad. In our experience, a properly selected and installed insulating pad doubles the thermal resistance.
Thermal resistance between case / radiator and environment... It is quite easy to calculate this thermal resistance with an accuracy acceptable for most devices.
[Thermal resistance, gTs / W] = [120, (HRC * sq. Cm) / W] / [Radiator area or metal part of the element body, sq. cm].
This calculation is suitable for conditions where elements and radiators are installed without creating special conditions for natural (convection) or artificial airflow. The coefficient itself is selected from our practical experience.
Most heat sink specifications contain thermal resistance between the heat sink and the environment. So in the calculation it is necessary to use this value. Calculate this value only if the tabular data for the radiator cannot be found. We often use used radiators to build debug samples, so this formula helps us a lot.
For the case where heat is removed through the PCB contacts, the contact area can also be used in the calculation.
For the case when heat is removed through the leads of an electronic element (typically diodes and zener diodes of relatively low power), the area of \u200b\u200bthe leads is calculated based on the diameter and length of the lead.
[Lead area, sq. cm.] \u003d Pi * ([ Right output length, see] * [Right outlet diameter, cm.] + [Left output length, see] * [Left outlet diameter, cm.])
An example of calculating heat removal from a zener diode without a radiator
Let the zener diode have two leads with a diameter of 1 mm and a length of 1 cm. Let it dissipate 0.5 watts. Then:
The area of \u200b\u200bthe terminals will be about 0.6 sq. cm.
The thermal resistance between the case (pins) and the environment will be 120 / 0.6 \u003d 200.
In this case, the thermal resistance between the crystal and the case (pins) can be neglected, since it is much less than 200.
Let us assume that the maximum temperature at which the device will be operated will be 40 degrees Celsius. Then the crystal temperature \u003d 40 + 200 * 0.5 \u003d 140 ° C, which is acceptable for most zener diodes.
Online calculation of heat sink - radiator
Please note that for plate radiators, the area of \u200b\u200bboth sides of the plate must be considered. For PCB traces used for heat dissipation, only one side needs to be taken, as the other is not in contact with the environment. For needle radiators, it is necessary to roughly estimate the area of \u200b\u200bone needle and multiply this area by the number of needles.
Online calculation of heat removal without a radiator
Several elements on one radiator.
If several elements are installed on one heat sink, then the calculation looks like this. First, we calculate the temperature of the radiator using the formula:
[Radiator temperature, grC] = [Ambient temperature, grC] + [Thermal resistance between the radiator and the environment, gTs / W] * [Total power, W]
[Crystal temperature, grC] = [Radiator temperature, grC] + ([Thermal resistance between the crystal and the case of the element, ghz / W] + [Thermal resistance between the body of the element and the radiator, ghz / W]) * [Power dissipated by an element, W]
North and South bridges are the main components of the motherboard chipset. They are designed to control all computer devices, but if the south bridge got the role of a "little brother" that controls, albeit important, but not fast processes of interaction within and between the board interfaces (disk controllers, network and audio devices, etc.), then the north bridge used as "heavy artillery", as it is responsible for the processor, rAM, video adapter, and also controls all communication processes between these components and the controller In other words, its lot is to control the devices that maximum load while the computer is running.
Location
It is a chip soldered into the motherboard, located on the northern (that is, upper) side and covered with a cooling radiator. Northbridge on most motherboards is cooled by passive heat dissipation, while active cooling using a cooler is the prerogative of powerful systems designed for extreme loads. These can be gaming computers, graphics stations and servers.
Heat sink
A standard heat sink is enough for successful cooling of the north bridge in most cases, including when upgrading the system, but there are often situations in which users overclock their computers by increasing the frequency of the motherboard, processor or video card to increase PC performance. This, in turn, inevitably leads to an increase in the heat release of these components. And given the very close proximity to them and their own increased temperature, the factory cooling of the north bridge in such cases may no longer be enough, which is fraught with very unpleasant consequences, right up to the chip failure. The result of this development of events is likely to be the replacement of the motherboard, since the repair turns out to be economically impractical.
Ready-made cooling systems
In cases of possible overheating, the search for a motherboard cooling system, as a rule, begins with determining the form factor of the computer. There are certain solutions for different board sizes (mini-ATX, micro-ATX or ATX), so when ordering via the Internet (and most often such devices are purchased in this way), it is important to take into account the dimensions of the computer and the dimensions of the installed components.
DIY assembly of the North Bridge cooling system
In retail outlets, the choice of such systems is rather scanty: basically there are cooler-radiator units for cooling processors on sale, so owners of computers that need more efficient heat dissipation most often have to assemble their own designs, showing wonders of ingenuity. Heatsinks from old processors are used, fans are attached to them in various ways, power connectors are re-soldered, and then the resulting hybrid is installed in the bowels of the computer. Moreover, the cooling efficiency is often very high.
If the situation does not allow for one reason or another to purchase a ready-made solution, and you can only rely on your own hands and ingenuity, you should adhere to several important recommendations.
- Measure all distances carefully so that the new system does not overlap the graphics card, RAM, and processor.
- Before installing, remove the video card, RAM and, if necessary, the processor. At the same time, cleaning the cooling systems (and, possibly, replacing the thermal paste) on the processor and video card will not hurt.
- Do not dismantle the "native" cooling radiator of the north bridge unless absolutely necessary. Firstly, it is fraught with the loss of the guarantee (of course, if it is still valid). Secondly, it can be fixed on the chip with a layer of special adhesive thermal paste, which can be cleaned and replaced in a limited space - a very long and difficult process. If the heatsink is attached with special clips, removing it will require access to the back of the motherboard, which is also not always feasible without disassembling the computer.
- In most cases, it is enough to add a suitable cooler, which can be fixed with super glue (with care!) Or with small self-tapping screws screwed into the spaces between the radiator fins. Sometimes the design of the heatsink allows you to use adhesive tape, on which superglue is applied on top, and then a fan is glued (for example, heatsinks for cooling the Gigabyte Northbridge).
- If it is still not possible to solve the problem without a complex replacement, all actions are performed with a motherboard completely free of connected devices. In the case of a clamping fastening, there should be no problems, but you will have to tinker with the adhesive base. You will need a thinner (nail polish remover, gasoline for lighters, or vodka), cotton swabs, and an old plastic card. For installation, you can use the classic KPT-8 (clamp mounting) or hot glue (glue mounting).
- Avoid spilling solvent, thermal paste and glue on other parts of the motherboard.
If everything is done correctly, the temperature readings on any of the tests in different load conditions will be within the normal range, thereby extending the life of the motherboard.
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The engine cooling system is used to maintain normal thermal operation of the engines by intensively removing heat from hot engine parts and transferring this heat to the environment.
The removed heat consists of a part of the heat released in the engine cylinders, which does not turn into work and is not carried away with the exhaust gases, and from the heat of friction work arising from the movement of engine parts.
Most of the heat is removed to the environment by the cooling system, a smaller part by the lubrication system and directly from the outer surfaces of the engine.
Forced heat removal is necessary because at high temperatures of gases in the engine cylinders (during the combustion process 1800–2400 ° C, the average temperature of gases during the operating cycle at full load 600–1000 ° C) the natural heat transfer to the environment is insufficient.
Violation of proper heat dissipation causes deterioration of lubrication of rubbing surfaces, oil burnout and overheating of engine parts. The latter leads to a sharp drop in the strength of the material of the parts and even their burning (for example, exhaust valves). When the engine overheats, the normal clearances between its parts are disrupted, which usually leads to increased wear, seizure and even breakdown. Engine overheating is also harmful because it causes a decrease in the filling ratio, and in gasoline engines, in addition, detonation combustion and self-ignition of the working mixture.
Excessive cooling of the engine is also undesirable, since it entails condensation of fuel particles on the cylinder walls, deterioration of mixture formation and flammability of the working mixture, a decrease in its combustion rate and, as a consequence, a decrease in engine power and economy.
Cooling system classification
In automobile and tractor engines, depending on the working fluid, systems are used liquid and air cooling. The most widely used is liquid cooling.
With liquid cooling, the fluid circulating in the engine cooling system absorbs heat from the cylinder walls and combustion chambers and then transfers this heat using a radiator to the environment.
According to the principle of heat removal to the environment, cooling systems can be closed and open (flowing).
Liquid cooling systems of automotive engines have a closed cooling system, i.e. a constant amount of fluid circulates in the system. In a flow-through cooling system, the heated liquid, after passing through it, is thrown into the environment, and a new one is taken for supply to the engine. The use of such systems is limited to marine and stationary engines.
Air cooling systems are open-loop. The cooling air, after passing through the cooling system, is discharged into the environment.
The classification of cooling systems is shown in Fig. 3.1.
According to the method of circulation of the liquid, the cooling system can be:
compulsory, in which the circulation is provided by a special pump located on the engine (or in the power plant), or the pressure under which the fluid is supplied to the power plant from the external environment;
thermosiphon,in which the circulation of the liquid occurs due to the difference in gravitational forces resulting from the different density of the liquid heated near the surfaces of the engine parts and cooled in the cooler;
combinedin which the hottest parts (cylinder heads, pistons) are forcedly cooled, and the cylinder blocks are cooled according to the thermosiphon principle .
Figure: 3.1. Cooling system classification
Liquid cooling systems can be open or closed.
Open systems - systems communicating with the environment by means of a steam pipe.
Most automobile and tractor engines currently use closed systems cooling systems, i.e. systems separated from the environment by a steam-air valve installed in the radiator plug.
The pressure and, accordingly, the permissible temperature of the coolant (100–105 ° C) in these systems is higher than in open systems (90–95 ° C), as a result of which the difference between the temperatures of the liquid and the air sucked through the radiator and the heat transfer of the radiator increase. This reduces the size of the radiator and the power required to drive the fan and water pump. In closed systems, there is almost no evaporation of water through the steam outlet pipe and its boiling when the engine is running in high altitude conditions.
Liquid cooling system
In fig. 3.2 shows a diagram of a liquid cooling system with forced circulation of the coolant.
Cylinder block cooling jacket 2 and block heads 3, the radiator and pipes are filled with coolant through the filler neck. The liquid washes the walls of the cylinders and combustion chambers of a running engine and, when heated, cools them. Centrifugal pump 1 pumps fluid into the cylinder block jacket, from which the heated fluid enters the block head jacket and then is displaced into the radiator through the upper pipe. The liquid cooled in the radiator returns to the pump through the lower branch pipe.
Figure: 3.2. Liquid cooling system diagram 
The circulation of the liquid, depending on the thermal state of the engine, is changed by a thermostat 4. When the coolant temperature is below 70–75 ° C, the main thermostat valve is closed. In this case, the liquid does not enter the radiator. 5 , and circulates along a small circuit through the branch pipe 6, which contributes to the rapid warming up of the engine to the optimal thermal regime. When the thermostat thermostat is heated to 70–75 ° C, the main thermostat valve starts to open and let water into the radiator, where it is cooled. The thermostat opens completely at 83–90 ° С. From this moment on, the water circulates along the radiator, i.e., large, circuit. The temperature of the engine is also regulated by means of rotary louvers, by changing the air flow created by the fan 7 and passing through the radiator.
In recent years, the most effective and rational way to automatically control the temperature of the engine is to change the performance of the fan itself.
Elements of the fluid system
Thermostatdesigned to provide automatic control of the coolant temperature while the engine is running.
To quickly warm up the engine when it is started, a thermostat is installed in the outlet pipe of the cylinder head jacket. It maintains the desired coolant temperature by varying the rate at which it circulates through the radiator.
In fig. 3.3 shows a bellows-type thermostat. It consists of a body 2, corrugated cylinder (bellows), valve 1 and the stem connecting the bellows to the valve . The bellows is made of thin brass and filled with a highly volatile liquid (for example, ether or a mixture of ethyl alcohol and water). Windows located in the thermostat housing 3 depending on the temperature of the coolant, they can either remain open or be closed valves .
When the temperature of the coolant washing the bellows is below 70 ° C, the valve 1 closed and windows 3 are open. As a result, the coolant does not enter the radiator, but circulates inside the engine jacket. When the coolant temperature rises above 70 ° C, the bellows under the vapor pressure of the liquid evaporating in it lengthens and begins to open the valve 1 and gradually cover the windows with valves 3. When the coolant temperature is above 80-85 ° C, the valve 1 opens completely, the windows close completely, as a result of which all the coolant circulates through the radiator. Currently, this type of thermostat is used very rarely.
Figure: 3.3. Bellows thermostat
Now engines are fitted with thermostats, in which the damper 1 opens with the expansion of the solid filler - ceresin (Fig. 3.4). This substance expands with increasing temperature and opens the damper 1 , ensuring the flow of coolant into the radiator.
Figure: 3.4. Solid fill thermostat 
Radiator is a heat dissipating device designed to transfer the heat of the coolant to the surrounding air.
Radiators of automobile and tractor engines consist of upper and lower reservoirs, interconnected by a large number of thin tubes.
To enhance the transfer of heat from the coolant to the air, the fluid flow in the radiator is directed through a series of narrow tubes or channels blown with air. Radiators are made of materials that conduct well and give off heat (brass and aluminum).
Depending on the design of the cooling grille, radiators are divided into tubular, plate and honeycomb.
Currently, the most widespread are tubular radiators... The cooling grille of such radiators (Fig. 3.5a) consists of vertical tubes of oval or circular cross-section passing through a row of thin horizontal plates and soldered to the upper and lower radiator tanks. The presence of fins improves heat transfer and increases the rigidity of the radiator. Tubes of oval (flat) cross-section are preferable, since with the same cross-section of the jet, their cooling surface is larger than the cooling surface of round tubes; in addition, when the water in the radiator freezes, the flat tubes do not break, but only change the shape of the cross section.
Figure: 3.5. Radiators
AT plate radiators the cooling grill (Fig.3.5b) is designed so that the coolant circulates in space , formed by each pair of plates welded together along the edges. The upper and lower ends of the plates are also soldered into the holes of the upper and lower radiator reservoirs. The air cooling the radiator is sucked in by the fan through the passages between the brazed plates. To increase the cooling surface, the plates are usually wavy. Plate radiators have a larger cooling surface than tubular radiators, but due to a number of disadvantages (rapid contamination, a large number of soldered seams, the need for more careful maintenance), they are used relatively rarely.
Cellular radiator refers to radiators with air pipes (Fig.3.5c). In the grille of a honeycomb radiator, air flows through horizontal, circular tubes that are washed from the outside with water or coolant. To make it possible to weld the ends of the tubes, their edges are expanded so that in cross-section they have the shape of a regular hexagon.
The advantage of cellular radiators is a large cooling surface compared to other types of radiators. Due to a number of disadvantages, most of which are the same as those of plate radiators, honeycomb radiators are extremely rare nowadays.
A steam valve is installed in the radiator filler cap 2 and air valve 1 , which serve to maintain the pressure within the specified limits (Fig. 3.6).
Figure: 3.6. Radiator cap 
Water pump ensures circulation of coolant in the system. As a rule, small-sized single-stage low-pressure centrifugal pumps with a capacity of up to 13 m 3 / h, creating a pressure of 0.05–0.2 MPa, are installed in cooling systems. Such pumps are structurally simple, reliable and provide high performance (Fig. 3.7).
The pump casing and impeller are cast from magnesium, aluminum alloys; the impeller, in addition, is made of plastics. In water pumps for automobile engines, semi-closed impellers are usually used, that is, impellers with one disc.
The impellers of centrifugal water pumps are often mounted on the same roller as the fan. In this case, the pump is installed in the upper front of the engine, it is driven from the crankshaft using a V-belt drive.
Figure: 3.7. Water pump 
The belt drive can also be used when installing the centrifugal pump separately from the fan. In some engines of trucks and tractors, the water pump is driven from the crankshaft by a gear transmission. The shaft of a centrifugal water pump is usually mounted on rolling bearings and equipped with simple or self-adjusting oil seals for sealing the working surface.
Fanin liquid cooling systems, they are installed to create an artificial air flow passing through the radiator. Fans of automobile and tractor engines are divided into two types: a) with blades stamped from sheet steel attached to the hub; b) with blades that are cast in one piece with the hub.
The number of fan blades varies from four to six. Increasing the number of blades above six is \u200b\u200bimpractical, since the fan performance increases very insignificantly. The fan blades can be flat and convex.
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