Case Ventilation. myths and reality
Cooling of different components. one of overclockers’ (and not only overclockers’) favorite topics. Good case ventilation is very important here. because by reducing the temperature in it by at least a couple of degrees we will reduce the temperature of all the elements inside by the same amount. Unfortunately, I have not yet come across a more or less accurate method of calculating the ventilation of an enclosure. But in abundance from article to article there are general recommendations which have become bronzed because of frequent use and cannot be taken at face value.
These are the most common of these myths:
- The performance of the blowing fans should be approximately equal to the performance of the blowing fans
- It is important to let the cool air in from below and let it out from above
- The more expansion slots and 5″ bays in the case, the worse its ventilation is
- Replacing the usual stubs with round ones noticeably improves the ventilation of the case.
- The front fan noticeably lowers temperature in the case.
As a result the struggle for ventilating the case often comes to installation of fans of maximum possible size and productivity in all standard places, after which a drill (hacksaw, jigsaw, chisel, sledgehammer, “angle grinder”, autogenous blowtorch) is taken in hands. underline the necessary :-), and the fans are plugged into the non-standard places. After that for greater effect a pair of fans is added inside the case. Usually for the air-conditioning of the video-card and the hard disk.
About time, effort and money involved it is better not to say. To tell the truth, the result is usually quite good, but the noise, emitted by this “battery” at full speed is beyond any limits, and the dust it sucks with the speed of a vacuum cleaner. As a consequence, soon the case starts to grow with fenbasse and reobasses, becoming similar to a mid-range mixing console. And the process of starting a game instead of just clicking the mouse now looks like getting ready to take off an airliner. you have to remember to turn up the speed of all these fans. In this article I will try to show how you can achieve a similar effect “with little effort.
All mass housing can be divided into three types. the desktop, the Tower with a top (horizontal) power supply and the Tower with a side (vertical) power supply. The last two account for the bulk of the market. Each has advantages and disadvantages, but the third kind is considered the worst in terms of ventilation. here the cpu is in an airtight “” next to the power supply unit and it is rather difficult to arrange fresh air supply there.
The general principles of ventilation are quite simple. Firstly, the fans should not interfere with natural convection (from bottom to top), but help it. Secondly, it is undesirable to have non-blown stagnant areas, especially in places where natural convection is difficult (primarily the lower surfaces of horizontal elements). Thirdly, the greater is the volume of air pumped through the case, the less is the temperature difference in it as compared to the “outside” temperature. Fourthly, the flow does not like different “twists”. changes of direction, contraction-expansion, etc.п.
How does air exchange occur?? Suppose the fan is pumping air into the housing and the pressure rises. The dependence of the flow rate on the pressure is called the operating characteristic of the fan. The higher the pressure, the less air the fan will pump in and the more air will be exhausted through the vents. At some point the amount of air pumped in equals the amount of air leaving the enclosure and the pressure does not increase further. The larger the area of the vents, the lower the pressure will be and the better the ventilation will be. So simply increasing the area of these “no noise and dust” holes can sometimes achieve more than installing additional fans. What will change if the fan doesn’t blow air in, but blows it out?? Only the direction of flow will change, the flow rate will remain the same.
The “classic” ways of ventilating a case with a top mounted PSU are shown in Fig.1-3. Actually, it’s actually three variations of the same way, where the air goes diagonally around the case (from the front bottom corner to the back top corner). Red indicates non-blown areas. The flow resistance has nothing to do with how tightly they are filled. it goes past them all the same. Pay attention to the lower area where the video card is located. One of the most critical to overheating computer components. Installation of the front fan allows to bring some fresh air to it (and to the south bridge as well), knocking down the temperature by a couple of degrees. But in this case the hard disk is “on the side of life” (if it is installed into standard place). In Fig.4 shows why this is the case. Here is a schematic representation of air flows through the fan (darker color corresponds to higher speed). On the intake side, the air enters evenly on all sides, with its velocity dropping rapidly as it moves away from the fan. On the discharge side the “range” of the air flow is noticeably greater, but only along the axis. There’s an unbreathable area on the side of the fan. The same “aerodynamic shadow” appears behind the fan hub, but it quickly goes away.
I will use an example from life to illustrate this point. To find the best way to cool my desktop I turned the fan in the PSU upside down. In theory, this should improve the PSU cooling. because now it is blown with fresh air and not with used air from the case. However, the thermo-sensor of the PSU indicated just the opposite. The temperature has increased by two degrees! How This Could Happen? The answer is simple. the card with the sensor is installed away from the fan and is therefore in the aerodynamic shadow. Since together with the temperature sensor in this shade there were some other elements, the status quo was restored in order to avoid their failure.
Let’s move on from theory to practice. Our main task. to increase the area of ventilation holes, preferably quickly and without using any plumbing tools. Their area should be at least equal to the fan effective area (that is the area swept by the blades), and better to exceed it one and a half times. For example, for an 80mm fan, the effective area is approximately 33 sq.ft.see. If there are several fans and they are all blowing (or vice versa), their effective area is added up. This is especially true for cases of old designs, which still remember the Pentium-2 and yet are still being produced (and sold) until the dies are completely worn out.
My Codegen desktop is one of those “veterans”, having survived three motherboards already. As for “comfort” it has a place for a 90mm front fan, which according to the designers’ idea should draw air through a slot at the bottom of the front panel with only 5 sq.m. of area. see., and symbolical holes 1,5 mm in diameter in front of it (later I’ve reamed them up to 4 mm in a staggered manner). it looks even more beautiful). Of course, the case is not a submarine, the air will be sucked in through other small cracks and leaks, the exact accounting of which is impossible. But anyway the ventilation in normal mode reminds of running in gas mask.
Computer configuration during testing:
- CPU Athlon T-red-B 1,6v. 1800@166X11 with an Evercool ND15-715 cooler connected via a 3-post. switch (used second speed, 2700 rpm)
- M/b Epox 8RDA3, the bridge cooling is off
- video Asus 8440 Deluxe (GF4ti4400), act. the cooler covers the chip and memory.
- 512 Mb RAM Hynix
- HDD Samsung 7200 RPM
- CD-ROM, FDD, Rack-container
- TV/capture card Flyvideo
- Codegen 250w power supply
- Total power (without PSU). about 180 W
Processor temperature was measured with Sandra, graphics card. by the built-in sensors via SmartDoctor, in the case under the top lid above the processor (did not forget. desktop case) was placed remote sensor of electronic thermometer, the second sensor of this thermometer measured the temperature in the room. Then the results were brought to external temperature of 23 degrees.
The system was stressed by running in a cycle of 3DMark2001SE game tests. At baseline, the temperature in the case was 15 degrees higher than the outside temperature, the video card (chip/memory) was 55/38 deg., Processor at 39 deg. For comparison we measured with the lid open. The results: the video card temperature is higher than the external temperature of 44/30 degrees, the processor. at 26 degrees.
First let’s try to go the traditional way. What is the first thought that comes to mind when you look at this case? “If there’s a hole for a fan, there should be something there” (quite according to “Golden Calf”). Well, let’s do it. What’s the result? The case temperature sensor did not respond to our manipulations at all, the processor temperature went down by 1 degree, and the video card by 4-5 degrees (by the way, another traditional move gave approximately the same result). installing Gembird SB-A blocker next to the video card). Actually, this is where the “traditional way” ends.
Now let’s return everything to its original state and go another way. Let’s take out the two plugs of the expansion slots next to the video card. This helps to kill two birds with one stone: it opens a new hole for case ventilation and eliminates dead space near the video card. and in addition let’s break a protective “comb” at front air’s intake (thanks it’s from below and it’s not visible anyway). it will triple in area and the total size of the vents will be 45 sq. cm. cm.
The result is immediate. the case temperature dropped by two degrees, and the video card pleased me even more, dropping at once 9 degrees on the chip and 7 degrees on the memory. You should agree that this is not a bad result and it is absolutely free. This variant can be recommended for cards with passive cooler as an alternative to installing a fan. And if that’s not enough? Adding a front fan on the intake side produces a paradoxical result. the temperature of both the case and the graphics card. it goes up! Not much, only one degree, but still. The explanation is simple. now more air enters the case through the front opening and less. through the back past the graphics card.
And if you put it on the blowout? That’s another matter. Both fans (in PSU and additional one) are now switched in parallel, their costs are added up, and here is the result. the graphics card “cooled down” another 3-4 degrees, and the total drop in temperature compared to the initial variant was 12 degrees for the video chip, 10 degrees for video memory and 5 degrees in the case (and therefore the processor). Notice that the video card is cooler here than in the open case! Our expenses were limited by buying one middle-power case fan.
Finally, the last option, the “extreme” one. all three fans (PSU, front and blower) are blowing out, additionally one more slot is opened at the back. The blower was installed in the lower (of the two) five-inch compartment instead of the removed Rack-container. Results. the processor “cooled down” compared to the previous version by 4 degrees (and now it’s the same 4 degrees hotter than itself in the open case), and the video card lost another couple of degrees. True, the case temperature gauge didn’t show any drop. cold air goes below it because additional fans do not take air from the top but from the middle of the case. The overall results are summarized in the table. This shows the absolute temperature of the components at 23 degrees Celsius in the room.
|Open. vent slots.blowing||57||49||65|
|Open. ventilation slots.and blower||53||48||63|
Now that we have understood and tested the general principles of effective ventilation in practice, let us apply them to the most common case. Towers with an overhead PSU.
In Fig.6 shows the most efficient way to cool such an enclosure. The additional fan on the back wall actually provides the same purge mode as in my last experiment. Since almost half of the heat is generated by the processor, it makes sense to feed some of the cool air directly into the processor’s operating area. This is done through a free three-inch or five-inch compartment on the front wall. both its plugs (plastic and metal) are to be removed and the way to decorate the formed hole. a matter of skill and imagination. In the simplest case you can buy a panel with a couple of small fans (take them off at once, they are useless), luckily there are many varieties of such “gimmicks” for 5″ slots. from the usual grid to the panels with built-in electronic indicator, USB ports or fanbases (although they have a smaller grid area).
Rack-container installation also provides quite good ventilation. Keep in mind that all these units must be installed in the lowest bay. The choice of a particular variant depends on what you need to “freeze” first. If the processor or memory gets overheated, the holes should be bigger, and if the video card. it is possible to do without them but open more slots at the bottom. The total area of the holes should be at least 70-80 sq. see. depending on the size of the fans. For reference: the area of one slot hole is 13 sq. cm., open three-inch compartment. 30 sq. see., five-inch. 15-30 kv. cm². with the aforementioned decorative grille and 60 sq. ft. see for fully open. Another 10-15 sq. see. removing the blanking plugs from the port holes on the back. Oh yes, I almost forgot, there is also a standard air intake at the bottom of the front panel of 5-30 kv. see., and some cases also have holes in the side walls.
If there’s a fan hole on the top panel, it’s a shame not to use it. Put something in there that’s not too powerful to blow out. If there is no such hole, you don’t need to cut it out. It is better to buy a special blower and install it to the top 5″ compartment. This will be especially useful for those who for some reason do not have a hole for an extra fan under the PSU, or it is used for direct CPU cooling. But in this variant it is worth making a duct to direct fresh air from the lower five or three-inch compartment to the processor area. Without it, a lot of that heat can go straight into the blower, not picking up enough heat on the way.
Pictured. 8 here is a rather exotic layout with a bottom fan blowing out. This is worse than the previous two and should only be used as a last resort when you want to cool the graphics card first. In fact, this scheme provides two independent streams. the first (lower, from the back wall to the front) cools the graphics card, expansion cards and the South Bridge, and the second (from the front wall to the back) cools the top half of the case. Advantages of the circuit. the combined blowing capacity of the fans increases, a lot of hot air from the graphics card is promptly blown outside and the overall flow resistance in the case is lower.
But there are also considerable disadvantages. The main one is that for the sake of design, the lower holes in the front wall, through which the air is blown out, usually have a much smaller area than the effective area of the front fan. In addition, the airflow has to change direction twice, which it doesn’t like. The result is the same “running in a gas mask”. for example, if the hole in the case is half the size of the fan, the fan capacity drops approximately by half, and that does not take into account the back pressure in the case. Conversely, the noise, on the other hand, will be greater. Seeping through narrow slots, small holes, intricate “squiggles” and other design tricks in the front panel, the air flow can make not at all artistic whistling. Also, the noise from the front fan (unlike the rear fan) is not shielded by the case.
you can increase the efficiency of the front fan by introducing additional air into the cavity between the front panel and the metal front wall of the case. For that we can do it the old-fashioned way. let’s take out the plastic (this time only the plastic!) The plug of the bottom three-inch compartment. But we still need to blow cool air into the upper half of the case also from the front. These flows need to be separated by a baffle under the bottom five-inch compartment.
Now let’s look at the flow in the enclosure. In the first and second scheme, the main flow moves from the bottom upwards. The flow resistance is determined by the bottleneck in its path. In this case it is a slot at the graphics card level: the graphics card takes up about half of the case and on the other side is the hard drive with the cable protruding. Since you can not move the video card to another place, you just move the hard drive. You can put it down or put it in one of the 5″ bays (better in the one used as an air intake). In both cases, the hard drive will be perfectly ventilated, which is good for its health. However, the bottleneck in the flow path is not really here, but at the entrance to the case. Its speed is much higher there and aerodynamic losses are proportional to the square of the speed. So “sticking” and stacking loops in terms of air exchange does almost nothing.
I hear, I hear snide voices. but what about the fearful stories about dust, which you install fans on airflow will be sucked out through CD-ROM and FDD? Answering. The air follows the path of least resistance and with good ventilation will not go into narrow slots when there are large windows nearby. Besides the standard ventilation system works on a blow-out, in branded cases and notebooks too (and there are not fools sitting there, as some colleagues like to say, when other arguments run out 🙂
A word or two about tauers with lateral PSUs. Despite the large number of openings located in the most unexpected places, the ventilation of these cases is disgusting. If the traditional way (by opening the neighboring slots) can improve the air circulation of the video card, then with the processor have to play with. For good blowing its “” you need to somehow remove the hot air from there. The most effective. Cut in the top panel of the blowing fan, but this is very laborious. So let’s try some alternative methods. InWin cases on the top of the rear wall there are ventilation holes of unknown purpose. The warm air will not escape from there, t.к. there is a vacuum in the case from the PSU fan, and the supply of cold air under the ceiling is ineffective. To keep them from going to waste, put a blower there to blow out. In those cases which don’t have it either, you can direct the blower forward and connect it to an empty five-inch compartment with a duct (of course if you remove both plugs from it. fig.9).
Another option. installation of a PSU with a powerful fan in which the air intake is only on the “” side. PSUs with a 120mm fan on the side of the case are available for sale. in theory, it should be enough for good ventilation. You can do it the other way around. to give with a fan or a blower through the air duct in this area fresh air with the expectation that the jet will “reach” the unbreathable corners. In general, the field for experimentation with these cases is really vast.
There are still a few myths about fan selection. but it is worth to dedicate a separate article to this question.
- Let’s start with the back panel. The PSU cooler at the back operates to blow air out
- Let’s go to the front panel. you have to install the component for blowing air
- The next part is the side panel
- The last part is the top panel.
The minimum required number of fans in a Tower case is two, of course it is better to install one “Carlson” on the front panel for cooling, and another for blowing.
How you can install fans in a computer case
Installation of coolers in the system unit is made by different schemes. Before you start it is necessary to get acquainted with them, because the wrong location of these units can cause even more damage than their absence. Usually the motherboard has a pair of connectors for cooling. They can be engaged both or only one. The fan installation diagrams in the computer case then will be as follows:
You can choose any of these options, but the last one is the most preferable. Note that using only one cooler in some way or another disturbs the air balance in a closed system. So let’s look at each option separately.
A rear-mounted fan must be able to blow hot air outward. In this case, the warm air flow is no longer going through the power supply and does not cause it to overheat. In addition, the cooling of the processor is improved. This has the disadvantage that it creates a vacuum in the case and the intake of air through the various openings in the case brings with it a lot of dust. However, using this arrangement still improves the situation significantly.
Correct installation of coolers in the system unit
Once the coolers are selected and purchased you can begin to install them in the system unit. For a proper installation, it is important to understand how the air moves inside the computer and how the coolers will affect it. The convection causes the hot air to rise to the top of the case itself, and to cool most efficiently, the coolers must be mounted so as to take advantage of and amplify this natural air movement, rather than to oppose it.
That is why coolers are traditionally installed on top of the case to blow the heated air out of the case. And in the lower part of the case the fans should be on the blow side, because it enhances natural air flow from bottom to top. The picture below shows the possible locations for mounting the coolers and the direction in which they should blow the air. This scheme of installing coolers in the system unit is considered the most correct.
If you ignore the natural air movement and, for example, in the upper part of the system to install a cooler for blowing, it can even increase the temperature of computer components. Hard disks in particular will be badly affected if a stream of hot air from the CPU heatsink is directed to them.
The process of installing the cooler into the system unit is not difficult. The cooler is installed on the inside of the system unit and then fixed with 4 screws on the outside. When installing it is important to make sure that the cooler directs the air in the proper direction. To do this, the cooler usually has an arrow that indicates where the air will move.
After installing the cooler, it must be connected to the motherboard (if using a 3 or 4 pin connector) or to the computer power supply unit (if using a connector MOLEX).
Of course all the actions should be performed with the computer turned off and de-energized. Otherwise there is a risk to damage components or get an electric shock.
Users, who are building their computer for the first time, often have a question about how to properly install the case coolers in the system unit for the cooling to work as efficiently as possible. Actually there is nothing complicated about it, you just need to choose a suitable cooler and install it so that it does not interfere with the natural air flow.
Many people have a question about how to determine whether the fan is blowing or blowing out? It is quite simple, the direction of the blades helps to do it. If the machine is blow-out, the blades are raked downwards. The movement is counterclockwise.
If the device is blowing, the blades are raked downwards. The movement is counterclockwise. Today’s computer cooling unit housings have arrows that represent the rotation and direction of airflow. Any unit has two arrows.
Additional test, simplified scheme: one fan blowing out (closed front panel)
Next I propose to find out how necessary it is to have two fans to blow hot air out. To do this, of course, I remove the fan that is over the CPU cooler.
This action makes the results a bit worse comparing to the scheme with two fans for blowing air. Processor temperature went up 1 degree, and the graphics card also went up 1 degree. Fan speeds have increased.
Please see the attachment for more detailed results.
Correct fan positioning is very important. Decide which side your fan should be facing in order to effectively ventilate your computer case components. If the wrong side of the fan, you can completely lose ventilation.
Inside a closed system unit, air moves from the front to the bottom, up to the back. Any fan inside the computer must amplify this movement. In this way, cool air enters the unit more intensively and hot air is blown out of the enclosure more quickly.
To minimize errors that occur when installing the fan, some manufacturers indicate which side of the fan. This is usually indicated by arrows showing the direction of airflow generated.
How to mount the fan in different parts of the case
Before mounting the fan, you must examine all possible installation locations. The cooling unit may be placed on the back of the chassis if there is no other location. In this case the purpose of installation is to ventilate the power supply. Consequently, the cooler should be installed next to it and the air should be directed outward.
If the computer has a suitable installation place directly on the front panel, it is better to put the fan there. Make sure that it provides air flow inside. Fresh air will rush in and cool your PC componentry.
If the computer has space for possible installation in both the front and the back, you can create a very efficient ventilation system. In addition to excellent cooling, this option has several other advantages. The air draft created will prevent dust from settling and stabilize the pressure inside the case to reduce noise.
If the wrong side of the fan is installed
Placing a “backward” fan in the back will interfere with the intended airflow. It interferes with the movement of cold air from below into the housing. This means that the expected cooling will not happen.
If the fan is installed in the front and is oriented to “blow”, it will block the air that was supposed to get in through the front panel grill. It will also cause overheating of components. Undoubtedly, the pressure inside the case will drop and dust will settle on the internal parts. Settled dust will cause additional heat to build up in the cells.
Other installation errors
If you incorrectly place 2 fans, one on the back to blow in and one on the front to blow out, you will get a closed loop of heated air inside your computer case. This will drastically interfere with ventilation and cause severe overheating of the components.
In the wrong case, when both units are operating on “blowing”, there will be increased pressure inside the computer. It will create increased load on the fans and will not provide the necessary cooling of PC components.
If both fans are on “blow”, the heated internal air ceases to circulate properly. The heat transfer will stop, the dust can settle inside. At the same time, the internal pressure would drop. This will have a negative impact on the temperature of all internal elements.
A guide to unlocking and fine-tuning the air-cooling potential of personal computers
Unfortunately a simple and universal recipe, where and how to screw fans does not exist, aerodynamic processes inside the case are quite complex, also vary greatly depending on the configuration and so just on the knee do not calculate them. The information below can be useful not only for optimizing cooling in your finished computer, but also when selecting a new case.
п.1 I will begin by comparing the two basic blowdown schemes. with predominance of blowing fans and blowing fans. There are no major differences between them, both are able to pump air confidently through the enclosure. However, the scheme on the blowing fans (the so-called negative pressure) will make it a little more efficient, due to a more laminar (calm) movement of air masses. Blowers in turn create eddies that inhibit and agitate the air flow and have a negative effect on performance. On the other hand, these whirls more effectively remove heat from passive radiators and other heating elements, which do not have their own fans. Thus it improves cooling of chipset, RAM, NVMe storages.
п.2. Setting nuances aside, negative pressure is in my opinion preferable, but that is not a reason to refuse blower fans. Working at up to 20% less RPM than blowing fans will add practically no noise, while noticeably helping to pull the air through the case by pushing it from behind. Or scientifically speaking. Reduce the aerodynamic drag of the enclosure system.
п.3 Contrary to popular belief, there are no clearly defined airflows in the enclosure, the operation of any fans inside will primarily produce areas of low and high pressure. The movement of air is caused by its tendency to fill low pressure areas (as well as leave high pressure areas), and it does this by the path of least resistance. The resistance in its turn is determined by the influence of neighboring high and low pressure areas, as well as by the distance to the ventilation holes and their area. Let’s consider these processes in detail on the example of a standard dual-fan video card:
As you can see, along with the fresh air outside the case, the rarefaction under the graphics card will willingly fill its own heated exhaust. In the absence of other fans, only a small force of convection, pulling the warm air upwards, can prevent this. To improve the situation case fans are to. Either blowing on the front side, which will reduce draft resistance along that direction, or blowing out the top, preventing exhaust air from being drawn back in:
In this case, another problem arises. Excessive air circulation in the enclosure causes parasitic drafts (pink in the figure), which prevent the fans from carrying out their useful work, thus reducing their efficiency. It can be reduced by balancing the inflow and exhaust (which is not easily possible in every building), or eliminated by carefully sealing all unnecessary openings.
п.4 Special attention should be paid to the influence of nearby fans on each other, because this influence can often have a negative effect on their performance. As an exaggerated example, imagine two identical fans sandwiched in opposite directions. They will spin and make noise, but do zero work moving air. Naturally, such situations do not occur in real-world scenarios, but a partial manifestation is quite common. Below is such an example:
Similar phenomena can be observed with intake if one fan is installed on the front panel and the other on the bottom. And also with the PSU fan up and the graphics card in the lower slots, with an inevitable rise in temperature of both components. If the fans are oriented perpendicularly, the losses are not so critical, but it must be taken into account that, firstly, the resulting performance will be lower than the air volume, which both can pump separately. Secondly, it is desirable to tune them to the same capacity, otherwise the weaker fan will risk to be a vent for the other one by blowing air in the opposite direction that will negate the sense of its use.
п.5 The basic task that the ventilation of an enclosure comes down to. provide the cooling systems of each computer node with cold air in the volume equal to their flow (this is how much the video card and processor pump through themselves). Although it often makes sense to make a compromise and let the cooler partially use the air blown by the graphics card. Further increasing the power of the hood is almost useless. Two conditions are important to keep noise to a minimum in this process. Make each fan about the same level of noise and give them the highest possible efficiency. And all this relying solely on the power of your imagination, simulating in your head the movement of air masses under the influence of the factors listed in the article. Not the easiest task, but hopefully many readers will find it fascinating.
п.6 Additions and notes:
1) The more resistance the enclosure puts up, the more important is the sealing of the parasitic flow and the more important is the pressure created by the fans (regardless of their orientation). Factors Increasing Resistance. a blank front panel and bottom, an array of baskets for hard drives in the front, a clutter of cables. The friction of the air against the walls of the enclosure also creates resistance, so in wide enclosures, the air moves a little easier.
2) When using more blowing fans, the first thing to do is to seal the roof and back wall cavities. The opposite is true with superchargers.
3) Graphics cards of non-reference design with traditional fans produce a vertical airflow, so if you are keen on blowing fans in the upper half of the case they can conflict with the graphics card’s CO.
Custom PC Build: How to setup your desktop cooling fans for proper air flow
4) The weaker the CO of the graphics card, the more heat will be dissipated passively from the back side of the board. And here the vortices from the blowing fans can help, but taking into account the previous point, it works only with reference turbines.
5) Pulling air through a motherboard pin panel, when negative pressure is completely impossible to eliminate, but modern motherboards have a fan guard installed at this point, which directs air through the VRM heatsink, helping to cool it.
6) Enclosures with a single exhaust fan on the back wall. is not a death sentence for hot systems, because its efficiency can be easily raised up to nearly 100%. In contrast, cases with a top-mounted PSU. real evil. If you put a modern unit in there that is cooled by a low-speed fan, depending on the speed of the rear one, the air draft through the PSU risks getting close to zero, which can lead to all sorts of unpleasant consequences.