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A Guide on how to fix Heat Problems


What is heat, and what causes it?
Heat is displaced energy. Any action that causes a change to an electrical flow, will generate heat. The amount of work done, the devices designs, and the energy they waste are what determines the amount of heat that is generated. We deal with this heat from each device by ether brushing it with air or sinking it away with a cooler, then moving it out of the case into the air circulation of the room. The configuration and design of each cooler and fan, and the part it plays in the overall cooling system, determines there heat handling capacity. The different parts of the cooling system, along with the case cooling configuration (as a whole), can only dissipate so much heat. Anything beyond that point, the protected device will overheat. Going beyond the devices recommended thermal (heat) limit cost you every time you do it; you pay with a shorter device life span, operating system errors, and device failures.

Why customize a computer:
No one comes to me because I can build a computer cheaper than DELL, because I can’t. You don’t want a cookie cutter or a me-too computer (a Retail Store Computer). You may want something that is on the leading edge of technology. You may want something that’s higher quality, balanced, longer lasting, better running, and engineered to your needs. One of the most useful things that we builders can bring to the table is a well engineered cooling system. We can even design a cooling system to circumvent an unfavorable or bad environment.


A Short Book about cooling:
The best I can do without writing a book about this subject is to point you in the right direction. There are ways of getting great cooling performance at reasonable decibel levels. One of the best reasons for building a custom built computer is having the opportunity of designing a well-engineered cooling system. With it, the computer will last longer and run better. Be mindful of where you place the computer. Computers like cool air conditioned rooms with a good circulation of filtered air, but most will never see this ideal environment. The goal is to design the cooling system to where the computer will easily survive the worst conditions that it will ever be exposed to. Below is a list of helpful things to keep in mind during the design and placement decisions.

  1. A number of fans are bought in the needed sizes at their own specific volumes of air, to fit in the chosen case.
  2. Some fans push air out of the case, others pull air in.
  3. Bigger fans move more air while making less noise at a similar RPM and at a lower amperage. (Read more about this below)
  4. You can configure the fans to create suction or compression in the case so that open case vents and holes can act like another fan. Suction should normally be avoided because it fights the flow of the power supply's cooling fan. This can cause the power supply to overheat as its hot air is sucked into the case (not a good idea).
  5. Use filters where possible and clean them often.
  6. The hot components are: (hottest listed first) the CPU, the video card, the north bridge, the hard drive, the memory, and the power supply. Make sure each ones cooling needs are addressed.
  7. Sectioning off different air flow systems or cooling sections is another good strategy.
  8. If you need the maximum out-putt from a fan, plug it directly into a power supply connector. Depending on the connected hardware, If you plug it into a fan controller or the mother board, the fan may loose from 0% to 30% of its performance capability.
  9. One good strategy for a high heat area in the case (like the CPU and GPUs) is; fresh cool air blowing directly at that area, then a fan close by, expelling that hot air out of the case.
  10. Install the fans so that the airflow is not fighting its self, so it carefully flows through the computer and keeps each part at the desired temperature
  11. Cables should be cleanly routed and secured so that they do not block or influence the air flow. Otherwise, there influence should be designed into the cooling plan.
  12. Large thick fans have powerful motors and big blades, when throttled back to a lesser speed, they still move a lot of air at lower RPMs
  13. Quiet fans exit air from the case. If you have any noisy fans, they belong inside the case blowing air into a cooler. This makes for a quieter computer.
  14. Cooling a hard drive does not require fast air flow. Fresh air only needs to flow near it so that it does not set there and cook in its own heat.
  15. If your main board has a north bridge, install a fan or extra cooling if it is getting hot. More and fast memory can stress the memory controller and eventually kill the north bridge's video path
  16. If you have any fans that you monitor the RPMs on, take a reading before and after the side is removed from your case. This will tell you about the load that each of those fans face. This does not work on internal fans.
  17. The amp rating is a good indication of a fan's ability to resist opposition (how weak the fan is).
  18. Engineering the airflow outside the case is important too. Mind where the hot exhaust goes to, and the in-take air comes from. You do not want to recirculate hot air or create a heat loop..

  1. The coldest and dirtiest air in a room is on the floor. Hot air rises, cold air falls.
  2. Fast temperature changes cause condensation, condensation causes rust and electrical problems. For this reason, you should keep the computer away from windows, doors, sky lights, vents, heaters, and air conditioners. The temperature varies quickly in those places. As the sun goes behind the cloud, the temperature around the window drops more than 10° in a few seconds, and then the sun comes back out. This happens time after time for several hours every day.
  3. One good strategy for high heat areas in a room; like windows, sky lights, stoves, ovens, and heaters, is to keep your computer away from them. The warmest air in the room is radiating from these items.
  4. Never put a computer in a confined space, The computer's intake fans and vents need a fresh supply of cool air circulating around them. Examples of a confined space- under a desk, a hot closed room, in a cabinet or closet.
  5. If you have functional vents under your computer, the computer needs to be placed on a hard surface or elevated so that those vents are not blocked or restricted. Carpet and things that are placed under the computer can block those vents.
  6. If there is a good circulation of air in the room, the temperature will be consistent through-out that circulation’s air movement. A large Ceiling Fan causing a breeze around your computer assures that the computer will have fresh air around it all of the time. You do not want heat to build you around your computer. If a fresh supply of air is not available to your computer’s air intakes, generate one.
  7. A computer should be placed in a cool stable low traffic area. Vibrations, bumps, and falls can damage it.
  8. Food, drinks, arms, butts, and other stuff does not belong on your computer. It is not a table or a chair. Spills kill, arms and butts accidently turn computers off and bend metal, and obstructions block vents.
  9. Most computer’s manufacturers recommended operating environments are typical between 50º to 95ºF (10º to 35ºC) with a good circulation of clean air.

Designing a well-engineered cooling system is not that hard to do, but it doesn’t just fall together. You have to think about it and develop a plan, then build and test it.

A custom made cooling tray for the HDDs. This works a lot better than the stock tray.
It holds more drives, and positions them directly in front of the cooling fan.

How to test your cooling:
You can install and use programs like PC Wizard, or your main board utility; but they may only give you only some of the information you want. Or you can get real serious and install temperature probes hooked to a control panel. If I think a customer’s computer has a heat problem, after use, I turn off the computer and touch the parts that may be getting too hot (listed above in line”6”). If you doubt the integrity of a sensor or there is a lack of one, you ether use touch (ultra low tech), or if you have the money to go high tech, you can install temperature sensors, or buy a portable Dot Laser Sighting Infrared Thermometer for around 50 dollars. Whither you check the temperature with a sensor, or by pointing a Dot Laser Sighting Infrared Thermometer; the closer you can get the dot or sensor to the heat source, the more accurate the measurement will be. In order to get an accurate read, the spot you choose to measure the temperature at, must be made of a material that conducts heat from the source well.

Sometimes it’s not the cooler’s fault:
There are many things you can do to improve your CPU cooler and maximize its efficiency:
  1. Use good heat sink compound and install the cooler correctly; too much, too little, poor quality, or badly applied compound will transfer heat poorly.
  2. Sometimes, removing the dust from the cooler is not enough to call it clean; over time, contaminates from the atmosphere can coat your cooler and insulate it from its airflow. Tarnished metal and sticky coatings like smoke film are good examples of this problem. Your cooler should be thoroughly cleaned if it starts to loose is shiny look. A cooler will only run at peak efficiency if it is clean..
  3. Use a fan or fan system and a cooler that is designed to easily do the job you need them to do (fit and function). This means that the CPU cooling system's air flow, size, design, and orientation needs to work well with the CPU and the case cooling system's design and configuration.
  4. Design Case airflow to give cool fresh air to the hotter running parts; Recirculating hot air is not a smart design.


Air-flow volume:
The Cubic Feet per Minute (CFM) is the volume of air the fan can move with no opposition to the flow; Filters and the CPUs cooling fins are obstructions to this air flow. The more dense the CPU’s cooler construction is, the more of an obstruction it is to the flow. This is a good thing because the more “air to fin” contact, the more heat will be carried away. The down side to this is a more powerful fan is needed to maintain a good volume of air flow. For case flow, you do not need a hurricane moving through your computer to keep it cool. There are two places that generate a lot of heat, the CPU and the GPU. Deliver a sufficient volume of cool air to their coolers air in-take, and then remove the hot air right after it exits the cooler; this will give you lower temperatures inside your case. The hard drives, North Bridge, memory, and power supply needs air flowing past them. If you have a lot of memory or you over-clock, you may also need some small fans over the North Bridge and/or the memory. Check the temperatures; if it’s hot, fix the problem.

Static Pressure:
This is a fan’s ability to compress air. Look at it as a fans ability to maintain a sufficient air flow velocity in spite of the flow obstruction like a heat radiating device that a fan would be trying to push air through. Fan manufacturers do make fans that are designed to do this well. Static Pressure is measured by taking a pressure reading while the air flow is restricted down to zero CFM. On a case fan, the level of this feature is not as important unless filters are used. Keep this in mind when choosing a fan for a given job.

The Cubic Feet per Minute (CFM), diameter, its connections pin number, and noise level, are the main features people look at when deciding what fan they need. But, there is a lot more than that to picking the best fan for a particular application. The fan’s blade size, blade design, and blade configuration determine the fan’s efficiency, noise level, and the RPM it works best at. The fan’s diameter and thickness also directly affects CFMs at given RPMs. Bigger fans move more air at a lower amperage while making less noise (this is useful info when designing a quiet system). Smaller fans can move less air at a similar RPM (revolutions per minute). On similar size fans, the faster the RPMs of the fan, the louder it is, and the more air it moves.
• Fan size – 200mm,***RPM –- 700 RPM,***Air Flow – 110 CFM,***Noise Level – 19dBA
• Fan size – 120mm,***RPM – 1900 RPM,***Air Flow – 110 CFM,***Noise Level – 37dBA
• Fan size – 80mm,****RPM – 5700 RPM,***Air Flow – 84 CFM,****Noise Level – 55dBA
• Fan size – 80mm,****RPM – 1900 RPM,***Air Flow – 24 CFM,****Noise Level – 21dBA
The above examples are just that, examples. Not every 80mm fan puts out 24 CFM at 1900 RPM: the reason; blade “size and design” and motor size. There is also one more very important factor to conceder when buying a motor; amp rating. Generally, a 120mm fan motor that is rated for the same RPM and a higher amp rating, will handle a load easier (its CFM rating is effected less by an air-flow obstruction) than the motor with the lesser amp rating.

The Cooling Fans Wire Color Code:
• PIN: 1*****FUNCTION: Ground******************WIRE COLOR: Black or Blue
• PIN: 2*****FUNCTION: up to +12vdc*************WIRE COLOR: Red or Yellow
• PIN: 3*****FUNCTION: Fan Speed Sensor*********WIRE COLOR: Yellow White Blue or Green
• PIN: 4*****FUNCTION: PWM Control *************WIRE COLOR: Blue
Pins 1 and 2 provide power to the fan. Pin 3 is where the RPMs can be read from (how fast it is going). Pin 4 is where the speed of the fan can be controlled with a 5 volt PWM signal. Pin 1 and pin 3 have a connector guide next to their pin hole. Fans with a 3 pin connector do not have the controllability function, but the RPMs are still trackable, A fan with a 2 pin connector is just a fan, it has neither track-ability nor controllability built in. The above Wire color code is the standard, the preferred color is the first one listed. But some retail Store and industrial computers do not adhere to the standard, they use proprietary fans. DELL’s proprietary fans have a different connector with a different wiring order, but the fans themselves adhere to the standard.

Lets look at two different blade designs.
  • Spayed air: These blades look simple with rounded edges and the blade is basically pretty flat. It is designed to move air from in front of the fan to behind it. Volume is the only concern.
  • Focused air: These blades look highly engineered. The blade’s pitch angle progressively decreases as it moves away from the center of the fan. These blades are shaped to focus the air flow toward the middle of each blade. Focusing the air flow in this way will greatly increase the fan's static pressure, and flow velocity.
Most fans are somewhere in-between these two extremes. Now that you know this. Run a fan out of the case. move your finger back and forth in front of the running fan. You can feel where the flow is concentrated. This will give you a better idea on where the fan is useful to you. To the fans that move the hot air out of the case or supply air toward coolers, blade design maters little. But, Simply moving air by a hot component will do little for it, the air needs to brush it. For this purpose, to make a good fan choice, knowing the flow characteristics is important. Because of the higher static pressure, the coolers them-selves also run colder with focused air. Your only hint at this when buying a fan is to find a good picture of the fan and look at the blade design.

The type of bearing your fan uses affects more than just its performance and the amount of noise it makes. There are three basic types our fans use; Ball Bearings, Sleeve, and sleeves with grooves. Be mind-full of you needs; you do not need ball bearings on a low RPM, cool running 200mm fan. If a fan makes unfamiliar noises, replace it before it fails.
  1. Ball Bearing fans are the best and most expensive standard type of bearing. Because they are the freest flowing, they are the most efficient performer and are the preferred bearing for high performance and high out-putt fans. They are made with metal or ceramic balls that travel in two lubricated grooves that are cut into inner and outer sleeves call a race. They're the quietest bearing, and their lifespan is normally over 60,000 hours at 50 °C. Ball Bearings are larger, more complex, and fair hot conditions better than any other type of fan bearing. And they work well when mounted in any orientation they need to be used in.
  2. Sleeve bearing fans are the cheapest, they often use two porous metal sleeves lubricated with oil or grease. They are self-lubricating, but the lubrication does not last forever. Re-lubrication is possible on some fans. The sleeve bearings are less durable at higher temperatures because this dries the lubricant up. Sleeve bearings also wear a lot faster when mounted in any orientation other than vertical. Their lifespan is normally around 30,000 hours at 50 °C.
  3. Rifle bearings are sleeve bearings that have a spiral groove in the contact surface that pumps lubricating fluid from a reservoir. Fluid Dynamic Bearings, and Hydro Dynamic Bearings are similar, but the grooves are cut differently. They fair hot conditions almost as well as ball bearings. Their cost, operating noise levels, and lifespans are similar to ball bearings, and they can be mounted in any orientation they need to be used in.
  4. Magnetic bearing fans do not really have bearings at all. There is no surface contact, therefore no bearing noise; the shaft floats in a magnetic field. This is the most free flowing, quietest, efficient, and expensive system available. This fan can be mounted into any orientation. The fan's life is so long because the bearing does not wear; the life span is determined by magnetic and electronic wear. They are not yet widely used because only a few low CFM models are available. This fan's Achilles Hill is the low out-putt that its design limitations confine it to.

Fan plug receptacle amp draw limits:
The main board’s CPU fan receptacle has a 1 amp limit. This is the limit of the current carrying capacity of the metal etching on the printed circuit board. On my Main Board, violating this limit with a 1.3 amp fan caused the BIOS to reset a few times before I figured what the problem was, but I was lucky, it could have damaged my main board. All of the other main board fan receptacles also have the same 1 amp limit, but powerful fans are rarely needed on them. If your CPU cooling fan (or fans) will exceed this 1 amp limit, you will need to use ether a special power connection adapter, or an add-on fan controller. Fan controllers have their current limitations posted in their specifications. On the special power connection adapters, pins 1&2 connect directly from the fan, to the power supply through a IDE Molex connector, and pins 3&4 connect to the CPU fan receptacle (on the main board) or a controller. This type of adapter has the highest limit; it’s normally limited only by the wire gauge of the connecting wire. If you only have the fan’s wattage and you need to know the amp draw, use this equation; watts/volts = amps. The fans we use are made to run on 12 volts. 5 volt cooling fans are available, but used mostly in industrial applications, I doubt you will ever see one. A fan draws the current that it needs, if the fan's needs exceed the current capacity of the circuit, the limiting (weakest) part of the circuit will overheat. Our fan's speed is controlled in two ways "voltage pulse duration" or " amount of voltage". The current should never be limited, the fan should always be provided with access to what ever it needs.

On the adaptor,
if you use more than one fan, the 3rd pin on the main board's CPU fan receptacle is the RPM sensor. It has to be connected to at least one fan on the computer or it will stop on "no CPU fan" during boot-up. If you want the signal it is receiving to make sense, connect it to one of those fans in the set. The RPMs will be read from this fan. The 4th pin on the main board's CPU fan receptacle is speed control, and needs to be connected to every fan in the set. Pins 1&2 still connect directly from all of the fans, to the power supply through a SATA or IDE Molex connector. Most over-clocking main boards have automatic CPU temperature sensing fan speed controls with adjustable parameters (some adjust in the BIOS, and some use main board tool utilities). I, personally, try to use as few connectors as possible. If you have control problems with you multi PWM fan hub, some PWM fans have a huge power draw or operate on an incompatible frequency. Generally, these types of fans can not be used on this hub. Unless you know how to build a circuit to circumvent this problem, using different fans or a fan controller (with the problem fans) is the only alterative.

Speed Controls:
Some motherboards 4 pin fan headers are only there to facilitate the use of up to a 4 pin fan. Do not make the mistake of assuming these fan headers have PWM control; some have voltage control through pins 1 and 2, some have a straight 5 volts at pin 4 to quiet the fan, and some have no control ability, RPM signal, or "pin 4 voltage" at all. To find out about the capabilities of your header, read your Main board's manual. PWM controlled headers are labeled PWM.
PWM control- (Pulse-width modulation). This method requires a 4 pin PWM fan. The way PWM works is; the fan control modulates the width of the trigger pulse’s duty cycle that is sent to the fan plug’s pin 4. A duty cycle is the percentage of one pulse in which this square wave trigger is at an active (5 volt) level. The fan’s applied power (12 volts) mimics this (5 volt, 25 kHz) trigger. This means that If the square wave trigger’s 5 volt duty cycle is 40% of the pulse, 12 volts powers the motor for the duration of this duty cycle, then turns the motor off for 60% of this time because the trigger is at 0 volts. This causes the motor to run at 40% of its maximum speed. Simply put: pin 4’s trigger turns the fan’s motor on and off 25000 times per second (25 kHz); The longer the switch is on compared to the off time, the faster the fan goes. Because the full voltage, current, and torque is always available to the motor at any speed, the motor runs better, cooler, and quieter. If the power connections come directly from the power supply; one PWM control signal can simultaneously control several PWM fans, and there is no limit to the current it can control. PWM control is, by far, my preferred choice.
Voltage control- The best feature of this control is, it works on any fan (2 , 3, and 4 pin fans). This system adjust (with a variable trigger) the voltage that is going to the motor in pins 1 and 2 by turning it into heat; the slower the motor, the more heat. It accomplishes this one of two ways, it uses a rheostat as a variable resistor OR a rectifier or transistor (with a heat sink). Both limit the voltage that is available to the motor. This control's current rating (amperage, wattage) is determined by the amount of heat that the system can safely dissipate with-out overheating. This type of circuit works well at medium to high speeds, but produces a lot of heat as it limits voltage, is inefficient, has very poor low-speed control, and adds more heat inside your case. The transistor method is the best of this type because it has a lesser extent of the same flaws. Through a transistor; a smaller variable trigger voltage controls a larger voltage and amperage. The larger voltage mimics the smaller trigger.

There is no perfect filter. It ether has great filtration and poor airflow, poor filtration and great airflow, or a compromise somewhere in-betweens these two extremes. All filters restrict flow: the better the filtration, the more restrictive they are. There are some tricks that we can use to get around this to some degree. If you use a very large filtration area, you can have very good filtration and yet still have a satisfyingly fast airflow. There are several ways of doing this, the greater the surface area, the more effectively this works. Great (restrictive) filtration needs its poor airflow offset with a powerful fan. The below listed is not all that is out there, but this will point you in the right direction.

Screen: The screen filters that come with your case kill 20 to 30% of the fans airflow even when they are clean. There are a few problems with them; When clean, they filter air poorly. When they are dirty, air even has trouble getting through, and they get dirty pretty fast.
Paper: Paper filters have superior micron filtering capabilities. But they are too restrictive, get clogged up with dust way too easy, and are not made to be reused. They can be mounted as a fan fold to increase the filtration area and flow, but this only helps a little.
Mat:The thicker filters like the "EZ Flow Green Air Filters" are the (all around) best. You can buy kits in different thicknesses, then cut it to size. The thing I really like about these green filters is, when they get a little dirty, they still have great flow, and they are reusable (able to be cleaned). There thickness is a problem sometimes, but they will fit in most places. It work so well because its thick fibrous filtration mat gives this stuff a very large filtration area. A carbon filter is also a thick black filtration mat that is a lot like the green one. If it has activated charcoal, it also removes some chemicals from the air, but it has a life span because it has a saturation point. As you can see, these mats can be made from lots of different materials.

There is another way, go to the source. With a great Air Purifier for your room or house, you do not have to worry about cleaning restrictive case fan filters, powerful case fans, or any of the problems the case fan filters create. You will rarely even need to clean the dust from your computer. A good one cost several hundred dollars. If you have breathing problems, or an extremely dusty house, it is well worth the money.
Air Purifier, Ozone Generator : If this Ozone Generator is working at an effective level, it is unhealthy to use. Do not buy one of these.
Water Air Purifier: The ultimate filter is an aerator in water, the air that comes out of that system is pure and cool, but humid. The air is feed by a compressor. The water Air Purifier system cost about the same as an Ozone Generator, but it is comparatively noisy. The water gets nasty quick and will make you sick if it is not changed often.
Multiple stage Air Purifier: This type of air filtration is done in several steps; rough first, finest last. This is another way of spreading the filtration out over a very large area. It is not as expensive to buy as the others, but you will go through a lot of filters.

This is an EZ Flow Green Air Filter on the front of a LianLi case.

Positive and Negative Case Pressure:
If you have a hole like a vent where there is no fan, or slot covers with big holes in them, a lot of the air in your case will follow the path of least resistance. If the case has positive case pressure; this air outlet should be next to a cooling fan that needs a place for its hot air to exit the case . Or, if the case has negative case pressure, air is pulled into this hole next to a cooling fan that needs a supply of fresh cool air. As you can see, either way, the behavior caused by the case pressure should be part of the cooling plan.

Many enthusiast are “negative case pressure" haters because the air drawn into the case from everywhere it leaks, is unfiltered. The problem with unfiltered air is, you will occasionally need to disassemble and clean your computer to keep it from getting dirty and overheating. If you have a dust free house, none of this matters.

The problem with positive case pressure is, for its advantages to be effective, all intake fans must have filters on them. These intake fans need to run strong to counteract the filters opposition to the fan's air flow. The good side is, the high positive pressure of filtered air in your case, will let your computer run cleaner, the case output fans (including in the power supply) will run faster, and filtered air will leak from your case (this keeps dust out). The maintenance is simple but often; you must clean the filters on a regular basis. Keeping these filters clean is very important because there is a point to where the case's pressure will go negative as they get dirtier. When this happens, dust will enter your computer and a layer of it will coat your coolers and insolate the fan's air flow from them (this is what you are trying to prevent). The higher the positive case pressure, the more time you have before it reaches this point. No "filter" filters out everything, so on rare occasions, you will still need to disassemble and clean your computer.

Making it look good (cord management):
If you wish to extend a cord, you can find a great match by buying broken or cheep stuff on EBay. I wrap fan wires around a thin screw driver shaft, then remove the shaft. This turns them into a spiral cord. If you did a good job on the splice (solder/heat shrink), it disappears into the spiral cord. This makes every cord the perfect length. My builds look nice and neat, I show them off often. I've never had anyone comment on a splice, but they do ask how I did the spiral cord.

I've also known builders that made all of there cords a custom fit. To cover the splice, they use cord covers like you see on high-end Power Supply cords. They remove the pins out of the connector, cut the cover to fit then slide it over the wires, then reinstall the connector. Some of the better fans come with this cord cover, this makes customization easy. Spiral Wrap Tubing and other plastic cord covers are not pictured, but can also be used. You do not have to remove the connector to install it, but they don't look as good. Anyone that is this anal about their cords would NEVER use an prefabricated extension. tongue.gif


A Push Pull Fan configuration:
A Fan Stack is where you have one fan stacked on another, then mounted to a device. For a Push-pull configuration, we must have a unit in-between the two fans that we are moving air through as a function of cooling that unit. This is popular because, if you have room to install two fans (one at the entrance and one at the exit of the CPU cooler), it is a great way of increasing the air-flow without increasing the noise. It’s like using a thicker larger fan; you’re literally doubling the size of the prop and motor. The cooling fins of a heat sink are an obstruction to the fan’s airflow; the second fan reduces this obstruction’s ability to slow down the airflow. This, in turn, increases the airflow and its cooling effect by allowing both fans to run at a slightly higher RPM because there is less of a load on each fan. In this stacked fan configuration, the fans will run quieter and cooler, and last longer. For a Push Pull Fan configuration, it is best to use identical fans, or at least ones that are very close in size and performance.

Not all fans are good for all things. Some are optimized only at moving air, and some are optimized for pushing air through obstructions. If you have two similar fans that have the same CFM and top RPM, the one with the higher amp draw is comparatively optimized to better propel air through obstructions. But, you can make a stack or push-pull configuration out of two fans that are optimized for moving air; together, they often will do well at moving air through an obstruction. Where-as apart, due to their poor static pressure, they would do poorly at this task.

The Push Pull fan configuration has three problems.
  1. Wasted potential. A fan is engineered for the fan blades pitch and size to be compatible with the motor’s power abilities at its rated RPMs as it is being used as a single fan, each part of the fan needs to be a good fit for its job; this is a "balanced architecture". Fans are not designed to be used in a stacked configuration, this is why you will often see very little improvement ( one to three degrees) in the cooler's performance by adding a second fan. A single fan, with the same specifications (fan blade area and power usage) as a Push Pull Fan configuration, will easily outperform that configuration. If more of a fan is needed in your system; performance wise, up-grading the fan is a better choice.
  2. Insufficient installation space. Not all cases have room for the thickness of a stack with two fans plus a cooler or Radiator: The Corsair H100i liquid cooling Radiator is 27mm thick, with 2 x 25mm fans, that's 78mm (over 3 inches) thick total. (5" x 10" x 3" = 150") 150 cubic inches is a lot of real-estate to give up inside your case; few have it to give. On most air coolers, if you are using gaming memory with tall heat sinks, there is not enough room to put a second fan on the memory side of the CPU cooler. A set of 15mm thick 120mm fans may fit, but don’t use them, they’re way too weak (poor CFMs and static pressure). There are lots of things like “the main board’s component configuration" and "the case’s size and/or configuration” that can interfere with the installation of your fans and coolers. The case you use should be able to contain the whole system, a fan sticking out the top has the look of poor planning. Do the research before you buy; purchase hardware that fits where you need it to go and does what you need it to do.
  3. Special connections. The amp draw on 4 fans is too high for them too all be connected directly to the CPU fan header. Not to mention that it's a physical impossibility, adaptors or a fan controller must be used. If you use an adaptor that just connects to the header and fans, the fans may draw too much power. See "On the adaptor" above for tips on how to handle this problem.

The alternative is to use a 38mm fan instead with the H100i Radiator for a 66mm of total thickness. With the 38mm fan, you get basically the same benefits as the 25mm push pull fans in a thinner package. This is because 38mm fans comparatively have a much larger fan blade and motor size. The difference is, most 25mm push pull fan configurations do not need to have their speed regulated to be some-what quiet, most 38mm fans need to have their speed regulated with a controller to keep them from being too noisy. Most good main boards can do this in the BIOS or their windows control panel. The good side is, when throttled up, most 38mm fans have a much faster airflow than most 25mm fan push pull configurations are capable of.

A liquid cooling system:
A liquid cooling system is, without a doubt, the highest performance cooling system available. They are efficient, they absorb heat from the component they protect, and release it outside of the case. It needs cleaning, maintenance, and checks a lot like any other cooling system. It does have a few extra down sides though.

There are four problems with liquid cooling systems:
  1. If the pump fails, the protected components will, all of the sudden have no cooling. If the fan fails on an air cooled system, it will at least passively cool the item it is protecting. You can use a flow meter to protect your system against this, but they are expencive.
  2. If the system springs a leak, it can cost you a very expensive computer. You may think your safe because you use a nonconductive fluid, but that isn’t safe ether; this fluid conducts electricity when it picks up contaminants inside the cooling system, as well as when it is mixed with dust, a smoke film, or any other contaminates that are already on the board during a leak. Nonconductive fluid is an expensive bad joke.
  3. Because of its complexity, it is more difficult to install, there is more that can go wrong, and it’s less reliable.
  4. This type of system can be very expensive ($200 to $500). You can also buy a less expensive sealed preassembled system for under $150, but only the better ones are worth the extra trouble and expense.

Graphic cards:
The graphic cards normally use one of these two cooling systems, but liquid cooling is a rarely used 3rd option. System number one uses a 2 or 3 fan cooling system that blows larger amounts of fresh air more directly across the cooling radiator. This system is better, but because the hot air exits into the case, it should only be used in cases with good air flow. System number two uses a cooling system that exits the hot air out the back of the case. This system is popular in fan-less cases because it runs more quietly as the graphic card’s fan uses the case’s hot air to try and cool the graphic card’s heat sink. Of course, you can tell by my sarcasm, that I recommend cases with good air flow for ether system.

Why do power users not trust CPU factory coolers, but don't even bother to look at their GPU's cooling management. I, personally, don't like the factory fan management settings because they are set to let the GPU run too hot. On most systems, they also never let the fan go above 60%; this is a waste of this cooling system's potential. If you are unhappy with the way your graphic card is managing its own fan, adjustment utilities (like driver controls) are available.


A quiet computer:
I’ve seen many enthusiasts fill their computer with low RPM 25mm thick 120mm fans so they will have a quiet computer; in my opinion, this is a big mistake. This is OK for checking your E-Mail, but it’s a bad set up for a power-user (like for instance a gamer or over-clocker). Every CPU I’ve seen that frequently went over 150°F (66°C), had a short life. Quiet is great, but not at the expense of performance and reliability. Using temperature sensing fan speed controls and strong fans will give you the best of both worlds. With this scenario, the computer will normally run very quietly, but during extreme use, the cooling system has the ability to rise to the occasion and do its job. A CPU cooler’s cooling ability hinges on the coolers efficiently and the volume, and temperature of air going through it. If you want your computer to have a quiet cooling system, start with a great CPU heat sink (cooler), then use a fan that can easily move a lot of air at a reasonably low RPM. Thicker, large diameter fans, with a higher amp rating, can move more air at lower RPMs, therefore quieter. Also, use a fan that can max out at a high enough RPM to move a sufficient amount of air to quickly remove the heat from the CPU’s cooler when the need arises. Used correctly, you will probably never hear this fan. But under extreme CPU use, the RPMs will rise, and it will fight hard to keep your CPU cool. Most over-clocking main boards have automatic CPU temperature sensing fan speed controls with adjustable parameters (some adjust in the BIOS, and some use utilities). I bought a 6 fan speed control that connects to the 4 pin CPU fan plug receptacle on the main board. This fan controller now automatically controls every fan in the case. Nvidia has a performance tool that installs a video card fan control into the driver control panel. It’s the best I’ve ever seen, you can set up the “GPU temperature” to “cooling fan RPM” ratios on a graph. It’s on Nvidia’s find a driver web page.

My philosophy:
On the case itself, I use quiet fans with an acceptable amount of air-flow (50 to 80 CFM). Internally, on the CPU cooler, I always use a powerful 4 pin Cooling Fan with Pulse Width Modulation (PWM). Each device needs to be a good fit for its job. On a gaming computer’s CPU, I use an aftermarket cooler that will take around a 130 CFM, 120mm 4 pin fan. The 4 pin connector on this fan and a compatible main board will allow you to adjust the minimum RPM and the target temperature. A 38 mm thick fan’s larger blade size lets it move lots of air at lower RPMs. With a fan like this mounted on a 120mm cooler, and running at 50% of its maximum RPM on an overclocked high dollar CPU, I set the target temperature at 122°F (50°C) and I never hear this fan. Almost all main boards will allow fans up to one amp on the CPU fan plug, so with extra hardware or adapters, a powerful fan is perfect for drastically improving a single fan cooler. At higher RPMs, a fan can get loud, but does so only when the CPU is clocked high and/or ran hard. If kept under 150°F, a high dollar CPU will have a longer life and will run well. I like my computer to be quiet, but I don’t want to compromise the cooling; a fan of this type gives me the best of both worlds. With a cooling system like this, a high dollar CPU like an i7 will never see 140°F. Using a low to mid performance fan, will turn a great cooler into a low to mid performance Cooler; you will have limited the cooler’s ability to cool the CPU because that cooling system can quickly reach a point to where it cannot remove the heat as fast as it is being generated. If you are running a hot CPU, it's better to have over-kill type airflow available, than to come up short (too much is better that not enough).

Upgrading to a quality, high performance fan can greatly improve your CPU's cooler. This fan is 38mm x 120mm.
This computer has an i7 2600K with 16GB of Corsair Vengeance 1600MHz DDR3 memory

There are two sides to every coin. The good thing is also a bad thing; all 38 mm thick High CFM fans, and the cooler they go on, are big and heavy. When I installed a cooling system like this in my i7 equipped gaming rig (pictured above), I mounted the case fan and the cooler’s fan in my computer so they blows air toward my memory which also keeps it cool. I had to do this because the heat sinks on the memory were too tall for me to mount the fan on the memory side of the cooler. I normally like to configure my fans to blow air out the back of my case, but to use this fan and cooler; I had to make a compromise. Not all compromises turn out bad. The two 120mm fans mounted in the top of my case quickly exits the hot air.

This is an upgraded 25mm thick 120mm fan on a Xigmatek Dark Knight. It cools an overclocked Intel QX9650.

A hard core over-clockers mentality is different from the way most power users use their computers, they are often extreme experimenters. Most power users are not like this, they over-clock to get better performance and take more of an advantage of a processors potential. My hope is that my perspective may be useful to other that run across this. The Intel i7 2600k I have is a very powerful CPU, very few people have need to over-clock it to its maximum potential. At 4.2 GHz, my CPU rarely goes over 120°F, and is very fast.

The world is full of things that have a performance curve that nearly flat lines at higher performance levels. CPU GPU and memory frequencies and fan air flow volumes get to a point to where further increases provide almost no additional benefit. There is a sweet spot in between improved performance and excess electronic wear and noise. Also, A candle that burns brightly has a short life. And like-wise, hardware that is used at its maximum potential also lives a short life. Use your hardware at reasonable and sustainable performance levels.

Heat problems in a Manufactured Computer:
Inside the average Compaq, you will find a very hot hard drive. That can’t be good for it. These Retail Store Computers (RSC) must have been designed to go in a very cool air conditioned office, which most will never see. You do not need a fan blowing directly on the hard drive to keep it cool, you only have to keep it from sitting and cooking in its own hot air; air must at least brush by it. The problem you see at the hard drive is only the tip of the ice burg. The RSC’s poor air-flow also causes problems in the CPU, north bridge, memory, Graphics card , and power supply. It will take some modifications and some ingenuity, but most RSC’s heat problems can be fixed. Open it up and take a look to see what you have to work with. Come up with a plan, order the fans, fix it and test it. After you fix the many heat problems you will find in your Retail Store Computer, It will last longer and run better. Heat problems appear to be the manufacturer's way of managing how long their computers will last, they are designed to last about 3 years. This is also the amount of time an unmaintained lightly used operating system will last.

This is a DELL T3400, I installed a 60mm fan over the North Bridge using creatively bent fence wire.
The large CPU cooler you see on the right edge of the picture is feed by a 38x120mm 140CFM PWM fan.

When you buy an industrial or gaming "manufactured" computer, you expect better quality because you paid a lot of money for it. The DELL T3400 is a great business computer, but I have found two big things I dislike about them. They're picky about the memory they use, but if you have read the specifications, this is no surprise. The other problem is the north bridge runs hot. The amount and type of memory used deeply effects this heat issue. Eventually this causes the video controller in the north bridge to fail. You can tell the heat has taken its toll when replacing the graphic card with a known good card does not repair the "no video" problem the computer is having. This Main board failure could have been prevented. If you occasional check the hot spots inside the systems box, you can often find problems like this and fix them before they become a costly issue. The fix can be anything from a good cleaning or making some adjustments, to adding or upgrading a fan. In the case of the T3400, adding a 60mm fan to the north bridge fixes the problem.


This brings us to the last subject, maintenance:
Where you place the computer, what is in it, and how you use it will determine how often it needs to be cleaned. By occasional checking your computer, you will eventually configure an appropriately timed maintenance schedule. During the checks, look for and remove dust from the computer, inside and out. A compressor or canned air is useful for this.(see NOTE-1 & 2). Check for corrosion or a built up chemical film covering the metal on your heat sinks. The chemical film is caused by things like smoke and other chemicals that float in the air. Clean the film off by using a Q-tips with a little cleaner on it, and then dry it with Q-tips or compressed air. If you are worried about the cleaner getting on your main board, wrap a towel around the base of the CPU to keep the electronics dry. Sometimes the only way a heat sink can be cleaned properly is for it to remove it from the computer, soaked, brushed and washed then dried. When copper starts looking tarnished, that layer of corrosion acts as an insulator. After soaking it in Tarn-X (and then washing it), it does a much better job of keeping the CPU cool. If you detach the heat sink from the CPU, before you reinstall it, wipe off the old thermal paste and put some fresh stuff on.

Unbalanced dusty fans wear faster, so I clean the dust off of my fans with compressed air and a few damp Q-tips. If the fan is already making unpleasant noises, lubricating it will only prolong its inevitable replacement. If your fan is near the end of its life, it will never operating at its peak performance levels again. Fans are cheap when compared to the hardware that they protect, so It is wise to replace one at the first sign of problems.
Even if there are instructions and provisions for it, no one lubricates a good running fan, but there is no good reason for you not to. People normally use a fan till it shows signs of wear, then they replace it. If you have an expensive fan that you want to last forever, it does need to be on a maintenance schedule. What type lube should you use?? Oil is extremely temporary as a fan lubricant because it evaporates too quick. Standard grease is worse because it's too thick and as it dries, it gets thicker and becomes a tar like substance. They do make good fan lubricants, but you need to buy the right one. You need to buy something that is in-between oil and grease, something that will not evaporate and will take a long time to dry out. How often do I lubricate my fan?? Too often is better; use a high grade lubricant, and replace it before it dries out.

NOTE-1: If your cooling system is barely good enough to do its job, clean it often. When it gets just a little dirty, it does its job poorly. Heat damage is progressive and is often unseen until it’s too late.
NOTE-2: Never use a vacuum cleaner inside your computer. The hose has a large amount of static electricity created at the suction nozzle; a static discharge from that nozzle can destroy your computer’s sensitive electronics.


Question: I am running the same i7 2600K... Mine runs hot... up to 190°F at times...the Only heat issue I have is my CPU. The build was finished by someone I trusted .... I keep my office at 68°F and it is in the line of flow from my AC, all my fans are filtered but the CPU gets Real Hot... But Only when I am on line thru the wireless unit... Any advice would be Greatly appreciated, and Wireless is my only option here. my airflow is Good my office is cool and the equipment is cleaned every few days (blown out)

Solution: 190°F is way too hot. The wireless unit stressing your CPU is not the problem. The CPU appearing to get hot when it is stressed is the problem. This dilemma could be a sensor problem, but is most likely a heat problem. Choose the one of the two below that fits the best, then proceed.
  • If the cooler just feels slightly warm near the CPU when the sensor reads 190°F, the temperature sensor is ether not reading correctly, or the cooler was incorrectly installed. Remove, clean, and correctly reinstall the CPU cooler. Use good heat sink compound. Poor surface contact can be caused by something as simple as a grain of sand between the CPU and its cooler. Once you know that there is not a heat transfer problem, If the cooler still just feels slightly warm when the CPU reads hot, the sensor is wrong. Live with it or install a better sensor. If the CPU is truly at 190°F and you have good heat transfer, the cooler should be more than uncomfortably hot.
  • If the cooler feels appropriately hot near the CPU when the sensor reads 190°F, check the cooler's air flow to see if the CPU fan is weak. If the CPU fan is a 4 pin PWM fan, check to see that the fan speed is not adjusted too low. If the cooler's air flow is still weak, up-grade the fan. You may try experimenting with the case fan configuration to assure that the CPU fan has a contentious supply of fresh cool air. The CPU and memory needs to be compatible with that main board's BIOS version. The CPU and memory also needs to have been set up correctly in the BIOS. If all in the above list checks good; up-grade the CPU's cooling system. Reread this guide a few times, it will give you some more ideas on how to make improvements.

Many thanks to “The Surveyor” who sent me this picture of his computer and shared his problem with us.
This Intel 2600K CPU that is under this small cooler has 8 logical processors that operate at 3.4 to 3.8 ghz.

High end main boards like this, have heat sinks and memory that form a cavity around the CPU socket. A low profile CPU cooler will not work well in this hot enclosed area. A cooler that brings the CPU’s heat up out of this pocket before it is vented away, will help this entire area to run cooler. I also advised him to turn the back fan to blow fresh air into the case. This will cause fresher air to flow through the CPU cooler's area; fresh air in from the back fan, and hot air out through the top fan. The back fan advice helped a little, but not enough. I then suggested that he down-clock the CPU until the cooler gets up-graded. The owner will be installing a water cooling system in this computer when it arrives. This is a great choice, there is plenty of room for it in that case.

Question: Why does my computer keep blue screening?

Solution: A blue screen happens when the Operating system has an error that it could not recover from. This can be caused by anything that has to do with file transfer storage or processing.
Normally it is caused by;
  1. A program is performing an illegal operation, or is having compatibility issues. This includes Viruses,Trojans and poorly constructed program code.
  2. The operating system or a program having bad or missing files or a Hard Drive using bad sectors.
  3. An incompatible or corrupted driver.
  4. A Hard drive is overheating, or it has a power-cable or data-cable problem.
  5. Memory is overheating, bad, or needs their connections cleaned. Incorrect Memory settings in the BIOS.
  6. The CPU or graphics card is bad, starving (not enough amps), overheating, or its contracts are dirty. Incorrect CPU settings in the BIOS.
  7. Insufficient wattage from the power supply (current starvation), If your Power Supply has more than one 12 volt rail, you may not have the wattage load correctly distributed to each rail.
This customer had paid a computer shop $60 to be told that they reset his graphics card and cleaned its connections. I was called because this did not fix the problem. I found that there was a mat of dust a fourth of an inch thick between the CPU cooler and its fan. This caused the CPU to overheat. A good cleaning fixed the problem. Cleaning the operating system and blowing out the inside of the computer fixes more than half of the calls I go on. If this would not have fixed it, I would have looked in the Event Log In the OS. An overheated device, a bad SATA data cable, and a dirty (cluttered, damaged, and/or unmaintained) operating system are the most likely suspects.

Question: What do you guys recommend for control? I am having difficulty figuring out how to adequately power 30 3.24A fans? Just a few of the swiftech 8way pwm dongles, wiring the fans with a 4 pin pwm according to that previous post, and hooking up to a high watt fan controller work? Like the lamptron cf525 or what kind do i need?

Solution: I can see why you're having problems. We use PWM fans: Run pins 1 and 2 to a 12 volt lines coming from the power supply. If you have more than one fan, only one can connect to pin 3 (RPM sensor) on the header. On Pin 4, all fans go to the PWM fan header on the motherboard. For that many fans, If you use PWM control, you will need an amplifier to boost the current of the PWM signal. A voltage controller will need to handle at least 40watts per fan.

I like powerful fans, but a 3.24Amp fan in a computer is over the deep end. The idea behind using a PWM 38 mm thick fan, is the larger blade size and powerful motor lets it move lots of air and have great static pressure, even at the lower RPMs we normally use them at. If the motor is too powerful, this takes away from the large fan blade size and pitch, that we prize so highly. We like PWM 38 mm thick fans, that are around .5 to 1.6 amps because they have a good balance of motor and blade size and pitch, and the PWM makes them more controllable and easier to wire into the system.

The world is full of things that have a performance curve that nearly flat lines at higher performance levels. Fan air flow volumes get to a point to where further increases provide almost no additional benefit. As case fans, when the flow through the case is fast enough to where no hot air is being recirculated through the coolers inside the case, faster flow than that is useless (1000 to 1800 RPM). As a cooler fan, anything past the top of the performance curve is a waste (1800 to 2400 RPM). A 3.24Amp fan (5500 RPM) is extreme overkill for a computer; There are those that disagree, but they do so because they need raw power to get good air flow through dense coolers and filters, and they don't care about a lot of noise during normal usage. I see no place where 250CFMs would be of good use to me, and I DO care about the noise to CFM ratio. My reason for using 120 x 38mm fans is, they have more air flow at lower RPMs, therefor less noise during normal usage; yet if power and a lot more air flow is needed to bring temps down, I have that option available too.

The Lamptron CF525 is a voltage controller, and not will work well with the Swiftech 8way PWM controller because you will have massive wattage shortage problems and no PWM control. 30 fans x 12volts x 3.24Amps = 1166.4watts, use a really big power supply and manage the power. With 30 fans that strong, you should be able to hover the computer around the room.

Question: Doing a V config wouldnt be near as good as just using 2 fans on top pulling out. 2 push and 2 pull would definitely kill trying to teepee a fan set-up

Solution: I disagree. With four 80 CFM fans (2 push, 2 pull), you would have 160 CFM of air going through the radiator. With four 80 CFM fans in an enclosed V configuration (2 on each side), you would have 320 CFM of air going through the radiator. In the V config, you could run the fans at a lower, quieter RPM, and still have more air flow, there-for, a much cooling running system. This V configuration has one more big advantage; air flow velocities are not consistent across the surface of a fan unless there is a buffer space in-between the fan and the heat radiating device. The buffering abilities of the V configuration housing will provide a perfectly uniform flow across the entire radiator. This feature will enhance the system's efficiency. The only down side is the parallel (V config) system has a comparatively lower static pressure at any specific CFM when compared to the series (push-pull) system; but considering that the v config has twice the air flow velocity at the same RPM, you can maintaining a comparable static pressure by using a slightly higher CFM and yet still run lower system RPMs. On the first part of the drawing, the front is open so you can see the fan placement. But when finished, a cover goes there to seal that area. This will cause the unit to be a closed system except for input and output.

Question: I have two fans in the top of my case, One brings fresh air in to the CPU cooler, the other kicks the hot air out.

Solution: Putting an intake and an exhaust side by side creates a heat-loop. As a fan runs, there is a low pressure area behind the fan, and a high pressure area in front of it. If you put high pressure right next to low pressure, the high pressure area will always feed the low pressure area. This is what is happening inside AND outside of your case. The air is going in a basically closed circle. Of course the loop leaks, but not enough to prevent the problem.
There are the only three things that will intrude upon this loop:
  • Positive case pressure,
  • something in the path,
  • a good velocity of airflow across the top of the case.
Two are very bad because they feed hot air into the loop, and the other is very good because it feeds cool air into it. Unfortunately, you probably only have the bad ones. Positive case pressure feeds heat from the case into the loop and the air gets hotter and hotter and hotter. In your case, your CPU cooler is also right in that path. Considering how much heat a CPU produces, having its cooler as part of a heat-loop is not a good thing. You can test it if you want, but I have seen it tested many times. Putting intake and exhaust right next to each other is always a Bad choice. Both fans ether need to move air in the same direction, or one of the fans should to be removed or deactivated.

If you liked this guide, I have written others that you may also enjoy.
GPU and CPU power connections
How to Solder Electronics
How To Choose A LiPo Battery

Comments (15)

Great article. Bookmarking for future reference and recommendation. The note about using vacuum cleaners could even be bolded, as I'm sure there are users who would think to try it.
Thank you, I'm glad you found it useful, Feed back is always nice.
I even like constructive criticism, it will help me edit and improve this resource.

I work on a lot of computers, most of them that come to me have cooling system problems.
Even if you already know all this stuff, its good to use a list like this to double check your work.
When you're up to your butt in alligators,
sometimes it's difficult to remember to initial objective was to drain the swamp.
Coreda provided the Artwork that heads this article.
Great job dude, thanks for the contribution.
very nice article with lots of helpful and very good information. best article I have read on this subject, and I have read lots of them.
Thank you. A guide like this take a while to write.
Comments like yours make it well worth the effort.
Excellent article, I never really thought about the dust on the board causing shorts with water cooling. Guess I'm sticking with fans for now!
Thank you Scott.
Most PCs are cooled with "fan on metal radiator" cooling systems,
so you are in good company.
Distilled water is a classic example of a nonconductive fluid,
a few grains of salt will contaminate a whole gallon.
The air flowing through our cases leaves part of its self behind.
A swipe on most clean looking mother boards will turn the end of a damp q-tip, black.

I'm still adding more to this guide, it's work in progress.
I'm glad you found it useful.
Great read, I am running the same i7 2600K... Mine runs hot... up to 190 F at times... I have a cool master on it... (Not my choice but I work overseas and the build was finished by someone I trusted) the Only heat issue I have is my CPU... I keep my office at 68F and it is in the line of flow from my AC, all my fans are filtered but the CPU gets Real Hot... But Only when I am on line thru the wireless unit... Any advice would be Greatly appreciated, and Wireless is my only option here. my airflow is Good my office is cool and the equipment is cleaned every few days (blown out)
Great article. Thank you for the time and effort you put forth. Lots of people get a good cpu cooler and fan but don't think about getting cool air into the case and expelling the hot air. Then they wonder why they have high package temps etc......
Thank you both.
chrisjames61 ** The lack of fresh air outside the case, oh yes, I see this problem a lot.
The power supply is normally the first to go. The video card is next.

The Surveyor ** 190°F is a bit hot.
See troubleshooting section in the guide.
great stuff!
glad to see someone's willing to write something like this.

I hope folks would spend more of their time on reading an article like this, rather than asking what product should they buy
or simply did their homework on pointing out what to do to solve their problem.

nice write, Luke :thup:
I'm a research type guy myself, I download and read the manual before most purchases. I don't like surprises !!
People that do the research first, ask better questions, and more readily know the answer they need when they see it.
A fishing exposition, like most threads I see, needs to be the last step of the research, not the first.
“Chance favors the prepared mind” - Louis Pasteur.
Thank you for taking the time to read and comment on my article.
I'd like to share my findings during the curiosity of getting the best fans setup inside my PC case.

I found most fans were really sensitive about their intake "breathing space".
in most situation, our intake on the case should be mounted like this:

if the case has enough clearing or no obstructing mesh, then there's no problem.
but few cases had meshes.
I found that mesh tend to add additional noise to the fans placed directly behind it.
had test the fan in an open environment without noise, but every time I place it behind the mesh the fan will become noisy.

adding a shroud with a similar thickness with the fan eliminate the noise,
something like this:

the main disadvantage is of course the thickness.
removing the mesh can also help reducing the noise, but mechanical strength of the case will be compromised.

another interesting thing, is by having a fan close by to the cpu heatsink proved to be very beneficial to me.
I have a few drop in cpu temps by doing this setup:

I have two advantages by doing so, reducing the noise, and reducing the cpu temps too.

an intake fan, right in front of the cpu heatsink at the top of the case should be able to do so.
but I can't do this, since I'm using a very thick fan on the cpu heatsink.

it a bit late, but...
happy birthday Mr. Lott
Thanks, and Yes, this guide can be used on handheld gamepads also.
You can attach a cooling device to its back; like a fan or cooling block connected (with small hoses) to a water cooling system. But, anything attached will be restrictive and bothersome.

Having a fan blow toward it, is the only unobtrusive way. It will cool you as well.
Rather than it sitting there in your hot hands , and cooking in its own heat, the fan will brush the gamepad and your hands with cool fresh air and carry a lot of the heat away.
This principle is discussed in the guide in more than one place.
Example: Placement #6, close to the start. Also in the "Manufactured Computer" section, refereeing to HHDs
You are a wealth of information, Thanks for sharing that with us, the mesh is restrictive and does make noise.
But there is another way. If space is a problem, remove the mesh with a dremel, and use a grill on the fan instead of the mesh. Removing the mesh will compromise mechanical strength ONLY when the fan is not installed. If the mesh is removed, a fan is no longer optional at this vent, something ridged must be installed here.
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