Fan selection advice - What did I forget?

[RevGAM]

Please take a look at the following and let me know of any mistakes or omissions so that I can improve it, please! Thanks!

Copyrighted Images are owned by their respective creators. Sorry about the extra images at the end - the editor keeps adding them back in.

 

 

1. **Fan Sizes**: There are several different sizes of fans, from 40mm to over 200mm. The most common sizes on consumer PC cases,  graphics cards (GC) and coolers are 120 & 140mm, but you will also find 92mm, 180mm, 200mm and 220mm. 40, 80 and 92 are most likely to be found on small form factor (SFF) cases and Devices, 180mm and larger are mostly found on very wide cases, full towers and other very large cases. Look at the documentation for your case or device to determine what your choices are, and how many.
   
2. **Fan Types**: There are 3 common types of PC fans:
   1. standard fans that pull air through the blades,
   2. fans that pull air like a watermill in a circular chamber, often referred to as blowers,
      
   3. and AirJet (created by Frore Systems), which is solid-state. I know that sounds like an oxymoron but you'll believe it when you watch the LTT video! https://www.youtube.com/watch?v=vdD0yMS40a0
3. **RPM, Airflow and Static Pressure**: These are 3 critical factors. Think of airflow (AF) as movement, airflow determines how much air the fan can move, while static pressure(SP) is important if you have obstructions like heat-sinks or radiators in your case, so you can think of SP as power or force. Fans that don't list static pressure usually have poor SP. AF fans are most useful for exhaust, while SP fans are also important at intake positions where there is a dust filter, mesh or other barrier.  Fans for which neither AF nor SP are listed should generally be avoided. Revolutions Per Minute (RPM) is one of the top factors determining performance and noise production, so a fan with a higher max RPM will usually do better than a lesser fan. However, you may need an SP fan in an exhaust position if there is a great deal of resistance to airflow within the case.
   
   As you can see, a static pressure fan has very wide blades so that the air can't go backwards between the spaces, whereas the airflow fan has large gaps and very pitched angles to move as much air as possible without resistance.
4. **Noise Levels**: Lower decibel (dBA) levels indicate quieter operation. dBA is a modified measurement to show how your ears perceive the noise. Quieter fans can improve the overall acoustic profile of your system. If noise doesn't bother you then the only time that this should matter is when the dBA exceeds ~80 dBA constantly or repeatedly over a long period of time. https://www.nidcd.nih.gov/health/noise-induced-hearing-loss. Fans that are most likely to do this are server fans, but there are consumer fans that get that loud, too. You can compensate by placing the computer in its own space where the noise will be muffled, or by adjusting the "fan curve" to assure that it only rarely gets that loud. Also, the noise a fan makes outside of the case will be muffled by the case. Remember: just like long-term (a few hours) exposure to loud music can cause permanent hearing loss, sitting next to a VERY loud computer can, too. That's why servers have their own room.
   1. Aside from design differences, one way to reduce noise is to limit the speed of a fan using a low-noise adapter (LNA) cable. This has a resistor in the circuit to decrease the amount of electricity that the fan receives, resulting in lower RPM and, thus, less noise. Unfortunately, sometimes the most annoying noises are not created at max speed.
       
5. **Power Source**: This can be an important consideration, especially if you don't have the right PSU cables for all situations. Most commonly, fans get their power from the header on the motherboard or hub that they are connected to. However, some fans can also draw power from USB, SATA, Molex D, etc. Do NOT use more than one type of power-providing plug at the same time or you will likely cause damage. Also, make sure that your PC supports that type of power source cable.
    
6. **LED Lighting (if applicable)**: If aesthetics are important to you, consider the lighting options. Some fans come with customizable RGB lighting that can sync with your other components. Lighting on any computer part has no positive performance effects (aside from acting as an indicator) but can negatively impact performance if the fan's design hasn't been altered to increase available power so that the fan itself isn't negatively impacted in terms of performance. There are, in essence, 3 options: monochrome LEDs, variable color (RGB/chromatic) LEDs, and addressable RGB (ARGB) LEDs.
   1. Monochrome LEDs: The first only offers a single color although there can be many LEDs - each with its own color - and generally can only be on or off and are usually powered by the same cable as the fan's cable. Some fans include a toggle or selector to change the pattern, etc. These are often the least expensive fans and are most often used on DC fans, although some manufacturers pair the monochrome LEDs with PWM fans, too. Unless the design is altered, these will decrease the fan's performance.
   2. Variable color (RGB/chromatic) LEDs: The second type can change colors, patterns and frequency based on signals from software (e.g. OpenRGB, SignalRGB) or firmware (e.g. a fan/lighting hub), and have a dedicated fan cable for RGB control, and are supported by most motherboards and hubs/controllers, but are somewhat limited as to what can be achieved visually. Despite the limitations, RGB fans offer a wide degree of lighting options through hardware and software and, if the design is superior, can rival low-end ARGB fans. RGB LEDs are used on both DC and PWM fans. Some devices also provide tertiary support via a header or hub port for RGB LED strips.
   3. Addressable RGB (ARGB) LEDs: ARGB offers full control over the lighting, with the ability to individually control every fan, but not many motherboards (mobos), hubs and controllers offer the necessary support in the form of headers, ports, etc. These fans are often amongst the most expensive, and ARGB LEDs are most often found on PWM fans. A small number of devices offer tertiary support of ARGB strip lighting.
   4. No LEDs: Pretty self-explanatory, and my preference. It's a waste of money and electricity.
       
7. **Build Quality**: Build quality includes: bearing type, frame and propeller materials, airflow control, design, connector type (2-pin, 3-pin, 4-pin, Molex D, JST, proprietary) and cabling.
   1. Design: Two fans with otherwise equivalent statistics will perform differently if their designs (including materials) are different. This is probably the first or second largest contributor to performance.
      1. Frames: There are different frame designs but most are simply a square frame. Others minimize the use of plastic by having 4 anchor points that are usually rounded, although there are a few that look rather interesting, like the Alseye W12
         and the Zalman ZM-SF120.
         For radiators, the regular square frame is the best choice because it offers the least chance of leaking, especially when combined with a gasket.
      2. Blades: Fan makers have to achieve a compromise between AF and SP, and they do this with the design of the blades (length, pitch, shape, number). AF blades usually have a narrow blade and large gaps between them, while SP blades have a wide blade and a very small gap, with hybrids ranging in-between.
      3. Airflow and sound control: These design modifications attempt to direct the air, and/or reduce noise, and can look like protrusions, indentations, slots or even teeth on the fan's blades and/or frame.
         Aerocool Dead SilenceSharkoon Shark BladesXigmatek XAF-F1253Fractal Design Dynamic X2 GP-12DeepCool TF 140S
         be quiet! Light Wings
      4. Bearing type: Fans with quality bearings tend to last longer and operate more quietly. Bearing type affects price, speed, lifespan, positioning, and noise. There are many types of bearings, with rifle and sleeve bearings being of lower quality but less expensive, and ball-bearing, magnetic levitation (mag-lev) and liquid (all of which have several types with varying degrees of quality: https://silentpcreview.com/forums/viewtopic.php?t=12438) being better but more expensive. Some bearing types are more susceptible to damage by dust and/or positioning. As a fan's bearings wear out, it tends to slow down and become noisy, and this can be impacted by design and materials quality. Some bearing types only work well in the vertical position, while others work best in the horizontal position, and a few work well in both; ball-bearing, fluid dynamic bearing and mag-lev are the most versatile. A lot of factors affect the bearings, including materials in the bearings and the fan itself, stable or variable speeds, fan design, frame, mounting, heat, dust, lubrication, etc.
         1. Sleeve: inexpensive, short lifespan, starts out quiet but eventually becomes quite noisy, sudden death. You can delay its death by adding a couple of drops of synthetic oil to the axle under the sticker. ~45,000 hours if mounted horizontally. Impact resistant, dust resistant, high friction.
         2. Rifle: cheap, sleeve with rifling to help distribute the lubricant, slightly more expensive, slightly longer life, otherwise quite similar. (~50,000 hours)
         3. Ball bearing: Somewhat expensive, can be mounted in any position. Impact sensitive, dust resistant, lower friction.
            1. Single: somewhat expensive, noisier but doesn't get as loud as sleeve and rifle near the end of its lifespan; typically combines ball-bearings on one side and another, such as sleeve, on the other. Longer life than sleeve and rifle. (~60,000 hours)
            2. Double: more expensive, both ends of the shaft have ball bearings, less noise than single and longer life than single, too. (~75,000 hours)
         4. Hydro: modified sleeve with more lubrication and may have other technology. Longer lifespan than the previous, higher price, dust sensitive, low friction.
            1. Hydrostatic: a pump maintains constant lubricant pressure, ensuring that the bearing is always well-lubricated, making these last a long time and can be mounted vertically and horizontally.
            2. Hydrodynamic: the lubricant is contained and requires time to heat up and disperse so the best of this type employ secondary bearings for start/stop. Otherwise similar to hydrostatic. Some will leak when placed horizontally with the fan blowing up.
               1. Hydrowave: improved hydro bearing, less friction and longer life (~90,000), but may leak, dust sensitive, low friction.
               2. Fluid Dynamic (FDB): longer lasting (~>100,000 hours), doesn't leak, not dust sensitive, lower friction.
               3. SSO/SSO2: These Noctua bearings combine sleeve, fluid and mag-lev for superior performance, much less noise, friction and heat, resulting in long lifespan (~>300,000 hours). Amongst the best.
         5. Magnetic-levitation (mag-lev/ML): These rely primarily on magnetism to prevent the parts from rubbing and, along with SSO are amongst the quietest and very long life (~>200,000 hours), and include omniCool from CUI Systems and Mag-Lev from Corsair.
         6. "Long-life bearing": This means nothing, not even longevity, as it is used by marketing to trick people. It could be any type of bearing.
      5. Materials: Look for fans with durable materials. Liquid Crystal Polymer (LCP), for example, is one of the best materials because it doesn't easily change shape due to speed and temperature. Frame materials include not just the frame itself but any softer dampening materials at connection points to reduce vibration transmission to the PC. Virtually all vans used to be made from only metal but nowadays most fans are plastic, which decreases weight and, thus, can increase lifespan, but makes them more prone to physical damage in transit and in your computer. I've received a few with broken blades, a disconnected hub, or frame damage.
      6. Connector and cabling type: Addressed below.
   2. **Silicone Gaskets**: A few fans come with these but most don't. They are placed between the fan and whatever it's against to reduce leaking air (lost airflow/pressure). You can buy them from the fan's manufacturer or separately, although some frame designs make it quite difficult, if not impossible, to use. They can also add a splash of color.
       
8. **PWM (4-pin) vs DC (2- or 3-pin)**: 
   1. 2-pin DC: Voltage-controlled. If you need only a single-speed fan running constantly at max, and don't care what that speed is, then a 2-pin DC fan is sufficient. These are the cheapest but also the least common nowadays.
      1. Molex D: These are a Molex design that are shaped like a D and have 4 pins/holes in them, usually designed so that you can plug another into the other end of the plug. There are Molex D plug fans that are misleadingly sold as 2-4 pin when they most often use only 2 pins. If you have a Molex D fan, you can connect it directly to your PSU for consistent RPM, or get an adapter to the regular 2-pin type so it can run from the mobo or hub. Some will offer both a Molex D and a 3- or 4-pin plug. The main advantage to Molex D, aside from direct power, is that they can be daisy-chained. Although many PSU makers still provide Molex D power cables, I'm unaware of any modern mobos that do, so make sure there's also a 3- or 4-pin plug on the fan's cable!
   2. 3-pin DC: Voltage-controlled. If knowing and changing the speed of the fan is important, the 3rd pin provides a tachometer signal, which can help mobos with voltage control for speed variance. These are a bit more expensive than 2-pin fans and still fairly common.
   3. 4-pin PWM: Pulse Width Modulation (PWM) fans offer the 4th pin for direct control of the speed by "pulsing" the electricity to maintain a specific speed. How refined that control is, however, depends on the components used in the controller (e.g. mobo, hub or controller). Cheaper quality means a reduced range of control at the low end. These are generally more expensive. They are also DC fans. Some hubs and controllers claim to be PWM but only have 3 pins and, thus aren't really PWM. Some manufacturers will lie and try to convince you their products are PWM but if the 4th wire is missing, they are not. Others will label a Molex D plug as 4-pin, even if it only has 2 holes in use.
      1. Zero RPM: Some PWM fans offer "zero RPM" wherein the fan will stop spinning to save electricity when the temperature is low enough. This can be adjusted with the fan curve in BIOS or software.
   4. Proprietary connectors: Some companies, such as Corsair, Asiahorse and Lian Li, have moved towards using proprietary connectors to force customers to stick with them. Personally, I do not like this and, unless you are willing to replace the plugs and not use their hubs, you should avoid such products despite the advantages some may offer unless you plan to pay the extra cost of only buying their brand, which can sometimes be large. Proprietary connectors may have 5 or more pins/holes and you'll have to have a hub, connector, repeater or node with the same connector to use these fans. Generally, if you buy a single fan with a proprietary connector, it won't come with a hub, but a multi-pack will. JST connectors are one type that you're liable to see being used.
      Top: Corsair proprietary ARGB connector; Bottom: standard ARGB connector
      Akyga proprietary plug for PWM and LEDs
9. **Ease of Installation**: There is generally very little difference from one fan to another as to how easy it is to install, although a small number possess additional pieces that make it harder to install, and some offer multiple extra pieces so that you can more easily install them in a case, on a CPU cooler or on a radiator. For convenience, you can pay extra to get one with additional parts, some of which you may never use. Most fans simply offer short bolts or self-tapping bolts, although some will have rubber or silicone "pins" that can hold the fan in place and some will reduce vibrations traveling from the fan to the case/heatsink/radiator. However, those made of regular rubber tend to not stand up well to repeated installations because they either stretch and snap or become harder as they age. The single largest contributor to ease of installation is the size of the fan, especially thickness, so be careful to make sure that the fans won't clash with nearby parts. A small number of fans offer special installation features, such as daisy-chaining through cables or through plug-and-socket direct connects, such as Lian Li, Phanteks, SAMA and Asiahorse.
   1. Mounting Orientation: Do not confuse this with the direction of airflow. Vertical means it is "standing" and horizontal that it is "lying down".
   2. Adjustable-Direction Mounting: This is an extremely rare feature in which the frame is designed so that you can adjust the direction of airflow on 2or 3 axes. The only fan I'm aware of that offers this is the Inwin Mars 120mm Fan; it's over $60 and I cannot find it in the USA. You'll be better off 3D-printing or or buying something if you need to customize the direction of flow.
   3. Daisy-chaining: This feature reduces the tangle of cables in your case by providing one of several ways to connect in series fans that are close enough to each other by providing both a plug and a port. The first fan in the series is controlled by the header, and all fans connected to it will run at the same percentage so it's best to connect fans that are the same for consistent results. Other fans offer direct connections, effectively making them one unit when connected.
      
      SAMA 3 IN 1 ARGB PC Case Fans Uni Fan Kit Easy Link
      Asiahorse MATRIX-PINK 58 All-in-One Square FramePhanteks PH-F120D30_DRGB_PWM_BK01_3PLian Li UNI Fan SL120 V2
10. **Compatibility**: Ensure that the fan size, including thickness, fits your case and that the connectors are compatible with your motherboard. Note that although some 2-pin fan plugs cannot be attached to 3- and 4-pin headers because of a difference in pin size, you can always attach 3- and 4-pin plugs to 3- and 4-pin headers. Just keep in mind that a difference between plug and header means that the PWM feature is unavailable. Proprietary designs ensure a lack of compatibility with competing brands and, thus, should be avoided.
11. **Price**: The vast majority of fans cost less than $30, and there are many that cost less than $10, but a small number of fans cost over $100 each and are generally not worth the cost, except for special function fans that can even go into the thousands of dollars. Most fans are produced in China and Chinese companies are undermining foreign companies by offering quality fans at lower prices with good warranties, even going so far as to steal the designs from other companies that manufacture in China.
12. **Included hardware**: Fans come with anywhere from nothing, not even the "tail" or wires that go from the fan to the header plug, to screws, LNA cables, extension cables, splitter cables, toggle switches for LEDs or speed, adapters, anti-vibration corner rubbers, radiator bolts and gaskets.
13. **Warranties & Service Guarantees**: Not every company offers a warranty or service guarantee. Some companies will still help you replace a defective or broken fan, while others will give you a limited timeframe, and some won't even respond (sometimes even famous brands don't respond). Some companies don't bother to check if you're the original purchaser but others, especially more expensive brands like Noctua, may require proof-of-purchase to avoid replacing a fan that was bought used. On the other hand, Noctua also offers warranties that are longer than most other manufacturers. Additionally, the quality of support and service, both by the agents and the technicians, varies. I ordered a new Alseye fan but it came in a ripped box, so I asked for a replacement but the vendor sent another one in a different ripped box. Other companies have been much better.
14. **Direction of flow**: Most fans will have some kind of indicator on the frame showing which way the fan blows, and which way it turns. This isn't strictly necessary since you can look at the fan blades to determine both of these, but the indicators reduce confusion. You don't want to use fans with opposing directions of rotation in a push-pull configuration as they'll cancel each other out.
    1. Reversed Fan: Although this is mostly an aesthetic choice, there are "reverse" fans where they blow in the opposite direction of most fans. This is because some people want to mount it in a position where the decorative hub sticker won't be visible with a "normal" fan. There are fans that can be toggled to run in either direction although I haven't found any yet.
15. **Multiple Fans in a Row**: There are two main possibilities:
    1. Stacked: Two or more fans connected directly to each other. Unless they are exactly the same and perfectly synchronized, it is unlikely that this will result in any benefits. Given how difficult it is to achieve good results, it's not recommended.
    2. Push-Pull: This is most often done on a heatsink or radiator, where you have one or more fans on each side. For example, a 240mm radiator would have 2 fans next to each other on one side pulling in air, and another pair on the other side exhausting that air. Depending on the fans and a lot of variables, you will see an improvement over fans only on one side, but it certainly will not be even 50% better.
16. **Software**: There are a lot of different companies offering software to control fans and their lights. I don't recommend Asus Armoury Crate as it tends to take full control over the fans and doesn't like to let go (or be uninstalled). Every program has its own strengths and weaknesses. One free option is Fan Control by RemOo. Programs cannot force the hardware to do what its components won't allow, such as starting a fan below it's natural RPM minimum or the range supported by a fan hub. Software to control the LEDs was mentioned previously.
17. **Other Aesthetics**: Lighting, coloration, frame appearance and unique designs can add appeal to your setup.
    1. Cable sleeves: Since exposed wires have multiple colors that displease some people, you might want to look for fans with, or buy, cable sleeves. These will generally be woven plastic sleeves of a single color.  They also offer a modest amount of protection.
    2. Silicone gaskets and corner anti-vibration rubber pieces: If you're looking for extra color, some companies and fan makers offer these to spice up the visual appeal of the fans without wasting money on powering LEDs. Some manufacturers include them as the default, while others will include different choices for you to attach. Some companies, like Noctua, also sell silicone corner pieces and gaskets of various colors.JJHXSM Fan Damper Silicone Corner PiecesAlphacool Susurro Anti-Noise Gasket 24685Noctua NA-IS1-12 Sx2
    3. Fan colors: Many fan makers lack creativity and so you'll see a lot of fans with black, white and/or gray. Noctua's two-tone brown is an exception. Nevertheless, the increasing demand for other colors (and pure black *yawn*) have caused some companies to experiment with colors for the frames and blades. Some, such as Sharkoon, Enermax, Alseye, and Aerocool have come up with some pretty interesting looks.
    4. More lights: Some manufacturers have now taken to including embedding LED lighting in the frames. This can be especially appealing for some. Also, the number of LEDs in a fan can play an important role in the appeal, as can zoning, position and concealment.
    5. Rings, grills and other decorations: Some companies offer colored objects such as rings that can be inserted into the fan to add trim color, and there are other types of decorations, including grills, magnetic pieces and more! If you can think of it, someone's probably already made it!
18. **Reviews**: Although there are a lot of amateur and customer reviews out there, your best bet is to also look at professional reviews where they actually test fans. Although it is true that some reviewers make reviews that have been paid for by manufacturers to ensure a very positive review, if you look at a variety of different sources you should be able to get a fair idea of some things, but it's very hard to find lifespan test results. Some fans, especially from relatively unknown brands, are unlikely to have such reviews, however.
19. **Reputation**: It can be helpful to look at the reputation of a brand or product line, although sometimes there are things that you won't know about a company unless you look at watchdog organizations like the Better Business Bureau and TrustPilot, for example. Some companies will build their reputation and then take advantage of it to rip off customers, with Gateway Computers being a prominent example.

Ultimately, you have to decide what your priorities are. Personally, performance is my main concern because that is what fans are for - to cool your PC, along with price and warranty, and noise is far behind those as I've trained myself not to be bothered by noise unless it's really loud. Of course, I do look at reviews, too. Remember that, in general, when you prioritize quietness you are sacrificing performance, although notable exceptions, like the Noctua NF-A12x25 and the be quiet! Silent Wings Pro 4 high-speed fans provide great performance with less noise...but a higher price.

Don't worry - there are lots of inexpensive fans if that is what you can afford!

 

One final note: just because you've got a lot of spaces to mount fans doesn't mean you need fans there. Sometimes, adding an extra fan can actually make things worse, so be sure to check the temperatures before and after any changes to find out the best configuration.

[thrasher_565]

fan cable is also import end and ones that can daisy chain.

sleaving too but i think most have black cables or sleaving these days.

i guess and option to add accent colors to it like rubber corners.

 

i guess the argb/rgb the amount of leds it has and how many zones it has too can be noted.

 

all i can think of atm

 

i dont no if you added it or not but fans that can do zero rpm.

Edited September 15, 2023 by thrasher_565

[RevGAM]

5 minutes ago, thrasher_565 said:

fan cable is also import end and ones that can daisy chain.

sleaving too but i think most have black cables or sleaving these days.

i guess and option to add accent colors to it like rubber corners.

 

i guess the argb/rgb the amount of leds it has and how many zones it has too can be noted.

 

all i can think of atm

 

i dont no if you added it or not but fans that can do zero rpm.

Thanks! Great!

What do you mean by:
 

5 minutes ago, thrasher_565 said:

fan cable is also import end

 

Edited September 15, 2023 by RevGAM
Added question for Thrasher

[thrasher_565]

maybe square vs rounded looking fans sqare would be better on rads i would think. and there some fans that dont fit on rads...becuse it has parts fast the 120mm/140mm...

guess fans that have rubber on them vs not

rubber screws well was a good idea at the time 99% dont use em. most fans dont come with them anymore. noctura do thow.

 

good info on grills

good info on fan spacing

video about ex stream presher

Edited September 15, 2023 by thrasher_565

[Agall]

Airflow and static pressure are usually a compromise, since the blade designs are different between them. Airflow prioritized fans will generally have a higher pitch to the fan blades versus a static pressure fan that'll usually try to have lower pitch, therefore more coverage of the fan's frontal surface area. The example below being a perfect demonstration of when static pressure is needed, similar to fans mounted on radiators versus your front intake fans with no radiators.

 

The specific quality being how much space the blade's don't take up of the frontal surface area, since higher airflow would be achieved by the steeper pitch of the blade. Something you can achieve by simply having thicker fans, if the depth isn't a limitation.

 

Something I'll mention as a practical application of fan design that happened recently. I modified the cabinet of a piece of equipment we have at work to add intake+exhaust 120mm fans. The lower cabinet has old VME style circuitry, its own internal AC bus and a computer from 2002 that would appear to overheat, something we tested by having the panels open which hasn't caused the system to crash once since.

 

The cabinet is entirely sealed, minus a fan I added by modifying the compartment the PC sits in. I recently added an intake and another exhaust fan (the computer sits in a higher compartment but takes suction from the lower cabinet, which mind you is entirely sealed), being cheap Corsair/Coolermaster case fans I had laying around.

 

The problem being that the bottom of the barrel Corsair case fan I had exhausting was struggling to move any air with the panel closed. Opening the panel caused the airflow to increase by 5x or so. With my knowledge on fan design, I grabbed one of my Noctua PPC 2000RPM fans from home and tried that. Turns out it was a static pressure issue, since the air its receiving has quite the journey from the intake I added.

[RevGAM]

36 minutes ago, thrasher_565 said:

i guess the argb/rgb the amount of leds it has and how many zones it has too can be noted.

Please explain zones.

[thrasher_565]

15 minutes ago, RevGAM said:

Please explain zones.

well there leds in the hub

leds in the in side

leds on the out side

leds on the back

then there fans like the thermaltake quad riig that have 4 rings in the front... each ring can be controlled independent

 

[Somerandomtechyboi]

35 minutes ago, Agall said:

The specific quality being how much space the blade's don't take up of the frontal surface area, since higher airflow would be achieved by the steeper pitch of the blade. Something you can achieve by simply having thicker fans, if the depth isn't a limitation.

No wonder why my 3800rpm ish 12cm server fan when i run it at 5v still flows a decent chunk of air, i mean i guess its like 3.5-4cm thick but hey high performance fan for dirt cheap (overpaid for this one tho, usually theyre 1-2$)

[Agall]

2 hours ago, Somerandomtechyboi said:

No wonder why my 3800rpm ish 12cm server fan when i run it at 5v still flows a decent chunk of air, i mean i guess its like 3.5-4cm thick but hey high performance fan for dirt cheap (overpaid for this one tho, usually theyre 1-2$)

Partly what makes the Fractal Design Torrent so absurd with its thiccc 180mm front fans. You don't have to compromise as much between static pressure and airflow if you can make the fan physically thicker.

[RevGAM]

6 hours ago, Agall said:

Airflow and static pressure are usually a compromise, since the blade designs are different between them. Airflow prioritized fans will generally have a higher pitch to the fan blades versus a static pressure fan that'll usually try to have lower pitch, therefore more coverage of the fan's frontal surface area. The example below being a perfect demonstration of when static pressure is needed, similar to fans mounted on radiators versus your front intake fans with no radiators.

 

The specific quality being how much space the blade's don't take up of the frontal surface area, since higher airflow would be achieved by the steeper pitch of the blade. Something you can achieve by simply having thicker fans, if the depth isn't a limitation.

 

Something I'll mention as a practical application of fan design that happened recently. I modified the cabinet of a piece of equipment we have at work to add intake+exhaust 120mm fans. The lower cabinet has old VME style circuitry, its own internal AC bus and a computer from 2002 that would appear to overheat, something we tested by having the panels open which hasn't caused the system to crash once since.

 

The cabinet is entirely sealed, minus a fan I added by modifying the compartment the PC sits in. I recently added an intake and another exhaust fan (the computer sits in a higher compartment but takes suction from the lower cabinet, which mind you is entirely sealed), being cheap Corsair/Coolermaster case fans I had laying around.

 

The problem being that the bottom of the barrel Corsair case fan I had exhausting was struggling to move any air with the panel closed. Opening the panel caused the airflow to increase by 5x or so. With my knowledge on fan design, I grabbed one of my Noctua PPC 2000RPM fans from home and tried that. Turns out it was a static pressure issue, since the air its receiving has quite the journey from the intake I added.

That's a great example of SP vs AF fans, and a very interesting story - too bad there's not an accompanying visual to show why that power was needed. Where did you get the photo?

[Somerandomtechyboi]

3 hours ago, Agall said:

Partly what makes the Fractal Design Torrent so absurd with its thiccc 180mm front fans. You don't have to compromise as much between static pressure and airflow if you can make the fan physically thicker.

Oh so thats the torrents secret to having such cooling capabilities

 

Well i aint paying that much so ill just buy 1-2$ 24v server fans and run a buck boost controller or something

 

Why are pc fans only 2.5cm thick though? Seems like a pretty stupid handicap when thicker fans give much better performance and that front case space isnt even being used that much anyways aside from super long gpus

[freeagent]

I like 38mm fans. I used to run t hem all the time. There is no replacement for displacement. Airflow orientated fans make no sense to me.. a fan should be able to push hard and move air. I was using a stack of 120x38 Panaflos for about 15 years. Better than just about every fan made for a pc at the time. Thermalright TY-143 was a bit stronger than what I was running. I would be more impressed with the Torrents fans if they could rev to 2000 instead of 1200 lol..

 

Now you have fans like the T30 that showed up, and they are a nice fan.. I bought a triple pack. Quiet too. But not as strong as my 120x38s.

 

I should stuff them all into my Torrent and see how it does.. I have 6 of them.. hmm.

[RevGAM]

7 hours ago, thrasher_565 said:

good info on grills

good info on fan spacing

Good info!

[RevGAM]

I have updated the info and added some images, @Agall, @thrasher_565, @freeagent, @Somerandomtechyboi.

[thrasher_565]

then there were 55mm thic fans...

 

Edited September 16, 2023 by thrasher_565

[RevGAM]

@thrasher_565@Agall@TeraSeraph

I'd like to add more about bearings, but I feel uncertain, especially since there are MANY different types within some categories, especially hydro. I'll sketch out what I think I know (LOL) and hopefully I can get some input.
CUI Devices: Fan Bearing Types – Weighing the Pros and Cons

Titan Rig: Water Cooling Components - Fans
Vertical vs. horizontal - what bearings work when?
Gamers Nexus: The Basics of Case Fan Bearings - Which Bearing is Best?

 

Of course, these are generalizations and there is variability due to factors like design, materials quality, lubricant, temperature, mounting position, dust, etc. MTBF @25C.

 

Sleeve

Sleeve: cheapest, when new it's quiet but gets noisier over time, short lifespan (40g hours?),  suitable for challenging environments but prone to friction degradation, vertical mount, gases can coalesce and gum up the bearing.

High operating Temperature and Long life Sleeve (HTLS): more durable and slightly longer lifespan (50g)

Rifle: a sleeve with rifling that promotes oil distribution and so the lifespan is much better (50g?)

Fluid

Pivot: Average price, fairly quiet, decent lifespan (?), susceptible to dust entering and lubricant leaking

HydroWave: Somewhat expensive, quiet, excellent lifespan (350g?), sealed to prevent dust entering and lubricant leaking

Fluid Dynamic Bearing (FDB): improved HydroWave, expensive, quiet, of the "hydro" fans, these are the best and work well in any mounting position, excellent lifespan (>1m?), sealed

 

Ball bearing: Expensive, can be noisy and may "tick" as it ages, usually works well in any mounting position, fairly long life (75g?), suitable for high temperatures, some susceptible to dust and impacts, often used in industrial applications, dual ball bearing with more springs is better than single and less springs.

 

Magnetic Levitation (Mag-Lev Expensive, quiet, works well in any mounting position, very little friction, long life (200g?), not susceptible to dust and friction degradation, magnets maintain the position, such as Corsair ML series fans, Noctua SSO2 bearings, and CUI omniCool "-V" fans, and can last a long time, especially at lower temperatures (250g?).

Long-life: This means nothing because it can be any bearing type.

Edited September 16, 2023 by RevGAM

[thrasher_565]

52 minutes ago, RevGAM said:

@thrasher_565@Agall@TeraSeraph

I'd like to add more about bearings, but I feel uncertain, especially since there are MANY different types within some categories, especially hydro. I'll sketch out what I think I know (LOL) and hopefully I can get some input.
CUI Devices: Fan Bearing Types – Weighing the Pros and Cons

Titan Rig: Water Cooling Components - Fans
Vertical vs. horizontal - what bearings work when?
Gamers Nexus: The Basics of Case Fan Bearings - Which Bearing is Best?

 

Of course, these are generalizations and there is variability due to factors like design, materials quality, lubricant, temperature, mounting position, dust, etc. MTBF @25C.

 

Sleeve

Sleeve: cheapest, when new it's quiet but gets noisier over time, short lifespan (40g hours?),  suitable for challenging environments but prone to friction degradation, vertical mount, gases can coalesce and gum up the bearing.

High operating Temperature and Long life Sleeve (HTLS): more durable and slightly longer lifespan (50g)

Rifle: a sleeve with rifling that promotes oil distribution and so the lifespan is much better (50g?)

Fluid

Pivot: Average price, fairly quiet, decent lifespan (?), susceptible to dust entering and lubricant leaking

HydroWave: Somewhat expensive, quiet, excellent lifespan (350g?), sealed to prevent dust entering and lubricant leaking

Fluid Dynamic Bearing (FDB): improved HydroWave, expensive, quiet, of the "hydro" fans, these are the best and work well in any mounting position, excellent lifespan (>1m?), sealed

 

Ball bearing: Expensive, can be noisy and may "tick" as it ages, usually works well in any mounting position, fairly long life (75g?), suitable for high temperatures, some susceptible to dust and impacts, often used in industrial applications, dual ball bearing with more springs is better than single and less springs.

 

Magnetic Levitation (Mag-Lev Expensive, quiet, works well in any mounting position, very little friction, long life (200g?), not susceptible to dust and friction degradation, magnets maintain the position, such as Corsair ML series fans, Noctua SSO2 bearings, and CUI omniCool "-V" fans, and can last a long time, especially at lower temperatures (250g?).

Long-life: This means nothing because it can be any bearing type.

ya i dont no much about bearings just glad i dont have the crap ones that would leak and you have to put oil in them every like 2 moths...

i have some "300,000" hour fans that be quiet clames...

but most are between like 30,000 and 50,000 and like 100,00 for good ones. but i would look at warranty first. looks like 6 years is the best.

that one improvement that most fans last long enough.

 

[RevGAM]

13 minutes ago, thrasher_565 said:

ya i dont no much about bearings just glad i dont have the crap ones that would leak and you have to put oil in them every like 2 moths...

i have some "300,000" hour fans that be quiet clames...

but most are between like 30,000 and 50,000 and like 100,00 for good ones. but i would look at warranty first. looks like 6 years is the best.

that one improvement that most fans last long enough.

 

Ok. What's a good program to monitor sound levels? I've got a mic in my box connected to my line in on my mobo rather than using my phone to measure dBA.

[thrasher_565]

18 minutes ago, RevGAM said:

Ok. What's a good program to monitor sound levels? I've got a mic in my box connected to my line in on my mobo rather than using my phone to measure dBA.

no idea...

[RevGAM]

5 hours ago, thrasher_565 said:

no idea...

That's ok. Turns out the mic is dead.

[NorKris]

First post has become the definition on   "Waaaay too long didnt read"  

even so much strang pics the site lags or glithes 

[RevGAM]

1 hour ago, NorKris said:

First post has become the definition on   "Waaaay too long didnt read"  

even so much strang pics the site lags or glithes 

That's just you, Kris.

[Agall]

On 9/15/2023 at 4:35 PM, Somerandomtechyboi said:

Oh so thats the torrents secret to having such cooling capabilities

 

Well i aint paying that much so ill just buy 1-2$ 24v server fans and run a buck boost controller or something

 

Why are pc fans only 2.5cm thick though? Seems like a pretty stupid handicap when thicker fans give much better performance and that front case space isnt even being used that much anyways aside from super long gpus

Really the 'secret' to the Torrent is just massive positive pressure, to the point where if you don't properly tune those from 180mm fans especially on the compact version, it'll dead head the GPU fans. I personally think the design could use work, since the power supply is forced to suck in a lot of that heat and can cause power supply overheating issues (ran into that myself).

 

I imagine there's diminishing returns, something that scales up well to 180mm but doesn't scale down as well to 120mm, without compromise. Those 180mm fans are purpose built, where you're unlikely to find another case where those actually fit natively to reuse them.

 

Thiccccc 40mm fans in servers don't care too much for acoustics or how much air it moves at a mid range speeds, as an example. There's also a market drive for having the best fan in a given form factor, like a standard thickness 120mm/140mm fan. Exceeding that may be beneficial for some customers, but that doesn't mean its profitable or mass marketable. 

[thrasher_565]

1 hour ago, Agall said:

Really the 'secret' to the Torrent is just massive positive pressure, to the point where if you don't properly tune those from 180mm fans especially on the compact version, it'll dead head the GPU fans. I personally think the design could use work, since the power supply is forced to suck in a lot of that heat and can cause power supply overheating issues (ran into that myself).

 

I imagine there's diminishing returns, something that scales up well to 180mm but doesn't scale down as well to 120mm, without compromise. Those 180mm fans are purpose built, where you're unlikely to find another case where those actually fit natively to reuse them.

 

Thiccccc 40mm fans in servers don't care too much for acoustics or how much air it moves at a mid range speeds, as an example. There's also a market drive for having the best fan in a given form factor, like a standard thickness 120mm/140mm fan. Exceeding that may be beneficial for some customers, but that doesn't mean its profitable or mass marketable. 

i also think servers have changed from when we thing of them in a 1u rack. now there like min itx, long and they do one thing. one dose just ram, one dose just cpu, one dose just gpu, i also belave they dont use 120mm fans anymore and probly just ac the room or use bigger cheaper 48v fans. or water cooling.

the servers that do use that old stuff is well old used stuff i would think. i could be wrong thow.

 

think of it like an asic miner .

 

[Agall]

2 hours ago, thrasher_565 said:

i also think servers have changed from when we thing of them in a 1u rack. now there like min itx, long and they do one thing. one dose just ram, one dose just cpu, one dose just gpu, i also belave they dont use 120mm fans anymore and probly just ac the room or use bigger cheaper 48v fans. or water cooling.

the servers that do use that old stuff is well old used stuff i would think. i could be wrong thow.

 

think of it like an asic miner .

 

There are standard commercial and datacenter variations, which I imagine datacenters are outside of the scope of this conversation. I imagine some places having such enormous scale that they have custom solutions for thermodynamics, like what LTT has shown in some tour videos.

 

I can speak on behalf of standard commercial servers, especially Dell's products since I manage several dozen, some being as old as DDR3 systems. One I have as a spare/test machine on my desk, an R530, having 50mm thick fans that appear to be 40mm in diameter. The space these machines occupy being enclosed for security and has its own HVAC unit.

 

My previous network having dedicated sealed compartments with its own HVAC supply, but the servers themselves were a custom solution, although air cooled. The severs themselves had no fans and had a blade style design, where the rack/cabinet handled cooling entirely.