Static pressure or airflow fans?

[WoodenMarker]

2 minutes ago, wzrd said:

But I will humour you, here is the link you asked for. https://en.wikipedia.org/wiki/Drag_equation

I call something outside of a margin for error. Scientifically, 5% is considered a fair margin for error in statistical analysis. 2/54 = 3.7%, which would be inside the margin for error of a study done using lab-grade equipment in a lab environment, which this reddit study is not. That said, I can see how you would consider it valid, and I accept your opinion as fair, though I disagree with it.

Results are only as accurate as the way they were measured. Handheld anemometers are not accurate, as I explained before. Calculations are always accurate and have virtually zero margin for error.

Your wiki link only mentions the density of the fluid and not the body. Do you see how I think you're mistaking the two?

54c and 52c isn't 3.7% difference until you decide the reference point. As far as I'm concerned, 2c difference if shown consistently, is often what differentiates a Dark Rock 3 from a Dark Rock Pro 3 for example. Even if you consider it within margin of error, it shouldn't be ignored if it's consistent with different tests.

Calculations are only accurate until they don't reflect things in reality. I don't have an aversion to math.

My main point is that the density of the body doesn't really matter--show me something that says otherwise. If it's such a basic principle, it should be easy to point me to it.

[wzrd]

Just now, WoodenMarker said:

Your wiki link only mentions the density of the fluid and not the body. Do you see how I think you're mistaking the two?

54c and 52c isn't 3.7% difference until you decide the reference point. As far as I'm concerned, 2c difference if shown consistently, is often what differentiates a Dark Rock 3 from a Dark Rock Pro 3 for example. Even if you consider it within margin of error, it shouldn't be ignored if it's consistent with different tests.

Calculations are only accurate until they don't reflect things in reality. I don't have an aversion to math.

My main point is that the density of the body doesn't really matter--show me something that says otherwise. If it's such a basic principle, it should be easy to point me to it.

I used the reference point he provided, i.e. the change over idle  That is definitely a fair point. There are many others too - for example, you could argue that in the case of multiple fans, this would make far more difference. I disagree, but that doesn't mean your opinion isn't valid. There is a difference between test validity and reliability. 

 

It hasn't been tested in reality in a controlled environment. I think we can both agree that the tests done by Puget and on forums don't constitute a controlled environment?

 

My mistake, wrong equation. I understand your point. I did incorporate the density of the air. I used a specific modulus regression to account for rigidity. In this calculation, I used the density of the fan material relative to the density of the air. More details here: https://en.wikipedia.org/wiki/Specific_modulus. The principle is that of moment arms and flex, and you would probably be more likely to find consolidated info on it in a mechanics or even biomechanics textbook.

[WoodenMarker]

1 minute ago, wzrd said:

It hasn't been tested in reality in a controlled environment. I think we can both agree that the tests done by Puget and on forums don't constitute a controlled environment?

 

My mistake, wrong equation. I understand your point. I did incorporate the density of the air. I used a specific modulus regression to account for rigidity. In this calculation, I used the density of the fan material relative to the density of the air. More details here: https://en.wikipedia.org/wiki/Specific_modulus. The principle is that of moment arms and flex, and you would probably be more likely to find consolidated info on it in a mechanics or even biomechanics textbook.

They're controlled to some extent. If you think that their results are due to errors, link results that show otherwise. It's somewhat common knowledge that air filters can greatly decrease airflow.

Here are some less controlled examples that demonstrate similar results.

https://forums.overclockers.co.uk/threads/dust-filter-raising-temps.18712383/

https://hardforum.com/threads/do-you-use-fan-dust-filters.1652856/

http://www.hardwarecanucks.com/forum/water-cooling/65976-prodigy-m-dust-filter-inceasing-temps-15-a.html

Most people don't have very expensive hardware to pinpoint the difference a dust filter makes but the change in temps is generally obvious and you can try it yourself.

 

I don't see how specific modulus has anything to do with airflow or air resistance. Sure, it may play a part in fan design and how the fan behaves but that's beside the point.

[wzrd]

Just now, WoodenMarker said:

They're controlled to some extent. If you think that their results are due to errors, link results that show otherwise. It's somewhat common knowledge that air filters can greatly decrease airflow.

Here are some less controlled examples that demonstrate similar results.

https://forums.overclockers.co.uk/threads/dust-filter-raising-temps.18712383/

https://hardforum.com/threads/do-you-use-fan-dust-filters.1652856/

http://www.hardwarecanucks.com/forum/water-cooling/65976-prodigy-m-dust-filter-inceasing-temps-15-a.html

Most people don't have very expensive hardware to pinpoint the difference a dust filter makes but the change in temps is generally obvious and you can try it yourself.

My calculations do not disagree with that point, at all. They conclude that:

• Air filters do not provide a significant amount of air resistance and so do not require static-pressure optimised fans to overcome.
• Air filters reduce airflow by approximately 10% per fan, according to the numbers provided by Puget, using an AF140 fan as an example. This may very depending on the static pressure rating of the fan, its CFM, etc., but can be used as a general guideline.
• In a perfect thermal situation (i.e. most efficient heatsink possible), heat dissipation rate was reduced by about 10% in a single fan situation, which did not provide a significant difference in net temperature dissipation (about 0.32C difference) in the example values used. While it is likely that the thermal efficiency of the heatsink would be worse, a real case situation would have many more fans at play, and the combined effect across all of these fans could lead to a more significant effect on actual component temperatures.

My point was never that they don't have any thermal implications, only that they don't have significant thermal implications, but what you consider significant is up to you. I was simply arguing my point of view.

 

The only one of my points I see as not debatable is the use of static pressure fans in any situation except on radiators; it's simply not justified. That said, brand, build quality, fin design and mounting design of fans are way larger factors in fan performance than whether it is static pressure or air flow optimised. The differences between air flow and static pressure fans are minimal in terms of actual airflow performance in a closed environment anyway, as everything is restricted by the fact that they are mounted to a case.

 

I think that is a good point on which to leave it. You can interpret the results of these calculations whatever way you wish, and you will find plenty of contradictions to my opinions above provided by @WoodenMarker. 

32 minutes ago, WoodenMarker said:

I don't see how specific modulus has anything to do with airflow or air resistance. Sure, it may play a part in fan design and how the fan behaves but that's beside the point.

It doesn't, but it is used to calculate rigidity. I used a modulus regression to calculate rigidity, then used that to calculate equivalent air density relative to the grill fan material for maximum accuracy, before applying a drag coefficient, and using it to calculate air resistance. The actual difference is very very very very minimal, I just did it for the sake of being as accurate as possible, it would make little difference in reality. To put it in perspective, density of air at STP is 1.225kg/m³. Relative density was calculated by me to be approximately 1.2236614kg/m³, so if it makes you happier to neglect density as a factor and use the standard number, then feel free, change should be minimal.

[WoodenMarker]

1 minute ago, wzrd said:

My calculations do not disagree with that point, at all. They conclude that:

• Air filters do not provide a significant amount of air resistance and so do not require static-pressure optimised fans to overcome.
• Air filters reduce airflow by approximately 10% per fan, according to the numbers provided by Puget, using an AF140 fan as an example. This may very depending on the static pressure rating of the fan, its CFM, etc., but can be used as a general guideline.
• In a perfect thermal situation (i.e. most efficient heatsink possible), heat dissipation rate was reduced by about 10% in a single fan situation, which did not provide a significant difference in net temperature dissipation (about 0.32C difference) in the example values used. While it is likely that the thermal efficiency of the heatsink would be worse, a real case situation would have many more fans at play, and the combined effect across all of these fans could lead to a more significant effect on actual component temperatures.

The only one of my points I see as not debatable is the use of static pressure fans in any situation except on radiators; it's simply not justified. That said, brand, build quality, fin design and mounting design of fans are way larger factors in fan performance than whether it is static pressure or air flow optimised. The differences between air flow and static pressure fans are minimal in terms of actual airflow performance in a closed environment anyway, as everything is restricted by the fact that they are mounted to a case.

The number for air resistance being small doesn't matter. Performance is noticeably decreased and that's big enough for most people to consider significant.

Puget didn't test filters. They simply said that one of the grills can work as a rudimentary filter. The test demonstrates that even open grills that are less restrictiveness than air filters can make a measurable difference in performance.

The example values you used didn't match the results from Reddit while are rather significant since the filter was at the front of the case as opposed to the front of the cpu fan. This is significant because a fan on a heatsink will usually make a bigger difference in temps than a fan at the front of the case.

 

Your aversion to static pressure fans is arbitrary because what's considered a static pressure fan is arbitrary.

[wzrd]

1 minute ago, WoodenMarker said:

The number for air resistance being small doesn't matter. Performance is noticeably decreased and that's big enough for most people to consider significant.

Puget didn't test filters. They simply said that one of the grills can work as a rudimentary filter. The test demonstrates that even open grills that are less restrictiveness than air filters can make a measurable difference in performance.

The example values you used didn't match the results from Reddit while are rather significant since the filter was at the front of the case as opposed to the front of the cpu fan. This is significant because a fan on a heatsink will usually make a bigger difference in temps than a fan at the front of the case.

It does not in terms of performance, but it is meaningful in the context of people buying optimised fans, and actually ending up with less air flow as a consequence, because they're using static pressure fans where they should be using air flow.

 

While this is all true, even the scenario you describe only describes a 1-2C difference. Even if we assume the tests are accurate, which is a very big if - temperature changes that small could even be caused by things like fluctuation in ambient, or even fluctuations in power delivery - it is still a tiny difference in performance compared to other factors, that can effect temps by literally ten times more. My point being, to me, 1C is a small price to pay for reducing dust build up by a huge amount.

 

18 minutes ago, WoodenMarker said:

Your aversion to static pressure fans is arbitrary because what's considered a static pressure fan is arbitrary.

This is completely fair. I don't have an aversion to them, but I don't believe they should be used in any situation other than on radiators, or where the obstruction is within the suction radius of the fan, which is no more than 2cm, but varies between brands. 

 

I would, however, love to see a standard for the optimisation being built in, because as you pointed out, what is considered a static pressure fan varies significantly from brand to brand.

[WoodenMarker]

1 minute ago, wzrd said:

It does not in terms of performance, but it is meaningful in the context of people buying optimised fans, and actually ending up with less air flow as a consequence, because they're using static pressure fans where they should be using air flow.

 

While this is all true, even the scenario you describe only describes a 1-2C difference. Even if we assume the tests are accurate, which is a very big if - temperature changes that small could even be caused by things like fluctuation in ambient, or even fluctuations in power delivery - it is still a tiny difference in performance compared to other factors, that can effect temps by literally ten times more. My point being, to me, 1C is a small price to pay for reducing dust build up by a huge amount.

 

I would, however, love to see a standard for the optimisation being built in, because as you pointed out, what is considered a static pressure fan varies significantly from brand to brand.

If not airflow, how would you define performance?

The tests are consistent across the board. I believe they're accurate enough.

Other factors are independent of the performance of case fans unless the ambient temp is higher than the temp of components. Better performance means better performance.

1-2c is relatively significant in a well cooled system like the one tested. In cases where airflow is suboptimal, the difference dust filters make is much larger. There's plenty of anecdotal evidence showing people with high temps seeing a dramatic improvement when removing dust filters.

 

What's high or low static pressure is relative to other fans and how much static pressure is optimal on average changes with other components. The NF-P12 for example was labelled a static pressure fan until noctua released heatsinks with denser fin arrays and the NF-F12. It's now considered a balanced fan airing on the side of static pressure. Having a fan labelled airflow/static pressure is great for marketing though--look at Corsair.

[wzrd]

Just now, WoodenMarker said:

If not airflow, how would you define performance?

The tests are consistent across the board. I believe they're accurate enough.

Other factors are independent of the performance of case fans unless the ambient temp is higher than the temp of components. Better performance means better performance.

1-2c is relatively significant in a well cooled system like the one tested. In cases where airflow is suboptimal, the difference dust filters make is much larger. There's plenty of anecdotal evidence showing people with high temps seeing a dramatic improvement when removing dust filters.

I would define, performance as performance of the overall system. At the end of the day, a 1-2C rise in temperatures across a system is not going to affect how the system actually performs. This is exactly my point - if your system has a well balanced cooling solution, it shouldn't require the extra 1-2C drop to be gained by removing the filters. If it is so hot that it requires removing the filters, it probably has bigger problems  

 

I would also question as to whether the reason they have these high temps in the first place is because they have a problem with dust build-up? Dust-clogged filters would definitely limit performance significantly more. As some of my other calculations demonstrated, the material spread across the filter has a huge effect on air resistance, and even a moderate amount of dust could make the resistance far more marked.

 

5 minutes ago, WoodenMarker said:

What's high or low static pressure is relative to other fans and how much static pressure is optimal on average changes with other components. The NF-P12 for example was labelled a static pressure fan until noctua released heatsinks with denser fin arrays and the NF-F12. It's now considered a balanced fan airing on the side of static pressure. Having a fan labelled airflow/static pressure is great for marketing though--look at Corsair.

I'm going to confess that my knowledge of specific fans and brands, and even the spec differences between airflow and static pressure fans is non-existant; my conclusions are based off the assumption that the increased static pressure reduces airflow, which is counterproductive when a filter is used, but I don't know the specifics of brands.

 

As a side note, I would be interested to hear your opinion of EK-Vardar fans in comparison to other brands?

[WoodenMarker]

Just now, wzrd said:

I would define, performance as performance of the overall system. At the end of the day, a 1-2C rise in temperatures across a system is not going to affect how the system actually performs. This is exactly my point - if your system has a well balanced cooling solution, it shouldn't require the extra 1-2C drop to be gained by removing the filters. If it is so hot that it requires removing the filters, it probably has bigger problems  

 

I would also question as to whether the reason they have these high temps in the first place is because they have a problem with dust build-up? Dust-clogged filters would definitely limit performance significantly more. As some of my other calculations demonstrated, the material spread across the filter has a huge effect on air resistance, and even a moderate amount of dust could make the resistance far more marked.

 

I'm going to confess that my knowledge of specific fans and brands, and even the spec differences between airflow and static pressure fans is non-existant; my conclusions are based off the assumption that the increased static pressure reduces airflow, which is counterproductive when a filter is used, but I don't know the specifics of brands.

 

As a side note, I would be interested to hear your opinion of EK-Vardar fans in comparison to other brands?

So you're saying case fans don't matter in a discussion about case fans.

Improvement in temps are generally dramatic with or without dust build up when removing filters. You can try it yourself to see.

Vardars are a pretty close copy to Gentle Typhoons. They perform well and are relatively quiet. Depending on who you ask, GT's sound better or Vardars do. I personally find GT's a bit quieter but hearing is a bit subjective.

[wzrd]

7 minutes ago, WoodenMarker said:

So you're saying case fans don't matter in a discussion about case fans.

Improvement in temps are generally dramatic with or without dust build up when removing filters. You can try it yourself to see.

Vardars are a pretty close copy to Gentle Typhoons. They perform well and are relatively quiet. Depending on who you ask, GT's sound better or Vardars do. I personally find GT's a bit quieter but hearing is a bit subjective.

No, I'm saying that whether or not the fans are filtered is probably not going to be a significant factor in how your system performs as a whole.

 

I don't define the 1-2C you already referred to as drastic. Has this changed in the mean time?

 

interesting, cheers!

[WoodenMarker]

Just now, wzrd said:

No, I'm saying that whether or not the fans are filtered is probably not going to be a significant factor in how your system performs as a whole.

I don't define the 1-2C you already referred to as drastic. Has this changed in the mean time?

interesting, cheers!

1-2c in a system with good cooling translates into a bigger difference in a system with worse cooling because the first system is already experiencing diminishing returns. 

It's why there are threads about people seeing >5c drop in temps when their temps aren't already <60c at load.

Temps never affect performance when they're already good enough. It's with oc'ing or inadequate cooling that the extra bit of cooling pulls the most weight.

What has changed? --not sure what you mean.

[wzrd]

3 minutes ago, WoodenMarker said:

1-2c in a system with good cooling translates into a bigger difference in a system with worse cooling because the first system is already experiencing diminishing returns. 

It's why there are threads about people seeing >5c drop in temps when their temps aren't already <60c at load.

Temps never affect performance when they're already good enough. It's with oc'ing or inadequate cooling that the extra bit of cooling pulls the most weight.

What has changed? --not sure what you mean.

This is a fair premise. But while I am willing to (reluctantly) accept your data on the already adequately cooled PCs in semi-controlled environments. Random anecdotal accounts do not constitute evidence in my books I'm afraid. There are innumerable other factors that could have caused this drop.

 

1-2C is not going to effect even the highest overclocks. You also have to consider limiting factors, i.e. bottlenecks. It is almost universally true that there will be a weaker link in the chain at those temps than fan filters, like heat transfer from die to IHS, IHS to cold plate, cold plate to fluid (in the case of water cooling, for example), or cold plate to heatsink (air cooling), etc., so the 1-2C difference of dust filters is not going to be the limiting factor, one of those will.

 

I thought we already agreed that temp changes were not "drastic"?

[WoodenMarker]

Just now, wzrd said:

This is a fair premise. But while I am willing to (reluctantly) accept your data on the already adequately cooled PCs in semi-controlled environments. Random anecdotal accounts do not constitute evidence in my books I'm afraid. There are innumerable other factors that could have caused this drop.

 

1-2C is not going to effect even the highest overclocks. You also have to consider limiting factors, i.e. bottlenecks. It is almost universally true that there will be a weaker link in the chain at those temps than fan filters, like heat transfer from die to IHS, IHS to cold plate, cold plate to fluid (in the case of water cooling, for example), or cold plate to heatsink (air cooling), etc., so the 1-2C difference of dust filters is not going to be the limiting factor, one of those will.

 

I thought we already agreed that temp changes were not "drastic"?

Sure, it's fine to doubt anecdotal evidence. If you haven't already, I'd suggest trying it yourself though since the change in temps is usually relatively quick and the factor being changed is obviously the dust filter.

1-2c isn't drastic but the difference between 52c and 54c bigger than the difference between 90c and 92c. I'd say an improvement of 2c when under 60c is pretty significant.

If you're heavily oc'ing, the difference would be more than 2c. There's a reason why the difference in temps when testing coolers widen with oc'ed tests compared to stock.

The better the transfer of heat from die to ihs, other factors/etc, the less significant having more case airflow would make due to diminishing returns. Case airflow is the last in the chain, so to speak. The more these other factors raise temps, the bigger difference the case fans make.

[wzrd]

1 minute ago, WoodenMarker said:

Sure, it's fine to doubt anecdotal evidence. If you haven't already, I'd suggest trying it yourself though since the change in temps is usually relatively quick and the factor being changed is obviously the dust filter.

1-2c isn't drastic but the difference between 52c and 54c bigger than the difference between 90c and 92c. I'd say an improvement of 2c when under 60c is pretty significant.

If you're heavily oc'ing, the difference would be more than 2c. There's a reason why the difference in temps when testing coolers widen with oc'ed tests compared to stock.

The better the transfer of heat from die to ihs, other factors/etc, the less significant having more case airflow would make due to diminishing returns. Case airflow is the last in the chain, so to speak. The more these other factors raise temps, the bigger difference the case fans make.

I have, and I experienced absolutely no change. But I accept this is likely due to the fact that the PC I tried it on is water cooled and already running at less than 5C above ambient while idle

 

That largely comes down to perspective, but I wouldn't consider 2C significant in any of my own builds, which would always run far below 60C. The weather in Ireland causes fluctuations in ambient, and consequently operating, temps of far more than 2C.

 

This is exactly my point. Chances are that components aren't sensitive enough to changes in case airflow for the performance impact to be noticeable.

[WoodenMarker]

Just now, wzrd said:

I have, and I experienced absolutely no change. But I accept this is likely due to the fact that the PC I tried it on is water cooled and already running at less than 5C above ambient while idle

That largely comes down to perspective, but I wouldn't consider 2C significant in any of my own builds, which would always run far below 60C. The weather in Ireland causes fluctuations in ambient, and consequently operating, temps of far more than 2C.

This is exactly my point. Chances are that components aren't sensitive enough to changes in case airflow for the performance impact to be noticeable.

They are plenty sensitive enough if temps aren't very low already. You should be testing at load and not idle. Lowering temps by even 1c if your temps are only 5c above ambient is very significant. Think about how much cooling it would take to achieve that.

[wzrd]

4 minutes ago, WoodenMarker said:

They are plenty sensitive enough if temps aren't very low already. You should be testing at load and not idle. Lowering temps by even 1c if your temps are only 5c above ambient is very significant. Think about how much cooling it would take to achieve that.

There was no change at load either. I only gave the difference from ambient at idle as an illustration of how cool it runs. I even turned the fans up to max to get the biggest difference in air flow possible.

 

I'm not saying this is usual though. It is a modded 760T, which has good airflow anyway, with 13 fans and two 60mm triple rads, so it's not a fair illustration of the average system.

 

I'm not denying that it's a significant cooling change, I'm just disputing that it is a significant performance change.

[WoodenMarker]

1 minute ago, wzrd said:

I'm not denying that it's a significant cooling change, I'm just disputing that it is a significant performance change.

Cooling performance is what I'm talking about. Cooling is irrelevant to system performance as long as its adequate.

[wzrd]

Just now, WoodenMarker said:

Cooling performance is what I'm talking about. Cooling is irrelevant to system performance as long as its adequate.

Then we might finally be in agreement?

 

My point is that dust filters probably do effect temperatures slightly, but not to a degree significant enough to effect system performance, and so in my opinion have more benefits than drawbacks.

 

My other point is how this thread started, and is that there is zero point buying static pressure optimised fans to overcome an average dust filter, at least where Corsair fans are concerned, though I would suspect this is the case for most brands. I would assume you can shed more light on how Corsair's take on static pressure vs airflow compares to other brands, though?

[WoodenMarker]

5 minutes ago, wzrd said:

My point is that dust filters probably do effect temperatures slightly, but not to a degree significant enough to effect system performance, and so in my opinion have more benefits than drawbacks.

 

My other point is how this thread started, and is that there is zero point buying static pressure optimised fans to overcome an average dust filter, at least where Corsair fans are concerned, though I would suspect this is the case for most brands. I would assume you can shed more light on how Corsair's take on static pressure vs airflow compares to other brands, though?

Dust filters are great but should be taken into consideration when choosing a fan to put next to it.

All fans are technically static pressure optimized. You're getting hung on technicalities. 

Corsair's SP and AF labels are great marketing and doesn't change the product. They shouldn't be isolated in a bubble and I see them as part of a spectrum of many fans with different balances of SP/AF. Labeling a pair of fans as AF/SP isn't actually that helpful. 

Their AF120's are pretty nice and versatile. They're decent for many heatsinks with loose to slightly dense fin arrays. SP120's are pretty useless if you care about acoustics. They only shine on rads or if you want performance through a dense heatsink without regard for acoustics. Even then, there are slightly better/louder options.

AF140's are kind of irrelevant.They're good in very open cases. SP140's only come in led if not SP140L's and are significantly worse than the ringed models. When it comes to led variants, AF140/SP140 are very similar but the SP140 has more static pressure and is a bit louder.

[wzrd]

Just now, WoodenMarker said:

Dust filters are great but should be taken into consideration when choosing a fan to put next to it.

All fans are technically static pressure optimized. You're getting hung on technicalities. 

Corsair's SP and AF labels are great marketing and doesn't change the product. They shouldn't be isolated in a bubble and I see them as part of a spectrum of many fans with different balances of SP/AF. Labeling a pair of fans as AF/SP isn't actually that helpful. 

I'm not, I have no illusions as to how small the degree of difference is. The concept that people buy fans specifically to overcome minuscule amounts of resistance is flawed, is my point.

 

I'm not, I just picked them as examples of popular fans, and for consistency as the only difference between them is their optimisation, so it minimised the number of variables. My question is, where do they fall on the spectrum of balances compared to other fans, in your opinion?

[WoodenMarker]

Just now, wzrd said:

I'm not, I have no illusions as to how small the degree of difference is. The concept that people buy fans specifically to overcome minuscule amounts of resistance is flawed, is my point.

I'm not, I just picked them as examples of popular fans, and for consistency as the only difference between them is their optimisation, so it minimised the number of variables. My question is, where do they fall on the spectrum of balances compared to other fans, in your opinion?

Was editing my post on opinion on some of Corsair's AF/SP line.

It comes back to what you think is a minuscule amount of resistance and what is more static pressure than necessary. If it's not arbitrary, give an example of where the static pressure of the SP140 would be helpful and one where it wouldn't over the AF140. 

When it comes to coming up with an answer to that, you're probably going to have to make an educated guess, right? I'm using my experience with the S340 and similar fans in it.

I don't see many 140mm fans that have less static pressure relative to airflow than the AF140. Most manufacturers seem to overcompensate on that area to make up for the thickness of the fan not scaling up compared to a 120mm. The closest I can think of is probably the HF14 which seems to be more or less a similar balance. As for SP140's, they're just a bit more than most stock case fans like the FN V2's from NZXT or SSR2's from Fractal Design. They're not nearly as heavily oriented to static pressure as NF-A14's or Vardars for example.

Just educated guesses.

[wzrd]

2 minutes ago, WoodenMarker said:

It comes back to what you think is a minuscule amount of resistance and what is more static pressure than necessary. If it's not arbitrary, give an example of where the static pressure of the SP140 would be helpful and one where it wouldn't over the AF140. 

When it comes to coming up with an answer to that, you're probably going to have to make an educated guess, right? I'm using my experience with the S340 and similar fans in it.

Yes and no. Mathematically, we would have to define the optimal amount of net static pressure for a case fan after accounting for resistance, i.e. the net static pressure after subtracting the resistance provided by radiator, dust filter, etc., i.e. how much the static pressure rating of a fan needs to be for optimal airflow in an unrestricted setting. This would require testing in a controlled environment to define with any degree of accuracy. Once we had this value, we could calculate the value of a given resistance, using calculations like the ones I provided, and add that to the minimum unrestricted value necessary, to determine the minimum static pressure rating the fan must have to provide optimal air flow, while accounting for the resistance. This is the only way to get an exact value in Pa for optimal static pressure ratings. For the purposes of calculations, I just did them relative between the AF140 and SP140, but for a truly accurate prediction of exactly how much static pressure is necessary, we would need to first find the optimal amount without any resistance.

 

Is it just me or are the Corsair LED fans crazily loud? I have a massive box of them I have no intention of ever using

 

[WoodenMarker]

1 minute ago, wzrd said:

Yes and no. Mathematically, we would have to define the optimal amount of net static pressure for a case fan after accounting for resistance, i.e. the net static pressure after subtracting the resistance provided by radiator, dust filter, etc., i.e. how much the static pressure rating of a fan needs to be for optimal airflow in an unrestricted setting. This would require testing in a controlled environment to define with any degree of accuracy. Once we had this value, we could calculate the value of a given resistance, using calculations like the ones I provided, and add that to the minimum unrestricted value necessary, to determine the minimum static pressure rating the fan must have to provide optimal air flow, while accounting for the resistance. This is the only way to get an exact value in Pa for optimal static pressure ratings. For the purposes of calculations, I just did them relative between the AF140 and SP140, but for a truly accurate prediction of exactly how much static pressure is necessary, we would need to first find the optimal amount without any resistance.

Is it just me or are the Corsair LED fans crazily loud? I have a massive box of them I have no intention of ever using

Yeah, what I meant is that it's impractical to actually test every scenario and it's more realistic to make an educated guess. Just about everything can be calculated if you have the time.

Corsair LED fans are far from quiet for sure. They're significantly worse than the ringed counterparts if you didn't know.