Question Which size is quieter 120mm or 140mm fan?

[Harry_Wild]

Looking into buying a 5 pack of Arctic (p or f)12 (120mm) or 14 (140mm) fans to use to cool a tower computer case inside and need to know which size is more quieter give the same heat temperature conditions inside the case.

I think p is 4 pin and f is 3 pins?

Thanks!

 

[Tech Junky]

I use the pst pwm versions of both and they're silent as far as I can tell.

 

[Fallen Kell]

All thing similar, 140mm fans will move more air at lower RPMs (and thus lower noise) than 120mm fans. This is due to the area of the spinning fan blades in 140mm fans are roughly 36% larger.

 

[Tech Junky]

p is 4 pin and f is 3 pins

Also, using PWM is better for quiet as they adjust to cool as needed rather than the DC versions that run at a constant speed.



I have a total of 8 fans running off these headers including the 2 on the CPU. The CPU fans are the 120's and the rest are 140's.

Using the PWM PST versions allow to keep the wiring clean as well since they piggy back off each other instead of needing their own header to connect.

In a more compact machine I was running 12 total fans and kept everything cool and silent.

 

[Harry_Wild]

All thing similar, 140mm fans will move more air at lower RPMs (and thus lower noise) than 120mm fans. This is due to the area of the spinning fan blades in 140mm fans are roughly 36% larger.

Thanks! Did not read your wise reply until now! I will switch from 120 to 140mm. I usually do forums while watching TV!🤪

 

[mindless1]

There seems to be some info missing. What is "cool a tower computer case inside"? Where exactly are these fans being used?

If they are mounted on the case wall for case intake or exhaust, you don't want a 120mm fan on a 140mm fan mount, with open case holes all around the outside of the frame, creating a short loop where it sucks the air right back in (or out, depending on fan orientation).

On the other hand if you have a 120mm fan mount, and put a 140mm fan there, you may gain as much or more noise from turbulence than you might have otherwise lost from lower RPM to achieve same airflow rate.

Further, there is also the situation where if your interior fans like CPU or more likely video card, make audible noise, it can cause more noise to escape the case to have larger, and especially more case panel mounted fans than needed, instead of using material to block off the unneeded fan openings, particularly on the front, or side panel if on a desk facing the user.

 

[BoomerD]

There seems to be some info missing. What is "cool a tower computer case inside"? Where exactly are these fans being used?

If they are mounted on the case wall for case intake or exhaust, you don't want a 120mm fan on a 140mm fan mount, with open case holes all around the outside of the frame, creating a short loop where it sucks the air right back in (or out, depending on fan orientation).

On the other hand if you have a 120mm fan mount, and put a 140mm fan there, you may gain as much or more noise from turbulence than you might have otherwise lost from lower RPM to achieve same airflow rate.

Further, there is also the situation where if your interior fans like CPU or more likely video card, make audible noise, it can cause more noise to escape the case to have larger, and especially more case panel mounted fans than needed, instead of using material to block off the unneeded fan openings, particularly on the front, or side panel if on a desk facing the user.

Exactly. Get the fan size the case was meant to have. SOME will have mounts for 120/140, but MOST will be made for one size or the other.

 

[aigomorla]

140mm are quieter at the same rated CFM. but that only applies when comparing like with like.
With larger blades the motor has to do more work due to more mass it needs to spin.
Most motors were not optimized for the added weight so for the longest time 120mm fans even tho they were smaller would outperform 140mm variants in things like static pressure, due to a better optimization of motor and blade geometry.

You can't just slap a larger blade geometry and expect it to perform the same. Its like lets put larger blades on a jet turbine and see if it will go faster.

But 140mm fans have evolved a lot though out the years. I would most definitely use them for applications like a exhaust fan, or intake fans.
I would also use Noctua fans which come with Noctua heatsinks for 140mm class, as Noctua has pretty much optimized the blade geometry for it.
I would not use some unknown amazon 140mm fan which claims it can move air like a typhoon at the noise of a fly.

In general, for heatsinks, and radiators, i'll always stick with 120mm, as its just way more matured, and motors for them have been optimized for so long, even the guys who copy the fan tend to copy the motor design and blade geometry.

For exhaust, or intake, i'll be OK, with a 140mm, in almost any variant, as they will be quieter, and move more air because of the larger surface area.
For 140mm heatsinks, i'll only use a premium fan like a eK Vadar, or Noctua, as they have pretty much hashed out what needs to be changed on the larger size.

For 200mm fan, well, your in the wild wild west, so i would also try to stay with a reputable vendor that is known not to fudge numbers.

 

[Fallen Kell]

For 200mm fan, well, your in the wild wild west, so i would also try to stay with a reputable vendor that is known not to fudge numbers.

I don't think such a vendor exists that doesn't fudge some of the numbers. As you stated, I trust Noctua for most of their technical numbers, but their marketing pages are just that, marketing pages and I don't trust those as far as I can throw the digital ones and zeros that make them up.

Unfortunately fan tests/reviews are something that have seemed to have gone to the wayside as they are time consuming to do correctly with limited payoff for such an endeavor. About the only places that fans are tested anymore are as part of a heatsink/AIO/radiator. Silent PC Review (and even Anandtech) used to do some extensive reviews on these components, but as I stated, it is very time consuming to do correctly. The closest I have seen recently are the various benchmarks on 3D printed custom fan assemblies/blades on various youtube videos. This loss of reviews and benchmarking I feel has let most of the fan manufacturers get away with way too much marketing speak in their fan's performance information (I think the only things I really trust anymore are the physical dimensions and the power ratings/draw). Everything else is so subjective on the method used to determine the value as well as the testing environment, conditions, and approaches that the values are almost all completely useless to compare fans.

 

[Harry_Wild]

I got my In Win 904+ case but have not unbox it yet! Waiting for after Thanksgiving to do so! Buy fans for sure! Going by the ones with white lights on the rim to light up my clear side panel. 2 140mm lite fans that are extra quiet running.

 

[BoomerD]

I don't think such a vendor exists that doesn't fudge some of the numbers. As you stated, I trust Noctua for most of their technical numbers, but their marketing pages are just that, marketing pages and I don't trust those as far as I can throw the digital ones and zeros that make them up.

Unfortunately fan tests/reviews are something that have seemed to have gone to the wayside as they are time consuming to do correctly with limited payoff for such an endeavor. About the only places that fans are tested anymore are as part of a heatsink/AIO/radiator. Silent PC Review (and even Anandtech) used to do some extensive reviews on these components, but as I stated, it is very time consuming to do correctly. The closest I have seen recently are the various benchmarks on 3D printed custom fan assemblies/blades on various youtube videos. This loss of reviews and benchmarking I feel has let most of the fan manufacturers get away with way too much marketing speak in their fan's performance information (I think the only things I really trust anymore are the physical dimensions and the power ratings/draw). Everything else is so subjective on the method used to determine the value as well as the testing environment, conditions, and approaches that the values are almost all completely useless to compare fans.

I don't know if they have it operational yet or not, but Steve @ Gamer's Nexus has been talking about a new fan testing device/machine.