Noctua NH-U12F ~ Replacing fans for better cooling

[Guest Gir]

I just ordered a Noctua NH-U12F and I want to replace the fan with 2 fans in a push full configuration. I have 2 yate loon highspeed fans that do 88cfm each that i was planning on using, but now what im asking is would i see any benefit by using two panaflo fans that do 114.7cfm each?

 

I asked a few years ago about using a fan with that kind of cfm would be of any benefit and was told once you get above 80 it really doesnt matter, and if i can save $30 then great.

 

Thanks

[Guest Gir]

Does noone know the answer if i could benefit from the dual 114.7cfm fans or would the dual 88cfm fans move enough air?

[Guest Blooz1]

I doubt those Panaflos would buy you much except more noise!

[Guest Gir]

Thanks, anyone else want to voice an opinion before i order the yate fans?

[powsmowl]

id go for the 88cfms...when testing fans in my case ive had REALLY bad expierences with anything above ~95cfm

[Guest Gir]

Thanks and turns out i has 2 extra yate fans so i dont have to order anything at all. thanks again

 

 

edit* i have 3 of the yate loon high speed fans in my case now and they r suppose 2 be 40db (i have them plugged into molex with the pass through connects that came on them so the are getting 12volt) but they arent really all that load for my taste, i mean i definately know they are running but they arent a nuisance

[General Septem]

Thanks and turns out i has 2 extra yate fans so i dont have to order anything at all. thanks again

 

 

edit* i have 3 of the yate loon high speed fans in my case now and they r suppose 2 be 40db (i have them plugged into molex with the pass through connects that came on them so the are getting 12volt) but they arent really all that load for my taste, i mean i definately know they are running but they arent a nuisance

 

One thing about reviews is that some people consider anything audible to be loud, whereas some people only consider it loud if it's a nuisance.

 

There are also two types of noises. The first, and least intrusive, is broadband noise, which covers the entire audible spectrum (or most of it). Examples include waterfalls and whooshing noises. The other type is that whirring, whiny, pitched noise. This is much more obtrusive because it's a small range of frequencies standing out in volume in contrast to the rest of the audible range.

 

So 40Db broadband noise won't sound nearly as loud as 40Db of pitched noise. Silent PC Review describes it like this:

 

Pure Tones Vs. Broadband: The plucking of a guitar string was cited as an example of a pure tone. It is one that decays, unlike a held key on an electronic organ, which is also a pure tone. The undecaying steady tone is much more common in computers, with rotating devices like fans and hard drives. The sound of a waterfall or of the surf heard from a distance is broadband; it is composed of random noise in the entire audible frequency spectrum. Such broadband noise that occurs in nature can generally be described as pink noise - its loudness decreases with increasing frequency. Most machine-generated broadband noise has a flatter frequency balance, with equal loudness at high and low frequencies. This is called white noise, usually perceived as more intrusive than pink. Most human beings are more comfortable with broadband noise than with pure tones, if there is little loudness difference between them. So the "whoosh" of air blown by a fan is less intrusive than the high frequency "whine" that can emanate simultaneously from that same fan if it is small and spinning at high speed.

[Guest Gir]

2 replies i got on another forum and i thought i'd share to pass on some knowledge

 

"I am selling Noctua Heatsink in my country and according to my experience and my customer feedback, the performance increment due to higher cfm fans in Noctua U12 isnt that great. In my opinion, Noctua U12F is designed for people that need a silent setup. If you dont mind about the sound level, Thermalright Ultra 120 Extreme is a better option.

 

Besides that, using those push / pull method for air cooling is over rated in my opinion. In my own testing, I only noticed a 0.5'C - 1'C difference between single and dual fan setup. Anyway, 88cfm fan is more than enough for U12."

 

and

 

"Hi bro.

I cant personally tell you how much (physically) adding cfm affects in this heatsink.

 

Just some things to remember is that design on every heatsink is different and so thats how they can react to a different cfm, pressure.

 

Some months ago using WCing, I tried every radiator there was in the market. I just wanted to test how good they work with different fans (cfm) and what was better (Pull, push or both) and which would be the best balance.

 

As far as I know, something above 70-80cfm will not work best in your Noctua with the exception of a very little (not even noticeable) performance gain.

 

Using push/pull config is not that over-rated, since you can try using more slient or (less cfm) lower fans and have the same performance than just one with high rom, cfm (which sounds like vacum cleaner or airplane in the house).

 

I think Anything over 70-80cfm on this design will not be a noticeable gain. When fins are more tight, you can expect a performance gain because air psuhed (or pulled) trough the fins has more pressure and so this can cool it more efficiently. But when you have fins more separated, you need less air and pressure to do the work, and thus is why adding more airflow to it wont result into a noticeable gain.

 

Also, depending on design push and pull solutions will work more (or less) efficiently.

 

Hope this info will help you in your thoughts."

[rainwood]

Though this does not answer what you’d like to know,

here’s my experience in using the heatsink postein in the “DIY-Street Forums > Cases, Cooling, & Modifications Industrial Parkway > Cooling > Aircooling - What about the NOCTUA NH-U12?” thread.

And my small tests of 120mm fans in my case (#1 & #2) posted in the “DIY-Street Forums > Cases, Cooling, & Modifications Industrial Parkway > Cooling > Aircooling - Need a 120mm Fan” thread.