FEATURED Positive case pressure vs Negative case pressure

[Bobnova]

Noise level wise it's on par with an average vacuum cleaner, but higher pitched.
Sadly those aren't sold in the US, but a similar Delta model is, they're $30-$45 bucks generally.

 

[OCMusicJunkie]

Well, I'm working out the logistics on wiring the start button, keyboard and DVI cable from my bench rig on the storage shelf out in the garage through to room next to it... that way it can be as loud as it likes, and also will be nice and chilly at night. Maybe I'll wait until that project is finished before I decide to get a fan that is comparable to a vacuum cleaner.

 

[ivanlabrie]

I know a guy who can get us some JouJyes...posted that in the benching team lounge.
So hurry up and join the team

 

[OCMusicJunkie]

I know a guy who can get us some JouJyes...

Why does this sound like we're druggies and not computer geeks?

I'm just waiting to hit the 100 post-count now- already flew way past the required 20 points on HWBot! Unless you can sneak me in early, I guess I better stop benching and reply to more threads.....

 

[ivanlabrie]

Why does this sound like we're druggies and not computer geeks?

I'm just waiting to hit the 100 post-count now- already flew way past the required 20 points on HWBot! Unless you can sneak me in early, I guess I better stop benching and reply to more threads.....

lol

Good idea...I had way more posts than boints when I first joined, so that's a good way to start

Them JJ fans are awesome, and the onboard pwm splitter is magnificent.
I couldn't wait for them and ordered two Nidec 220cfm pwm 4pin beasts, but I've yet to use the pwm feature or test them on my Silver Arrow cause I lack a proper pwm splitter (and now a cpu).
Those were 9usd + 6usd shipping at fleabay.

 

[OCMusicJunkie]

Man do I need to get some proper gear to go around my components. I'm still using >$40 cases and run all Rosewill RFX-120 fans at the moment ($4.99 each baby!). The airflow is impressive compared to anything else for the price, especially with 2-ball bearings and not just sleeve, but I'm assuming there is a reason most people spend more than a five-spot on their fans.

 

[ivanlabrie]

Man do I need to get some proper gear to go around my components. I'm still using >$40 cases and run all Rosewill RFX-120 fans at the moment ($4.99 each baby!). The airflow is impressive compared to anything else for the price, especially with 2-ball bearings and not just sleeve, but I'm assuming there is a reason most people spend more than a five-spot on their fans.

People tend to buy solely based on bling and Corsair factor...so don't base yourself on that.
Those fans are actually pretty neat, there're a few fan review/testing threads at OCN and here. Those are good reference for what fans perform like, in real life. Manufacturer specs tend to be shady, and bearing types false...
Rosewill does make good fans too, like these.

 

[OCMusicJunkie]

Those Hyperborea 120's are actually what I am planning on switching to for my HTPC setup. It's hard to find PWM fans that are claimed to spin that slow/quiet. My Logisys 120's are nice, but too loud at 1300rpm full speed and only use a 3-pin connector.

 

[ivanlabrie]

Gelid silent wing pwm, arctic f12 pwm CO, cougar hdb pwm, zalman zmsf3 ( http://www.legitreviews.com/article/1485/1/ )

 

[Bobnova]

The Noctua F12F-12-FFF121212121F or whatever the hell it is will spin at around 125rpm via PWM. Pretty impressive. I reviewed it here: http://www.funkykit.com/component/c.../8569-review-noctua-nf-f12-pwm-120mm-fan.html

 

[OCMusicJunkie]

Thanks for the tips you guys. Either of you have any opinon on which of those models is as close to silent as you could get for a 120mm front intake and matching rear exhaust? I don't need to move a ton of air- it's only cooling a 95w Athlon X3 and a 6670 with a big passive heatsink attached. Noctua has always been the company I presume to be the quietest, but considering how little airflow I need (easily <42cfm my logisys rates at), maybe there are better options...

I keep thinking about going 100% fanless, but I assume that passive heatsinks assume there is going to be air circulation from some other source. Passive PSU/CPU/GPU and no case fans probably wouldn't last too long...

 

[ivanlabrie]

Thanks for the tips you guys. Either of you have any opinon on which of those models is as close to silent as you could get for a 120mm front intake and matching rear exhaust? I don't need to move a ton of air- it's only cooling a 95w Athlon X3 and a 6670 with a big passive heatsink attached. Noctua has always been the company I presume to be the quietest, but considering how little airflow I need (easily <42cfm my logisys rates at), maybe there are better options...

I keep thinking about going 100% fanless, but I assume that passive heatsinks assume there is going to be air circulation from some other source. Passive PSU/CPU/GPU and no case fans probably wouldn't last too long...

The NF-F12 pwm by Noctua is by far the quietest 120mm fan that still moves good amounts of air and has good pressure for restrictive stuff (like mesh, grills, radiators...) Kinda pricey but it's the best, currently.
I'd go with one of the cheaper alternatives I mentioned above, particularly the 9usd Gelid fans and call it a day. Zalman is a bit more expensive but quieter, specially the zm-sf3 which has good pressure ratings and airflow and is DEAD silent.

 

[doyll]

You could use something like the HR-02 with it's TY-140/147 fan, remove rear grill and duct it out back of case. Doing this will cause it to move air though the case and cool everything else with no additional noise. Less noise in room because there is more between listener and fan.

 

[Bobnova]

If there's enough mesh in the case and everything has large enough heatsinks you could do full passive.

Fan wise, I don't really know.

 

[ivanlabrie]

Ducting plays nice with the hr-02 + single fan + no grill in the back.
Filters are going to kill the airflow unless they are super good quality though, I'd probably ditch them for something like that and dust the thing regularly.

 

[Dragoon]

Ideally, one would want neutral pressure (just as much air being sucked in as there is being blown out)

I agree with this. Pressure isn't a great measurement. You don't want pressure, you want flow.
Pressurising your case, will force air out of any/all gaps and cracks.
Similarly
De-pressurings your case will have air been drawn in from random places.

You want to control the direction of the airflow so that it flows smoothly through your case and reaches the vital areas, not just churns until it finds a way out. When cooling, quantity of air is more important then its quality.

 

[doyll]

I agree with this. Pressure isn't a great measurement. You don't want pressure, you want flow.
Pressurising your case, will force air out of any/all gaps and cracks.
Similarly
De-pressurings your case will have air been drawn in from random places.

You want to control the direction of the airflow so that it flows smoothly through your case and reaches the vital areas, not just churns until it finds a way out. When cooling, quantity of air is more important then its quality.

Mostly agree.

"Air flow not air blow".

I like enough pressure that no air is being sucked in anywhere but through fans. Just keeps things cleaner.
Think quality of airflow is more important the quantity of airflow.. I think that's what you in the above sentence too.

 

[doyll]

Ducting plays nice with the hr-02 + single fan + no grill in the back.
Filters are going to kill the airflow unless they are super good quality though, I'd probably ditch them for something like that and dust the thing regularly.

Filters do restrict but to me the advantage far outweighs the disadvantage. My filters need cleaned weekly.. Takes seconds. It's part of vacuuming the room. Pop off, vacuum, back on. So much easier and faster than having to move case up onto desk, open it all up, remove cooler fans to clean fins.. and don't even want to think about cleaning GPU.

 

[OCMusicJunkie]

I still think the idea of "negative pressure" pulling in air from all openings is somewhat valid. What other purpose would there be for vents in a case that aren't designed for fan mounting? With the majority of matx cases, you'd never in a million years get the GPU cooled if you relied on direct airflow from a case fan. Having slotted PCI covers under the card with enough negative pressure to pull air through has been the only way I've gotten away with an aftermarket passive cooler.

 

[Bobnova]

Pushing air out, IMO. I use 'em for exhaust ports.