Best exhaust fan?

Peat Moss

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Just wondering if there is a fan design that is more optimally suited to exhausting air rather than pushing air? Kind of like the opposite of static pressure?
 

pendragon1

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Just wondering if there is a fan design that is more optimally suited to exhausting air rather than pushing air? Kind of like the opposite of static pressure?
"air flow" fans are the "opposite", usually theres AF vs SP in the product name
 

doubletake

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Assuming same/similar hub sizes, airflow-oriented fans will generally have more but narrower blades, while pressure-oriented ones will have fewer but wider blades. Use that as a visual reference when you're sorting through fans for a specific purpose if you don't want to have to parse through all the marketing terms and jargon. After that, make sure to look up some reviews to see if they will in fact be suitable for your intended task.
 

Peat Moss

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I'm assuming a good exhaust fan would work on the same principle as a good intake fan, since they both need to be good at sucking air in and pushing it out the back?
 

doubletake

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Not really, because exhaust fans generally aren't fighting to move air through/past anything (case exhausts specifically, not talking about pull fans on sinks/rads). Case intake fans need to have decent pressure so that they can pull air through filters/mesh/etc (unless you run an unfiltered or an open case), which is something exhausts don't have to do, so they don't have to have particularly great pressure performance, just mass airflow capability.
 

somebrains

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You don't need a Delta or a Sunon in a consumer case unless it's stupid restrictive with lots of 90deg turns.

Simply adding a top mounted exhaust forward of your cpu cooler will negatively affect cooler performance.

Heat pooling spots may benefit from addition of a fan that isn't your exhaust.

Lower chamber components like psu and gpu may start to intake from whatever cracks intake air can find entry or thru your pcie slot covers.

I'd argue that not blocking your gpu/psu area with a stupid long gpu, and just trying 1 rearmost top mounted exhaust if air cooling, would be a worthwhile experiment vs +1 power to your existing exhaust fan.
 

pitingres

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Just wondering if there is a fan design that is more optimally suited to exhausting air rather than pushing air? Kind of like the opposite of static pressure?
A fan doesn't know whether it's pushing air into a volume or pulling it out. A fan just creates a pressure differential; in conjunction with any existing pressure difference, such as one created by an intake fan, the differential results in airflow. Some fans are better suited to moving the most air across a small differential, that's an "airflow" or free flow fan. Some are better at dealing with larger differentials without stalling, that's the static pressure fan.
 

Rev. Night

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I have a Noctua Sf-12 and it does the job perfectly. It's basically at 50-60% PWM on the entire time and its dead silent. Intakes are 2-3 Arctic P12s.
 

Nobu

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Generally, if there is no restriction, you can more or less trust the CFM rating of the fan (at full speed, with the usual disclaimers). The higher the static pressure, the less any restriction there IS, will effect air flow through the fan.

That said, some designs will have high static pressure, but lack airflow capability at mid-low rpm, or will be loud at high rpm. You need to look at all the specs and decide what balance works for you. Pick a few, and look at the reviews for those fans.
 

Peat Moss

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Some fans, like the Noiseblocker NB eLoop create channels of air, whereas others spread the air out more. I wonder if that is the difference between static pressure and air flow fans, and whether either is more suited to being an exhaust fan?
 

pendragon1

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Some fans, like the Noiseblocker NB eLoop create channels of air, whereas others spread the air out more. I wonder if that is the difference between static pressure and air flow fans, and whether either is more suited to being an exhaust fan?
yes and yes, depending on the case. if its exhaust spot has a lot of material to move through a sp is best, if its wide open af is best. sp helps move the air through restrictions, af moves more air.
 

doyll

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What pitingres said is pretty much what it is. But some fans can pull better than others. All my builds use push, so can't really help with what fans to use.

Just curious, why do you want to setup case pulling air through rather than pushing air through? I experimented for years and didn't find any advantage to pulling air through cases, but did find advantages to pushing air through. Pushing helps keep dust out and stops dust from leaking in thorough all openings, like USB sockets, audio sockets, etc.
 
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