I was told side case fans whether exhaust or intake are a no-no. They disrupt the normal flow of air, correct? Or did I hear wrong? Well, I have a case that has an intake fan. I usually have an equal number of exhaust/intake (3 exhaust from the back including the PSU, and 2 intake on front, 1 intake on side in my particular scenario)...
Are side case fans really that bad?
- Thread starter Xpred
- Start date
I don't see what's so bad about blowing some cool air from outside the case onto your CPU heatsink . . .
Depends on the case. But nowadays with ubar hot video cards a side fan can make a HUGE difference. My side intake fan hits my vid card, RAM and north bridge. The 2 front intake fans have 3 HDs blocking them and the rear two exaust are high up near the CPU. So the low side intake fan complements my case well (antec 1080 AMG). So I have 3 intake and 3 exaust (counting the PSUs two exaust fans as one). Its a good balance in my setup.
- May 13, 2003
- 13,704
- 7
- 81
In most cases, the side fan is usually mounted below the video card. The video card is wide enough in most systems that any air that makes it under the video card gets stuck there, because exhaust fans are usually mounted above the video card.
In most situations, it really doesn't matter. 99% of manufactuers don't consider the flow of air through the case a superior design point. Most cases are not engineered to have optimal air flow. A fan anywhere that can expell or take in air is usually going to do more good than anything.
In most situations, it really doesn't matter. 99% of manufactuers don't consider the flow of air through the case a superior design point. Most cases are not engineered to have optimal air flow. A fan anywhere that can expell or take in air is usually going to do more good than anything.
HardWarrior
Diamond Member
- Jan 26, 2004
- 4,400
- 23
- 81
If a case is well-designed, meaning that it has the right fan cuts to foster front to back, bottom to top air flow, a side door fan MIGHT interfere with that process. However, I've had such positive results from using one that I don't really care.
My CM Staker has a side case fan. There doesn't seem to be a problem at all with it.
Maybe it does depend on the case.
Maybe it does depend on the case.
mindwreck
Golden Member
- May 25, 2003
- 1,585
- 1
- 81
They're not entirely bad. Matters where the fan hole and with fan you have on it. I used to have one on my case til i mod'd the panel and put a window. Mine was over the video card and after i took it out, the temps on it when up a ~1-2C but the noise leaking out of it was gone and i was happy about that.
You can see my system arrangement of fan and components here:
http://htpcnews.com/forums/uploads/post-6-1127599238.jpg
I've experimented with several facets of my side vent, that's adjacent to the 2 rear exhaust. All in all, the best positioning was for it to be served as an intake for my CPU (delta of 4-5C vs. exhaust / no fan @ full load). The only problem I experienced with this (or rather I presumed), was that the warm air was now hitting the Video card (in the blue PCI-E slot). I had to move it into the 2nd PCI-E slot (hence I am only at 8x). This arrangement, coinciding with my recently purchased 7800GTX NV Silencer 5, has total system temps down to the 31C range while keeping my OC CPU pretty kool 50C @ full load.
Honestly, as others as mentioned, depending on your case and fan arrangments, YMMV.
http://htpcnews.com/forums/uploads/post-6-1127599238.jpg
I've experimented with several facets of my side vent, that's adjacent to the 2 rear exhaust. All in all, the best positioning was for it to be served as an intake for my CPU (delta of 4-5C vs. exhaust / no fan @ full load). The only problem I experienced with this (or rather I presumed), was that the warm air was now hitting the Video card (in the blue PCI-E slot). I had to move it into the 2nd PCI-E slot (hence I am only at 8x). This arrangement, coinciding with my recently purchased 7800GTX NV Silencer 5, has total system temps down to the 31C range while keeping my OC CPU pretty kool 50C @ full load.
Honestly, as others as mentioned, depending on your case and fan arrangments, YMMV.
BonzaiDuck
Lifer
- Jun 30, 2004
- 16,127
- 1,741
- 126
I read through the article, and let me extend my thanks.
This is a useful article, except that it assumes one thing: air which has been "warmed" will significantly mix (through turbulence) with air which is still cooler before it is expelled from the case.
Count the heat-generating components excluding the PSU (which usually has its own fan but provides another exhaust channel for case air). They are small enough in number that a significant percentage of airflow can be "focused" in certain hot items (for instance, the CPU HSF and especially the CPU.)
The more you can focus and control air through low-volume, high-airflow passages, the more you can control what gets done with the exhaust if it has not had a change to mix with "other" case air.
The side-panel blow-hole supplementing a CPU-fan intake helps here, but it also produces more noise on a surface that is more likely to come in direct contact with user ears than fans mounted in the rear. And the sound doesn't just travel in the direction of airflow -- it travels against it -- maybe there's a Doppler effect, but it doesn't make the sound go away.
So fewer fans are better if you can control both the noise and the air they disperse -- hence motherboard ducting. True -- "more" fans of the same size and lower rpms may mean less noise and more airflow, but when you consider the area consumed by a case side-panel filled with fans, it becomes harder to direct that air. More fans means more power consumption, and also more heat.
Directed air-flow will reduce both the need for running fans at noise-producing rpms, the number of fans, and the overall noise.
I've moved away from exclusive preferences for large 120mm fans. In certain situations, for instance drive-bay cooling and motherboard-bottom ventilation, a 70 or 80mm "slim" fan (15mm thick as opposed to 25mm) -- running with a 7VDC tail instead of a 12VDC tail -- may be just the thing. They can be had as either "tip-magnetic" or "mag-lev" fans, or in less exotic designs. Some are better than others.
This is a useful article, except that it assumes one thing: air which has been "warmed" will significantly mix (through turbulence) with air which is still cooler before it is expelled from the case.
Count the heat-generating components excluding the PSU (which usually has its own fan but provides another exhaust channel for case air). They are small enough in number that a significant percentage of airflow can be "focused" in certain hot items (for instance, the CPU HSF and especially the CPU.)
The more you can focus and control air through low-volume, high-airflow passages, the more you can control what gets done with the exhaust if it has not had a change to mix with "other" case air.
The side-panel blow-hole supplementing a CPU-fan intake helps here, but it also produces more noise on a surface that is more likely to come in direct contact with user ears than fans mounted in the rear. And the sound doesn't just travel in the direction of airflow -- it travels against it -- maybe there's a Doppler effect, but it doesn't make the sound go away.
So fewer fans are better if you can control both the noise and the air they disperse -- hence motherboard ducting. True -- "more" fans of the same size and lower rpms may mean less noise and more airflow, but when you consider the area consumed by a case side-panel filled with fans, it becomes harder to direct that air. More fans means more power consumption, and also more heat.
Directed air-flow will reduce both the need for running fans at noise-producing rpms, the number of fans, and the overall noise.
I've moved away from exclusive preferences for large 120mm fans. In certain situations, for instance drive-bay cooling and motherboard-bottom ventilation, a 70 or 80mm "slim" fan (15mm thick as opposed to 25mm) -- running with a 7VDC tail instead of a 12VDC tail -- may be just the thing. They can be had as either "tip-magnetic" or "mag-lev" fans, or in less exotic designs. Some are better than others.
BonzaiDuck
Lifer
- Jun 30, 2004
- 16,127
- 1,741
- 126
Only thing i will add here is that my side fan gives me an ear bashing i'd rather not have which brings me to my question, should i have air blowing into the case or sucking air out? The fan points directly towards the CPU. When the Fan is blowing into the case its quiet, when its sucking air out it makes a racket so i know which i prefer.
P.S. i have a small fan at the rear of the case sucking air out but its not that effective as it is in a plastic box with grills in it that holds 2 fans. I reckon the fan would be far more effective if it was free from its surroundings but hey what can ya do?
P.S. i have a small fan at the rear of the case sucking air out but its not that effective as it is in a plastic box with grills in it that holds 2 fans. I reckon the fan would be far more effective if it was free from its surroundings but hey what can ya do?
JEDIYoda
Lifer
- Jul 13, 2005
- 33,986
- 3,320
- 126
I have one exhaust fan......120mm......I have one intake on the bottom front--120mm
I have one side fan....80 mm drawing air into the computer...
I have one Zalman 80 mm slim fan blowing ir on my memory as well as the dead spot...which for some reason is where my memory is..lol
Are side fans necessary.....depends on your system...
what are you trying to acheive....etc
I have one side fan....80 mm drawing air into the computer...
I have one Zalman 80 mm slim fan blowing ir on my memory as well as the dead spot...which for some reason is where my memory is..lol
Are side fans necessary.....depends on your system...
what are you trying to acheive....etc
BonzaiDuck
Lifer
- Jun 30, 2004
- 16,127
- 1,741
- 126
Here are my personal case-modding guidelines for side-panel blow-holes. Keep in mind that I now have several cases which probably need a Lexan port-hole installed where I have decided a blow-hole is no longer needed, but still there . . . .
Directed air-flow can find more than adequate air-sources from the intake fans, whether or not there is a side-panel blowhole. But a side-panel blowhole -- sucking air in -- will direct additional air to the CPU. It would be better to allow the CPU-fan to draw air from both the front-intake and the blowhole.
Since the blowhole transmits noise, try to avoid using one which sits in front of a fan with a modicum of noise or settings for high-CFMs (and air-turbulence).
If you have to use a blowhole in that situation, try to put a noise-deadening obstruction in front of the fan, with room for air to be drawn from around the obstruction to the fan intake. This suggests a larger "ventilation hole" or grille than the size of the fan would dictate. It might also marginally increase ventilation, since air is being drawn from a larger intake area.
It should be possible to stagger the location of the CPU-fan and the vent, so that direct sound waves from the fan are blocked or deadened. For instance, a case-side-panel could be modified to create a raised "scoop" opening to the case rear -- possibly even serving double-duty as a case-side-panel-handle-hole. But the scoop itself would cover the hole directly in front of the fan.
I favor using fan-screen-filters for blow-hole ducts or the fans in line with those ducts. Especially for a CPU fan, more debris and dust will clog the heatsink fins from an unfiltered blowhole than from intake fans -- filtered or unfiltered.
If the CPU-fan is to be fed by both front-intake fan-pressure and the blow-hole air-intake, then it makes sense to position the filter so that only the blow-hole air is filtered, allowing free unrestricted movement from air already filtered by the front intake fans.
As for using a side-blow-hole for exhaust: this needs to be integrated into the entire scheme of inner-case air-flow. For instance, you could duct a motherboard to exhaust air through the heatsink fins and blowhole. But avoid starving other exhaust-fan deployments -- like the PSU fan -- especially the PSU-fan.
Directed air-flow can find more than adequate air-sources from the intake fans, whether or not there is a side-panel blowhole. But a side-panel blowhole -- sucking air in -- will direct additional air to the CPU. It would be better to allow the CPU-fan to draw air from both the front-intake and the blowhole.
Since the blowhole transmits noise, try to avoid using one which sits in front of a fan with a modicum of noise or settings for high-CFMs (and air-turbulence).
If you have to use a blowhole in that situation, try to put a noise-deadening obstruction in front of the fan, with room for air to be drawn from around the obstruction to the fan intake. This suggests a larger "ventilation hole" or grille than the size of the fan would dictate. It might also marginally increase ventilation, since air is being drawn from a larger intake area.
It should be possible to stagger the location of the CPU-fan and the vent, so that direct sound waves from the fan are blocked or deadened. For instance, a case-side-panel could be modified to create a raised "scoop" opening to the case rear -- possibly even serving double-duty as a case-side-panel-handle-hole. But the scoop itself would cover the hole directly in front of the fan.
I favor using fan-screen-filters for blow-hole ducts or the fans in line with those ducts. Especially for a CPU fan, more debris and dust will clog the heatsink fins from an unfiltered blowhole than from intake fans -- filtered or unfiltered.
If the CPU-fan is to be fed by both front-intake fan-pressure and the blow-hole air-intake, then it makes sense to position the filter so that only the blow-hole air is filtered, allowing free unrestricted movement from air already filtered by the front intake fans.
As for using a side-blow-hole for exhaust: this needs to be integrated into the entire scheme of inner-case air-flow. For instance, you could duct a motherboard to exhaust air through the heatsink fins and blowhole. But avoid starving other exhaust-fan deployments -- like the PSU fan -- especially the PSU-fan.
TRENDING THREADS
-
Discussion Zen 5 Speculation (EPYC Turin and Strix Point/Granite Ridge - Ryzen 9000)- Started by DisEnchantment
- Replies: 24K
-
Discussion Intel Meteor, Arrow, Lunar & Panther Lakes Discussion Threads
- Started by Tigerick
- Replies: 20K
-
-
-
Facebook
Twitter