SIDE PANEL FAN: In or out?

[Mr_Hat]

As I'm sure many of you know, the debate on whether a side panel case fan should be for intake or exhaust is probably one that will never end. Should it be bringing cool air in from outside the case and forcing it towards the CPU and graphics card, or should it be expelling hot air from inside the case? I am determined to make the right choice in the matter so I'm asking the bright minds of Cain's Lair for your input. You can assume that there is also a front-mounted intake fan and a rear-mounted exhaust fan present.

--Mr_Hat

[51ay3r]

I use mine to bring it in down to the cpu and vid card, then my case has intakes on the top (a little strange) and exhausts on the back.

[paceman]

Well since hot air rises, I have my side fans pulling in air and the one on top blowing it out. I think it creates better air flow. But of course it's just MHO.

[PeanutButterSnake{CLR}]

"I'm no expert from recent experience (heck, I have a latop. Have not had a desktop for 6 years now), but when I did have desktops, it always seemed to me that intake fans blowind directly on the CPU and other cards work far better than simply sucking air out."

Ok, that was the typical response. Now here is the PeanutButterSnake(TM) response:

On the intake side of a fun, the air molecules come from all over the place, but especially from near the fan itself. Each molecule moves slowly as it enters the fan. There is not a lot of force on any particular molecule exerted by the fan. There is higher pressure on the air moleclues on the intake side of the fun because they are stuffed closer together. This restricts the airflow from further away. If your fan was sucking out in the side of a case for instance, the air molecules further away, at the actual components, would be hindered somewhat more from entering the fan than the close by air molecules.

BUT as the air molecules go through the fan, they speed up and receive more kinetic energ. They are moving faster obviously than they were on the intake side. The air pressure on the outtake side of the fan is therefore lower.

So, what happens if you apply these physics principles to a computer fan system?

Blowing directly on components is a Good Thing (TM) because you are forcing the molecules to actually REACH the components with their high velocity.

Sucking air from components is not as effective, because you are sucking the many air moleules that were not even recently near the components (plus, air molecules through various slits in your case).

Here is a good analogy: Take a shower. Then dry yourself using these two methods:

1) A fan blowing directly on you.
2) A fan sucking air away from your body.

Q. Which one makes you feel colder?
A. The one that passes more air molecules per second onto the body. Which is #1, a fan blowing directly on you. <there are some evaporation issues in this situation, but the conclusion is the same either way.>

P.S. I don't care whether it's on the side or top or whatever. I was only talking about DISTANCE from the components.

All other things being equal, then the closer the intake fan is to blow on the components, the better. This also assumes you have good airflow in general of course.

[Apache Warrior]

All fans suck. Except when they blow. :mutley:
Apache

[Pain_Killer{CLR}]

I have 5 case fans ,aside from the psu fans(2)
2 fans in front blowing in
1 side fan blowing in
2 exhaust fans blowing out
psu fans -out

i think there should be a positive pressure air flow,rather than a negative pressure air flow or equal

[Amwryn]

I have 5 case fans ,aside from the psu fans(2)
2 fans in front blowing in
1 side fan blowing in
2 exhaust fans blowing out
psu fans -out

i think there should be a positive pressure air flow,rather than a negative pressure air flow or equal

man... you rig... blows....

[KillerRabbit]

Though PeanutButterSnake makes some good points, one thing that also needs to be considered is what the air flow in your case is like. Personally, I have a nice current that simply goes front to back. It keeps everything at good temps, and even if I add fans, I either see no change or an increase in temps.

So, more info is needed about your setup. The side panel is rather large. Where is your fan? Below the graphics card, around the CPU, dead center? How are your other fans arranged? How many in front and back? One on top? What internal fans do you have?


Always remember, more fans != better cooling. I've known a few people with similar setups as mine and their temps are worse with their 8 case fans that with my 5 fans total.

[Slaughter]

Just open up the side of the case and duct tape a box fan to it and get it over with. 8)

[Mr_Hat]

Just open up the side of the case and duct tape a box fan to it and get it over with. 8)

LOL!

In regards to my particular setup...
12cm intake fan in the front
12cm exhaust fan on the back
9cm intake fan on the side panel (just about level with the CPU)
PSU has an intake fan on the inside, exhaust fan on the outside
Dual fans on GPU with heat pipe
Chipset fan
Standard AMD64 CPU fan
Actually, I have this: http://www.thermaltake.com/xaserCase/tsunami/swa/swa.htm

[res1492]

All fans suck. Except when they blow. :mutley:
Apache


Heheheeh.......:nerd:

[Apache Warrior]

Or run a duct to your case from a window airconditioning unit. That and a couple of exhaust fans are all you need. I have 8 fans total so my computer sucks and blows. :mutley:
Apache

[fizbanrt]

If you live in a cold-climate area, just put it outside the window.... :)

[ViTO]

It all has to do with air flow in general.
It needs to remain constant through the entire case.

Your cpu & video draw air away from the components, where does that air go ?
Do you want to push that air back to the unit which creates a bottleneck in the over-all flow.

do this.... Get someone who smokes heavy ( he he ) or a can of smoke and blow it into your case. look for dead spots where smoke sits stagnant.

Air should move in from one direction and out from another that could be any direction depending on case design, cabling, components, etc...

There is no set standard to how it SHOULD be.

[Nomadicus]

do this.... Get someone who smokes heavy ( he he ) or a can of smoke and blow it into your case. look for dead spots where smoke sits stagnant.I have an excellent cigar collection. Perhaps a Fuente Opus Opus X would be the perfect blend of taste and stagnant air detector. I suspect care must be given when introducing smoke into the case by using a fanless opening. Therefore, gently open a side panel to a minimum and with great care, exhale the smoke in a controlled and steady fashion so as to allow the case to fill gradually but only in the section of the opening -- the correct technique should introduce just enough smoke to fill 1/4 of the case and enough time to reclose the side panel allowing the smoke to circulate nearest the front fan. Now watch the smoke drift and swirl looking for patterns of slow movement or none at all. These are your dead spots.

Upon locating these dead spots reorganize the cables and fans for optimal air flow without compromising the areas already adequately cooled. Make sure you have positive pressure within the case by adding yet another intake fan lest this second phase will achieve less then optimal results. Light a second cigar and for this I recommend a Te'amo Maximo in a maduro known for its great nutty and coffee flavor taste as well as high smoke density -- it is simply the perfect Mexican cigar for this occasion. Gently blow the smoke directly into the slowest fan intake allowing for quick swirl and circulation throughout the case. A second observer may be required being as you will want to exhale for a longer period of time then in Phase I above while occasionally puffing a smoke ring the approximate diameter of golf ball or raquet ball depending on the situation (obviously, an 80mm fan only needs the golf ball size and a 120mm fan the raquet ball size smoke ring). The second observer will note any remaining dead spots and recommend appropriate changes.

When all is perfect, go have a drink at your favorite cigar bar celebrating with an Aston Cabinet #7 in a plain wrapper. This cigar is mild, flavorful, and smooth, best enjoyed with some brandy.

Until next time, have a good day frag'n everyone in sight, and we will return with more tips for your PC health and wellness while maintaining the style and sophistication you so richly deserve. Go on, pamper yourself, you won't regret it.

-- nomadicus

[PeanutButterSnake{CLR}]

LOL @ Nom!

[KillerRabbit]

Given your setup, I would suggest using it as an intake. Its best to get some fresh air blowing right at the cpu heatsink and it will get your case closer to a positive pressure (otherwise you would have one 120 blowing in and the other 3 blowing out). If you are really worried about cooling though, you should really invest in a better heatsink and some arctic silver thermal paste.

[Mr_Hat]

LOL @ Nom!
Cigar choice is vital when it comes to blowing smoke into your computer. Thank god he caught me in time!

[Mr_Hat]

Given your setup, I would suggest using it as an intake. Its best to get some fresh air blowing right at the cpu heatsink and it will get your case closer to a positive pressure (otherwise you would have one 120 blowing in and the other 3 blowing out). If you are really worried about cooling though, you should really invest in a better heatsink and some arctic silver thermal paste.
Actually got the silver paste already. Any recommendations on CPU fans though? Right now I'm using the standard A64 heatsink and fan that came with the CPU. It's an Athlon 64, Socket 754. I don't want anything too incredibly noisy. I'm also very cautious about vibration, and some of those big bulky ones can actually cause more damage than anything (I had a copper orb on a K7 that actually cracked my motherboard). I've always used the side panel fan as an intake fan because I've noticed a slight drop in ambient temp and CPU temp compared to using it for exhaust.

[ViTO]

do this.... Get someone who smokes heavy ( he he ) or a can of smoke and blow it into your case. look for dead spots where smoke sits stagnant.I have an excellent cigar collection. Perhaps a Fuente Opus Opus X would be the perfect blend of taste and stagnant air detector. I suspect care must be given when introducing smoke into the case by using a fanless opening. Therefore, gently open a side panel to a minimum and with great care, exhale the smoke in a controlled and steady fashion so as to allow the case to fill gradually but only in the section of the opening -- the correct technique should introduce just enough smoke to fill 1/4 of the case and enough time to reclose the side panel allowing the smoke to circulate nearest the front fan. Now watch the smoke drift and swirl looking for patterns of slow movement or none at all. These are your dead spots.

Upon locating these dead spots reorganize the cables and fans for optimal air flow without compromising the areas already adequately cooled. Make sure you have positive pressure within the case by adding yet another intake fan lest this second phase will achieve less then optimal results. Light a second cigar and for this I recommend a Te'amo Maximo in a maduro known for its great nutty and coffee flavor taste as well as high smoke density -- it is simply the perfect Mexican cigar for this occasion. Gently blow the smoke directly into the slowest fan intake allowing for quick swirl and circulation throughout the case. A second observer may be required being as you will want to exhale for a longer period of time then in Phase I above while occasionally puffing a smoke ring the approximate diameter of golf ball or raquet ball depending on the situation (obviously, an 80mm fan only needs the golf ball size and a 120mm fan the raquet ball size smoke ring). The second observer will note any remaining dead spots and recommend appropriate changes.

When all is perfect, go have a drink at your favorite cigar bar celebrating with an Aston Cabinet #7 in a plain wrapper. This cigar is mild, flavorful, and smooth, best enjoyed with some brandy.

Until next time, have a good day frag'n everyone in sight, and we will return with more tips for your PC health and wellness while maintaining the style and sophistication you so richly deserve. Go on, pamper yourself, you won't regret it.

-- nomadicus

Ok I didn't mean to offend you as a smoker :shock:

Your post was funny and maybe I deserve it BUT.....

Tracing smoke is commonly used in all sorts of detection INCLUDING MY COMPUTER !!!

Yes in retrospect my post does come off bad, I am sorry for being alittle slapstick. My posted point was, there are numerous ways of cooling a case with fans. I see no standard to what it should be.

In point, what works for your case wont work for mine. Here is my current cooling configuration...

120mm Front Intake w/ Filter x 2
120mm Rear Exhaust w/ Filter
80mm Top exhaust
Side Cross Flow Intake Motherboard Cooler. (specific to this case but could be modded into anther case )
Since I had never seen this type of case/motherboard fan which is on the right side and runs vertical almost the length of the case. I was curious as to how much air it would move. My ram is set horizontal on the motherboard to increase air flow so this was said to be the best combination. Most ram is set vertical on the motherboard and reduces the flow over the board. SO....

Out came the Low-Toxic Tracing Smoke. I only had the match stick form and not the can, so I lit it and held it in front of the fan to see the movement thru the case.

I did not mention the details of tracing smoke and the need for a clear side panel. For that I will accept my Nomadicus punishing post. :roll:

I have been modding cases for a few years now, so side windows to me seem kinda standard. I forget hat at times.

I will be more mindful in the future. In the mean time pass over one of those Opus X babies and lets light up.


Motherboard fan...
.http://www.coolermaster.com/index.php?LT=english&Language_s=2&url_place=product&p_serial=STF-B01-E1&other_title=STF-B01-E1Cross%20Flow%20Fan

Tracing Smoke...
http://www.powertoolwarehouse.co.uk/product_info.php/cPath/98_532/products_id/2192?osCsid=d44a82569494aae4113d6d185d51e713 :D

[Nomadicus]

Ok I didn't mean to offend you as a smoker :shock:

Your post was funny and maybe I deserve it BUT.....
. . .
Yes in retrospect my post does come off bad, I am sorry for being alittle slapstick.Now I am going to apologize since it was not meant to be sarcastic or negative. In fact, I did take you seriously and started a more serious response but the muse simply took over me and I went on a creative writing jag. It was something I just had to do, but it was not meant to punish you in any way.

Tracing smoke is commonly used in all sorts of detection INCLUDING MY COMPUTER !!! I've learned a lot from this and appreciate it.

I will be more mindful in the future. In the mean time pass over one of those Opus X babies and lets light up. No harm done and my humidor is open to you any time. :sun:

[ViTO]

Nomad, you know I love being pwnd by you and all the others.

:group: I love this place and the people :group:

[{CLR}geneSW]

Any recommendations on CPU fans though? Right now I'm using the standard A64 heatsink and fan that came with the CPU. It's an Athlon 64, Socket 754.

Volcano11+.

Copper heatsink with a 80mm fan that can get up to 4800+rpm's. just over 40 cfm of air flow like that. I actually had to get it for my sempron 3000+. Keeps it at about 50c when i'v got it running at about 2100 rpm's. Also, the volcano11+ series has 3 different fan controll options. One is what I like to call "self controll". It uses a temp probe to check the heat of the cpu and adjusts the fan speed as needed to keep the cpu cool (around 50c I think). You can also have a front or rear controll area. Mind now that you cannot have both the temp probe and fan controlls going at the same time. I'll see if I can pull up a link if you havn't made a choice by now.

[{CLR}geneSW]

120mm Rear Exhaust w/ Filter


Seriously. Does a excause fan need a filter? I fail to see the point of having them on the exhaust.

[KillerRabbit]

Yeah, dont need filters on exhaust fans. All it does is restrict air flow

[Mr_Hat]

Seriously. Does a excause fan need a filter? I fail to see the point of having them on the exhaust.

We don't want dust and other harmful particles escaping!

[{CLR}geneSW]

Seriously. Does a excause fan need a filter? I fail to see the point of having them on the exhaust.

We don't want dust and other harmful particles escaping!

as if ozone at sea level isn't enough! there might be dust! *Grabs oxygen tank for dear life* lol.

[{CLR}geneSW]

here's the link to the specs of the cpu heatsink/fan I use.

http://www.thermaltake.com/coolers/volcano/rs/a1725.htm

it's very loud when turned up to max, and it actually pushes more then I thought it did. Don't trust the thermal compound in there though. Use silver or thermal grease. If you don't have either then use what they have.

[Mr_Hat]

here's the link to the specs of the cpu heatsink/fan I use.

http://www.thermaltake.com/coolers/volcano/rs/a1725.htm

it's very loud when turned up to max, and it actually pushes more then I thought it did. Don't trust the thermal compound in there though. Use silver or thermal grease. If you don't have either then use what they have.

That's the thing that sucks about some of these upgraded cooling units. I want the computer to run cool, but I don't want to hear it from the other side of the house. I'm checking out a few liquid cooling solutions.

[KillerRabbit]

I'm not sure how much you are willing to spend, but since you are looking at liquid cooling, I'm guessing its not much of a problem.

If you want great cooling and low noise, the Zlaman CNPS7000/7700s are rather good, but they run at $40+.

Thremalright makes some nice heatsinks, you could put a quiet fan on one. Though unless you are doing a lot of overclocking, you probably dont need to spend that much.

Slightly cheaper is Thermaltakes Silent Boost. I never tried their one for 754/939 but I have the socket A one and it was very quiet and cooled well. It runs about $32 on Newegg.

I'm sure there are pleanty of others. These are just the ones I have experience with or have heard many recommendations for.

[ViTO]

120mm Rear Exhaust w/ Filter


Seriously. Does a excause fan need a filter? I fail to see the point of having them on the exhaust.

MY BAD !! Typo ... I AGREE SEIKO

But I would recommend to anyone who has 120mm fans, the thin gaskets they sell for noise reduction. With three 120's you do get some humm, although its really not that bad.

I bought a fancy 80mm ANTEC FAN w/ leds and its LOUDER than any of the 120's. What Crap.

does anyone do FANLESS. I mean those Cases and Power Supplies with the fins ???

[Nomadicus]

Fanless? Not the way I overclock -- lol
I've never heard of the type of case you mention. Powersupply, yes, but case no. Where are they on the internet. I'd like to see one out of curiosity.

[ViTO]

I have seen the smaller size cases used in custom Multi Media PCs. " Noiseless "

here is a link for the larger...Zalman TNN-500A

http://www.devhardware.com/c/a/Computer-Cases/Zalman-TNN-500A-Fanless-PC-Case-Review/

[Devilguns]

I'm using the Zalman 7000 with Arctic silver 5 and knocked 14 degrees celsius, thats about 25 degrees F, off my temps. When I was using the stock Intel heatsink with my P4 3.0 it Idled at 44c, now it's at 30c. Load under stock would reach the high 50s, now it never gets out of the 40s. I have it set at the max and you don't even hear it. I also like the Coolermaster silent fans. I have a Sony comp with only three fans and it's louder than my gaming rig that has eight fans.

[ViTO]

I'm using the Zalman 7000 with Arctic silver 5 and knocked 14 degrees celsius, thats about 57 degrees F, off my temps. When I was using the stock Intel heatsink with my P4 3.0 it Idled at 44c, now it's at 30c. Load under stock would reach the high 50s, now it never gets out of the 40s. I have it set at the max and you don't even hear it. I also like the Coolermaster silent fans. I have a Sony comp with only three fans and it's louder than my gaming rig that has eight fans.

AH YES .....the CoolerMaster fans are shhhhhhh quite. I have the Stacker Case by them and all three 120mm fans are very quite in comparison to other.

[Nomadicus]

. . . 14 degrees celsius, thats about 57 degrees F, off my temps.Not trying to be picky, but a differential of 14C is not 57F, it is 57 - 32 = 25F.
Nice results though and quiet too!

[{CLR}geneSW]

what temp is your house at if it's sitting that low? or do you have some other way of getting the air over the heatsink that low because the last time I checked moving air dosn't cool. It just feels cooler.

[Devilguns]

Hey thanks for the correction Nom, I'm a product of NY public schools lol.

[Mr_Hat]

what temp is your house at if it's sitting that low? or do you have some other way of getting the air over the heatsink that low because the last time I checked moving air dosn't cool. It just feels cooler.

Maybe he lives in an igloo.

[Mr_Hat]

I'm using the Zalman 7000 with Arctic silver 5 and knocked 14 degrees celsius, thats about 25 degrees F, off my temps. When I was using the stock Intel heatsink with my P4 3.0 it Idled at 44c, now it's at 30c. Load under stock would reach the high 50s, now it never gets out of the 40s. I have it set at the max and you don't even hear it. I also like the Coolermaster silent fans. I have a Sony comp with only three fans and it's louder than my gaming rig that has eight fans.

After reading your post and several reviews, I decided to pick up a Zalman 7000 from a local distributor and it's incredible. Even at the highest RPM it is much more silent than the stock CPU fan that came with my A64. They didn't have the all-copper model so I had to settle for the copper/aluminum version. My CPU is running 12 degrees cooler and I only paid $18 for the thing so you won't hear any complaining from me!