Fan configuration again
With the addition of a new front bezel (i got free off directron) as well as me finding some old fans and a new zest for modding its time for me to break out the dremel.. I would like input about this configuration. I think i might want some more cfm's blowing inside, perhaps I will only have one tornado blowing out. Anyways here is a rough pic with the air flow, give me a holla at watcha think!
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With the shown configuration you are at 314 out and 203 in...If you run 1 tornado you would be 195 out and 203 in which would be pretty close...so the 1 tornado config gets my vote
Those fan's don't "suck air in" they just blow it across the heatsink and swirl it around in the case.
Having the high CFM fan up in the top like you have and feeding it with the fans in the front lower and the side down low like that will keep the convection going since hot air naturally rises anyway.
btw, im currently taking physics right now, so i might ask areound for a more concrete resource, but i dont feel like wasting my teachers time lol
Your best bet is as Ryder says, CFM in as close to equal to CFM out as possible.
It is how much air the fan moves at xxx RPM's. The rating on most fans is their CFM at full speed (which you will be at full speed if you are NOT on a fan controller)
So you add up the fans CFM going in and what is coming out....then you try to make it equal.
Fans going out should be near the top 1/3 of the case....in should be at the bottom 1/3 (whenenver possible)
You may not want the tornado there...but some type of fan there is aces in my opinion.
What in your diagram is already there....stuff you don't have to dremel?
1 in front...2 in back and 1 in the side?
If you haven't seen this...there is some good discussion here: http://www.bleedinedge.com/forum/showthread.php?t=3285
Just experiment, is what I say.
The ideal is equillibrium - ambient atmosphereic pressure inside the case. But if there is an imbalance of 'out' and 'in', it's better to have slightly more exhaust volume. The slight negative pressure will cause air to rush in the intakes at a greater volume than otherwise effected by the intake fans alone. Considering what Madmat said - I hadn't heard of that before. Learn something every day. I don't think, however, you need to be concerned about a fan stall, as that would probably require an extreme negative pressure (vacuum).
The dynamics that come into play when there is more intake volume than exhaust, positive pressure, is that much of the warm air in the case swirls around instead of being quickly exhausted.
but the question still stands..tornado on top or a 120mm fan..cuz as of now, i havnt found a 120mm fan that has a good amount of air intake
Even with the Tornado at the back top under the PSU....you will not starve the PSU for air as long as all the flow is not out on every fan.
a 120mm will be quieter and move the same amount of air as a smaller fan running faster.
This is easy to browse and give you some ideas for models of fans...then you can search the net to find possibly better pricing, etc.
http://www.frozencpu.com/search.html?mv_profile=searchstring&mv_sort_field=description&mv_matchlimit=33&mv_session_id=qKgZXT3I&mv_searchspec=120mm+Fan+CFM
Actually I've seen this happen several times over in the power supply sub-forum over at [H] Forums. There was one guy that RMA'd 3 PSUs because they were pulling in air rather than blowing it out and the fans in the PSUs were running way fast. 1 PSU he RMA'd, replaced it with another PSU (different brand) and it was still sucking air so when the first came back he put it in and still had the problem.
All his fans weren't exhaust either, I think there was about a 40 CFM difference in intake and exhaust with the exhaust being the higher number. If the case is only going to allow a few CFM of leakage the rest has to go somewhere. Airflow like water and electricity follow the path of least resistance. If the PSU is that path that's where the air will come from.
The reason I say max and half is because the distance from the front of your case to the mobo is roughly 2x as far as it is for the side fan. If you put the side fan at full speed, its going to cause the air from the front fan to be sheared into generally a smaller space leaving other parts at higher temps. I use this config in my GF's intel gaming rig and the preshot rarely gets above 48C at full load. Also, less fans are going to mean less consumed wattage and less strain on the PSU.
Now, on my own gaming rig I have 2 80mm in front, 1 120mm on the side, and 2 80mm on the back. The 120 is centered over the middle of the mobo, so the air hits the mobo and is deflected across it. 1 80mm is blowing across the HDD's and the other 80mm is blowing from the front across the 2 GPU's (7800GTX's OC'd to 510/1320 @ 58c full load on stock coolers) with 2 exhause 80mm's in the rear. This configuration keeps my towers internal temp around 34C and the CPU temp at 36C full load oc'd to 2.7 (4000+).
I'm going to be getting a new chieftec full tower soon to start modding up again. Going to try some alternate configurations with the fans to see what else works, but the above has worked the best for me so far.
A slight negative air pressure created by the exhaust is good. But don't get carried away. The exhaust pulling slightly and I mean slightly more out than the intake pulls in makes for a good flow.
In your drawing you have way more going out than comming in. Balance is the name of the game.
You have 128 cfm comming in from the front.
You have 46 cfm going out the back.
You have 75 cfm comming in the side.
You have 238 cfm going out the roof.
You have 30 cfm going out the psu.
Ok so you have 203 cfm comming but 314 cfm going out. Way out of balance. You have a 111 cfm difference between the exhaust and the intake and it favours the exhaust. If you are determined to go this route I would suggest not using the two intake fans in the front at all but instead just cut out the holes as if you were. With that much exhaust cfm's you don't need intake fans. Go total passive intake.
Look in my profile and get my forums address and come by and scope out the stuff I've been having fits with. lol
They had multiple probes throughout the case and on the chipset,gpu, and cpu.
They tried such combos as front only, back only, front and back, front and blowhole, rear and blowhole, front rear and blowhole, and the other combos such as a fan on the side.
Long story short, the configuration with one front fan and one rear fan kept the computer its coolest, I am not sure why, as you'd the more air you move the cooler you could keep it. The way I figure it, is my case is *roughly* 2176 cu. in. that comes out to 1.25 cu ft. Although, there was a close second if I remember right, the one with front/back/side kept the gpu slightly cooler, but also raised the cpus temperaturea few degrees, as im sure the side fan mess up the air flow.
So if I only have a 30 cfm fan, that means that the air in my case is being exhanged 24 times per minute. Although, Im sure we can all agree that the fans probably arent going to be putting out a full 30 cfm, as im sure the manufacture stretches the number a little bit.
I have 3 fans on my case, 1 in the front, 1 in the back, and one on the side, I really hadnt planned the one on the side, I just had an extra red led fan, so I figured what the hell, lets do it, my computer aint that fast or super nice anyway, so lets rice it up!! lol. I just figured I'd finish the job, because my case is from like '94, and I painted it midnight blue, it has custom side and top windows cut in and plexiglass riveted to the case. I was going to put a fan up top, but there is no room.
That is why I call my computer the ricer, because like a true ricer, I took a pos case(car) and tried to make it look better by putting flashy crap and neon on it. And like a true ricer, it has its problems, like the gaping hole in the front panel where my (ex)girlfriend *kicked* out three drivebay covers and broke them all while we were 'playing':bigggrin:
ok, sorry about the threadjack, just had to put my $.02 in, if I could find that article I would link to it.
Now, should I add a vantec stealth 120mm fan directly on top of my OCZ modstream (if i get it) it rates at 53cfm. Would that be completely useless or would it help dissapate the heat which accumulates above the PSU
i bought 5 orange UV fans from frozencpu, they operate at 34cfms, 4 of them will be the exhaust (2 on top 2 on the side) one of them will be an intake on the side. As an outtake i also have my 600w modstream coming in (yay) and as intake i have a 119cfm tornado and a 72cfm smart fan,
that is 221 in and 136 out (not including the modstream) so im guessing after the modstream is in, it'll be about 200 out.
So is that too big of a difference, or should everything work out well
But since you are probably correct about the PSU
jeez who would have thought that this would take this much thought