I'm going to begin case work very soon for my next mod, and simply need to pick a cooling scheme. I am going to do some significant overclocking without watercooling, so I need a very well cooled case. The case i'm working with is not very big (CM Centurion 5), but I think it should have the traits I need to make a cool and clean case. I have recently been wondering about lower intakes. As we all know, heat rises, so logically the coolest air in a room rests on the floor. I want to raise my case up (with casters) and mount two 120mm fans on the floor of the case as intakes. Here is what i'm thinking about

The bottem fans will be lower cfm than the two exhaust fans, so that the case will still maintain negative pressure, but I'm wondering if this scheme is really the best. This scheme will also cool my gpu quite well, so i'm leaning towards it at the moment. Should I do two fans or just one? Do you think a left panel intake (or two) will be more efficient than the floor intakes?

Well...
Your going to need to filter the bottom fans... lots of dust down there... just look under your case right now...
and those bottom ones are blowing right on your bottom expansion card... you have to remember to look at your airflow 3 dimensionally. I don't see it helping too much like that. Also, I'd be surprised if the air at the bottom (exterior) of the case is a degree cooler than the air at the top (exterior) of that case.

Quote: Originally Posted by ratchetfps I'm going to begin case work very soon for my next mod, and simply need to pick a cooling scheme. I am going to do some significant overclocking without watercooling, so I need a very well cooled case. The case i'm working with is not very big (CM Centurion 5), but I think it should have the traits I need to make a cool and clean case. I have recently been wondering about lower intakes. As we all know, heat rises, so logically the coolest air in a room rests on the floor. I want to raise my case up (with casters) and mount two 120mm fans on the floor of the case as intakes. Here is what i'm thinking about The bottem fans will be lower cfm than the two exhaust fans, so that the case will still maintain negative pressure, but I'm wondering if this scheme is really the best. This scheme will also cool my gpu quite well, so i'm leaning towards it at the moment. Should I do two fans or just one? Do you think a left panel intake (or two) will be more efficient than the floor intakes?

for the record thats alot of MSpaint work you did

nowdepending on the motherboard layout and the drives and cards you could use bottom fans and they could work well, but normally there a hassleand if you case gets surrounded it could causethe fan to get blocked and over work or even die

I figred this when making my case so i developed a simple filtered bottom of case fan idea, i made it were the fan is on an angle (my cpu is on the bottom of the board due the the upside down mounts) and then ducted it to the frontof the case, inbetween the two feet on the front and then will screen it there with a filter causing a suction in the duct with the front opening for intake(this also elps with noise reduction)

just a thougt, i dont know how much work your looking to do

I put in a bottom fan mainly because the ports for air to get out seem to be outnumbering the ports for air to get into most new cases. As long as your case feet are high enough there is plenty of room for the filter. Just remember it blocks your bottom slot, gets in the way of mobo headers, and stuff falls into it like an impeller of doom killing your henchmen rather than your arch nemesis.

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Quote: Originally Posted by carbongraphite and stuff falls into it like an impeller of doom killing your henchmen rather than your arch nemesis.

ever heard of a fan grill??

dont forget about intake clearance. For a 120mm fan you need at least 10cm of clearance for it to get enough air to move it. The small the fan the less clearance. If it wasnt 2am I'd find ya some niffy links but i figure some other insomiac (or student like me) will help.

What do you guys think about a single floor intake in the middle (so my gpu wouldn't tottaly block its airflow) and a side intake? Would that create too much turbulence? As far as having enough clearance, the casters I use provide me with a little under 2 inches of additional height, though I think that should be enough to suck up a decent amount of air.

Quote: Originally Posted by ratchetfps What do you guys think about a single floor intake in the middle (so my gpu wouldn't tottaly block its airflow) and a side intake? Would that create too much turbulence? As far as having enough clearance, the casters I use provide me with a little under 2 inches of additional height, though I think that should be enough to suck up a decent amount of air.

to quote a pro

Quote: Originally Posted by AntiM I remember when Joe over at ProCooling did this big long winded explanation of how air should move smoothly through a case. Low in front to high in back with the least obstuction all fans working in unison. He even set up a smoke test to show how smooth and even the air flow should be and how heat rises and this was the best way to do things. It's a load of crapola. What you want is turbulant air flow. I'm not saying restricted, but turbulent. Just like a waterblock with greater turbulence will allow water to pick up more heat on its way through a water block, the more air swirls around the more surface contact it will make and the more heat it will absorb before it leaves the case. Since this is really hard to predict without running very complex simulations. Just flip your fans over and measure the difference. Keep flipping until you find the best combination of performance with all your fans together.

from this post about fan circulation

Turbulance is a good thing, that your first mistake you just need to have enough cfm to causeit in excess

i say if you add a fan to the floor of your case, you should first have it a high CFM fan, then add a fan grill and make sure it has a filter (which you dont have to buy if you use dryer sheets) and enough clearance to get air flow in general