how many case fan you need?

[watchmen77]

I building a 1.4ghz athleon system.
i have one fan at the power, another one at the back.
there is another openning in my case that is at the bottom.
i just wonder if i really need to put in a third fan and not sure if it does anything
if it is at the bottom since it will be covered up anyway when the system is stand up.
or else where i put another fan? is slot fan any help?

 

[SWScorch]

I'd recommend putting as many fans in as will fit. If you get a good slot cooler, it will help, but junky ones are just a waste of money.

 

[0beron]

The "usual" (and I use that term VERY loosely) setup is intake fan(s) in the front and exhaust fan(s) in the back. Try to balance the air flow though some will swear that a negative pressure in the case is better for cooling.

Doesn't sound like the fan at the bottom will do much good if you stand the case up and the hole is blocked off.

I guess it all comes down to what your case temps and CPU temps are? If you are happy with them, save yourself the agony and don't change anything.

 

[tazdevl]

In my experience with cases, I have found that a slot cooler did diddly. Then again, my old case had 5 fans in it already not counting the PSU.

Definitely need to put a fan on the front of the case. That's where all the components get the cool air (front fan pulls in cool air and rear fan blows hot air out). If you are buying fans, I'd recommend Panaflo fans. PCMods has them @ reasonable prices with good service. They push a lot of air and are the quietest on the market. In addition, you might also want to upgrade the rear case fan if it isn't a decent one as well. Your PSU fan does diddly squat for the case unless it's a Enermax dual fan PSU (92MM fan right above CPU pulls hot air off it and another blows it out the back). It just cools the Power Supply which produces a fair amount of heat on its own.

Only other option would be to install a fan on the side of your case to blow cool air on the CPU/video card or drill a hole up top to pull hot air out of your case with a fan (called a blowhole). I'd say an 80/92MM fan would do the trick in either location. I'd recommend 92MM because Panaflo makes a nice Low Speed fan that is very quiet but pushes a lot of air.

A bottom fan does you no good zero zilch.

If you are planning on overclocking your CPU or any other components you need a fair number of fans. Tbirds product a lot of heat when run @ stock speeds, even more heat is produced when you overclock.

Here's what I"m doing to my new case, a LianLi PC60 USB.
-Upgrading 2 front case fans to Panaflo 40CFM (cubit feet per minute)
-Doing same thing to rear case fan
-Have Enermax dual fan pulling hot air our of case
-Probably going to install a blowhole on top of case (with Panaflo fan I mentioned) to pull hot air out. It also does not disrupt the airflow from the front to the rear of the case.

When you ask questions like this it helps us to know what kind of case you have. All cases are not built equal. Some cases are very well designed and have great airflow from the front to the rear of the case. Others don't. It makes it tough to offer advice if we don't have the full picture.

 

[watchmen77]

thanks for reply.
my case wasn't that great. only 45 cheap with 400watt power.
it has no front openning as long as i can see.
i have one running right now with 1.2ghz tbird and with 1 fan(another just power fan).
at back. i don't really see what u mean front fan since most of case i saw at the pc show
that don't have front openning.
and my 1.2ghz pc right now give me about around 35-40 for case temp. and i never
overclock my pc.