"Frank R. Brown" wrote:

> We have an in-win q500 full-tower case.
>
> The power supply has a fan blowing out the back.
>
> We added an intake fan in the fan cage on the lower front.
>
> On the upper front we have a bay-cooler drive fan blowing in.
>
> There are two places in the case on the back where we could
> mount additional fans: one on the lower half (where the mother-
> board and the add-on cards are), and the other on the upper half
> (where the power supply and the drive bays are).
>
> If we were to add more fans, I suppose the upper fan should
> be an exhaust fan.
>
> If we were to add a fan on the lower back, should it be an
> exhaust fan (air blows front to back) or an intake fan (air
> blows bottom to top)?

Unless your doing something special, a good rule of thumb is fans in
back blow out, fans in front blow in. The idea is to pressurize the
case, that's why you leave the covers on. Your bottom front fan will
suck air in, hot air rises so the fan on the back sucks it out. In an
ideal scenario you have the same amount of air coming in as you have
going out.

HTH,

Jose

        The NOSPIN Group provides a monthly newsletter with great
       tips, information and ideas: NOSPIN-L, The NOSPIN Magazine
             Visit our web site to signup: http://nospin.com