My mom's computer is an old sony vaio, and the idle temps are pretty high. I thought I could lower the temp down a little, by using a spare 140mm fan, I have lying around. Theres no place to mount a fan, but I took the top off, and now the fan is sitting on top, as an intake. This case does not have any intake or exhaust. The only possible exhaust would be the power supply. So....sitting on top, should this fan be an intake or an exhaust? I was thinking an exhaust, because the fan is sitting on top, it could be like a blowhole, since heat rises. But I decided to go intake on top because, theres no intake at all.