Originally Posted by z_one
I'm not sure about this but I think it's better to keep the case closed and make sure there are at least both a rear exhaust fan and a front intake fan to make air circulate through your case.
Some people argue that if you leave your case open then the air inside it is going to be stagnant which means aeration but no ventilation. This also means that the air around your components is not moved. It could create local heat focal points (sections on a certain chip that get hotter than the rest of the chip).
On the other hand, if you have a closed case with no holes/cracks/openings and you correctly install your fans then you would force the hot air around the components to be continuously moved and replaced with newer and cooler air.
It's up to you but I prefer to leave my case closed and create proper air flow inside it.
Yes, you are right. According to common physics and Scientific Laws...
But if the fans in your case aren't doing thier job, than open that baby up.