Duct vs blower fan (side)

[Sabreguy]

Well I have this cheapo Enermax case that has a grill on the side panel with holes... but here's the kicker.

The holes are a couple of mm bigger than what a 92mm fan could be screw on! So I'm thinking of 3 options:

a)use 1 screw + ties to secure fan to current holes after removing excess grill metal

b)Remove grill metal and convert into duct for CPU. (P4 2.4c)

c)Go nuts and redrill holes and convert to 120mm intake fan.

Just want to ask what are the benifits of a duct vs. a fan that's right on top of a CPU?

Thanks in advance.

 

[Vonkhan]

common sense tells me tht a ducton the cpu would be better ... cant explain it scientifically!

 

[Corporate Thug]

the duct pushes the air directly to the HSF/cpu as where the fan is just pushing air to the general direction of the HSF/CPU, thus the duct cools better