Micro Cooling Fan cooling fin area is larger, the better?

By "Micro Cooling Fan" and bring the cold air blowing away the heat of the heat sink, and a fan that can be the size of the heat conduction number of the heat sink, in general, the contact area of the heat sink and the air big, "Micro Cooling Fan" cooling effect is better, but this argument is a certain premise is that in the case of the chassis has enough free space. If the computer's chassis had space for heat dissipation is not large, there is not enough space left in the case, a very large area of the heat sink is mounted to the chassis is difficult, even if barely able to install the chassis, which would have blocked much of the contact area fins hot air around quickly dissipated, leading to an overall internal chassis temperature is too high, so that the impact of "Micro Cooling Fan" operating performance, so I recommend an area the size of the heat sink and chassis should be selected to match, not a place pursuit of large area heat sink.