My computer has a few fans in it already. I just installed vent fan (took it out of my old computer)

the vent fan is not an intake fan, understand? It's one of those that ties into a pci slot hole (but not into a pci slot on the mobo) and connects to the power supply.

Does it make much of a difference in cooling, or does it not really matter that I installed it?

Question: does it make a difference in temperature / help with dust, or not really?

thanks