PC fans can be very deceptive. While they may look small they have alot of power behind them and especially if used in a grow box as small as yours will be a HUGE help. I am actually going to grow a plant in a few months inside of a PC :P The CPU as well as the motherboard inside of a computer gets very very hot as there is an insane amount of data being processed at once. If PC fans weren't really great at what they do, Your PC would probably have melted by now :twocents: