Question about DC Motor Control with Raspberry Pi

You have mentioned the voltage and current rating of the fan that you are planning to use.

But if it is a small fan, you are good to go with the same value of capacitor 

First of all, for getting your issue get resolved; mention the specifications of the motor/fan you want to control with your raspberry pi. If the fan is of 5V, which is commonly found in computer CPU, then you can use it with the raspberry pi. If the voltage of fan is of 6V, 9V or 12V, then you have to use switching modules/parts to turn you fan ON/OFF at a specific condition, you set. Here I would like to recommend you to visit SSLA for getting better assistance from their technical support team.

Please specify the dc fan ratings, if you are using a small 5C DC USB fan, then no need to change the capacitor.

First of all, to get your issue resolved; mention the specifications of the motor/fan you want to control with your raspberry pi. If the fan is of 5V, which is commonly found in computer CPUs, then you can use it with the raspberry pi. If the voltage of the fan is of 6V, 9V or 12V, then you have to use switching modules/parts to turn your fan ON/OFF at a specific condition, you set. Here I would like to recommend you to visit Sierra Software Ltd. for getting better assistance from their technical support team.