Newbie making a power supply.

I have a 400VA transformer outputting about 50 volts at around 8 amps.

I'm making a case to house it along with the electronics. I'm cooling the motor stepper drivers and the rectifier with a fan cooled aluminum heat sink.

I'm currently planning to have all the airflow be external to the box.

Will the transformer need a fan over it, or is it going to be okay in a sealed enclosure with no fan?