[Porsche-O-Phile]

It helps to have dry hot air but it's not absolutely necessary. Regular hot air will do the job, it just might take more of it.

When the weather gets really crappy and everything is wet / damp / sloppy it helps a lot to have the defroster work quickly and effectively.

I'm hoping to move somewhere I won't need to worry about defrosters in the next couple of years...