Interesting write up, and actually a problem I've been dealing with lately, but I have a few issues with how the OP went about the design.

1) straight from design to cad to getting samples built? Might have been better to hack together something at home. The prototypes could have been made from old orange juice containers and other random bits of plastic, cardboard, etc. etc. 2) Unfortunately, this doesn't solve the issue in my flat. The problem is not enough airflow to dry the towel, so I hang my towels out by the window, not in the bathroom.