Cracking open the door is not an option when the kids are around!!
I hadded a Bathroom Door Air Vent Grille 455mm x 135mm / 18" x 5.3 inch Two Sided Ventilation Cover and no problem with air flow!! My wife and 2 kids take there shower so hot they totally empty a commercial grade 60 gallon hot water tank by them self!!!
I had a 50 cfm for a 8x8 bathroom now a Broan-NuTone AE110 Invent Flex Energy Star Qualified Single-Speed Ventilation Fan, 110 CFM 1.0 Sones and no more humidity!! Dont even have to keep it on anymore….