How to determine what size. Bath is W5 X L9 X H7.5 sink toilet & tub-shower

How important is the 'low noise' option. (It's only on for 10 minutes... there are no conversations to shout over fan noise. Or is it mostly noise from 'vibration')

Speaking of 10 minutes. Would like a timer.

Thank you, SCrane43

The timer is an option that can be bought separately and does n't usually come with any fan. You have just over 330 cu/ft of space so buy a fan that pulls at least enough air to give 8 changes of air per hour. You need a small fan of 50 cfm or higher, much higher and you wasted money. This is a small fan so you can afford to buy a low noise fan but that is strictly up to you, we will never hear it but you and future owners will.