Bathroom Fan

ashe

Our bathroom fans are inline through the ceiling. A good inline fan will usually beat most wall based fans as they tend to move a lot more air while being quieter due to being in the loft. 

Ours had an overrun timer but we didn't see it because i didn't want it on for 30 minutes every time we went to the loo at night 

instead I installed a small zigbee switch to it, and put a £10 humidity and temperature sensor in the bathroom. Our lights are already in motion sensors with automations to handle those.

lights and fans come on when someone comes in. Go off 10 minutes after motion is no longer detected, any motion resets the clock. 

Fans stay on if relative humidity is above threshold 

lights and fans can be overridden with a small discrete switch if you were just popping in to get something 

lights are also dimmed at night to 10% and fan doesn't come on. 

Leak sensor behind the bath.