Noise the more expensive units are well engineered and will therefore be much quieter that the cheap fans. It will turn off the fan after 10 minutes if it was turned on manually but only if the humidity is below a set value.
Normally fans have some form of run on normally set to about 15 minutes.
Humidity sensing bathroom fan won t turn off. Not linked to a timer because they re linked to a humidity sensor as opposed to a timer they won t turn off until they have got the humidity level down to the correct level. I did find with my fathers shower it took a long time before the fan turned off clearly the room was too damp. Some but not all fans with a pull cord will have a neon light to indicate when the fan has been pulled to override.
Bathroom fan won t turn off. It will turn on the fan if humidity rises above a set value. I have to go down to the main floor to shut off the fan.
Finally it will turn off the fan no matter what after 20 minutes. Advantages of humidity sensing fans. On the other hand it shuts off when the indoor moisture level is low.
If you set the air exchanger to keep the air at 40 humidity but it s 50 inside the bathroom fan will keep running until it s at 40 no matter what the switch is set to in the bathroom. The guy who installed it advised to leave them running for a few days to see if they turn off but to no avail. The dual sensor technology for motion and moisture automatically turn on while the humidity level is high.
Also humidity sensors are popular. They should have a decibel db rating on the box. They have been set to 50 humidity but will not switch off unless turned off via the switch.
Conveniently it includes a speed selector switch that allows you to choose the fan speed from 50 80 and 110 cfm. If your humidity controlled fan has a pull cord it is also possible that somebody has pulled the cord to the override position in which case the fan will run continuously until switched back to the sensor mode. He s coming back to re adjust the setting but if that doesn t work he advises to call the manufacturer.
Then the switch in the bathroom won t shut it off.