Most people know that their bathroom exhaust fan is there to remove odors, and some understand the important role it can play in controlling humidity, and thereby discouraging mold – particularly in areas that have a shower or bathtub as well as a toilet.  (If you’re showering in a room with a bathroom exhaust, always keep it on while you’re showering!)
It can be easy to not notice – or to ignore – a dirty bathroom exhaust.  Why worry about it?  After all, it isn’t recirculating air back into your HVAC system.
The answers are:
•    If the fan is dirty, it can be a lot less efficient and effective.  Blades in a typical bathroom exhaust fan are close together and some are curved for maximum efficiency.  Dust and dirt can build up in the cupped area of the blade, turning it into a flatter surface, in addition to creating more weight for the motor to spin. 
•    Dirt can build up in the damper, cutting down the airflow or getting it stuck in one position.
•    Dirt building up inside ducts can cut down on airflow, or dislodge and help to clog the fan or the dampers.
•    A dirty system can be noisier.
If dirt is building up on the grille, that could be a good indication that it’s time to have the system cleaned.  
Airways cleans all types of exhaust systems, including bathroom exhausts.  Call us if you need us.