Check for loose blades or screws, balance blades with a kit (weights included), or tighten the downrod canopy.

Remove the cover, vacuum dust, wipe blades with soapy water, and clear exterior vent flaps.

Calculate based on room size—1 CFM (cubic feet per minute) per square foot of bathroom area. For example, a 50 sq ft bathroom needs at least a 50 CFM fan. High-humidity areas may require stronger models.