Clean your exhaust fan regularly. It’s not a difficult job; simply turn off main power to your bathroom, locate the fan, remove the vent cover, then remove the fan blade if possible. (Take care of those screws — you won’t want to lose them!)
Use mild soap and warm water to clean both the cover and both sides of the fan blade. Let them fully dry before reinstalling them. While they’re drying, inspect the vent and clean whatever you can reach. If you need a quick fix and don’t want to take the assembly apart, blow the fan and vent with canned air. It won’t get rid of all debris, but it’s a quick refresher.
If you want to replace your exhaust fan, or install a new one, make sure you hire the right person for the job. Some localities and states allow handymen to do this job, but some require a licensed electrician. You’ll pay between $165 and $350 for this work.
When hiring, ask them the right size fan you need. All ventilation fans have an airflow rate measured in cubic feet per minute (CFM). The Home Ventilating Institute recommends one CFM per square foot of bathroom area. Add 50 CFM for each toilet, shower and tub. You might need a higher-rated fan for a bathroom with a particularly high ceiling.
Some fans are louder than others. Be sure to buy one with a noise level you can live with.