Your home’s exhaust fans can help solve your moisture problem

​Besides the toilet, they're probably the most unglamorous appliances in your home – your bathroom, laundry room and kitchen exhaust fans. And just like your toilet, they can cause expensive damage if they're not working properly.

Exhaust fans collect and safely vent steam produced by hot showers, hot-water washing and cooking. That matters, because with nowhere to go, steam condenses onto cooler surfaces and can lead to mold and mildew growth. Besides looking nasty, biological pollutants, as they're called by the Environmental Protection Agency, sometimes can lead to health problems. Excess moisture also causes wood rot – expensive to fix and not typically covered by homeowners insurance.

Make fan use a habit

1. Showers. 

Not only should you run the fan during your shower but for 20 minutes after to help remove moisture-laden air. If your bathroom has a modestly positioned window, open it a crack during showers. The added air circulation will assist your fan in clearing the steam.

2. Laundry.

 If you wash mostly in cold water, laundry room steam isn't much of a problem. But when you wash in warm or hot water, run the fan during the wash cycle and for a few minutes longer into the rinse cycle, which is almost always cold.

3. Kitchens. 

If you're boiling water or frying anything with oil, cover pans when possible and turn on the range-hood fan to remove steam, smoke and cooking odors. As in the bathroom, crack open a window to promote air exchange during cooking.

Maintain your exhaust fans
If you're thinking, "Wait, what? Those things need maintenance?" you're not alone. And the answer is yes. They need to be inspected and cleaned at least annually. Kitchen fans need cleaning more often if you do a lot of frying.

4. Clean bathroom and laundry room fans. 

Turn off the circuit breaker that serves the fan to remove any risk of electric shock. Remove screws or, on newer fans, tension clips to release the fan grate. Wash the grate in warm, soapy water to remove dust and residues like hairspray that can coat and gum up bathroom fans. Use a handheld vacuum wand to remove dust from the fan assembly and wipe with a tightly wrung damp cloth if you notice residue that won't vacuum off. Dry and replace the grate.

5. Clean range-hood fans.

Turn off the circuit breaker that serves the fan. Remove the grease filter or grate that helps keep grease from traveling into the vent pipe and follow manufacturer's cleaning instructions. Some allow you to run them through the dishwasher, others specify handwashing and a few have disposable filters that you just toss and replace. If you have the washable kind, soak it in a mixture of baking soda, vinegar and hot soapy water to start breaking down and loosening greasy gunk. Next, scrub with a plastic-bristle brush and dish soap formulated for grease-cutting. Wipe down fan blades and other interior surfaces with a tightly wrung damp cloth. Dry and replace the grate.

6. Make sure fans are vented to the outside. 

It's possible that an installer took a shortcut when your home was built and vented them inside a wall or into the crawlspace or attic, leading to hidden moisture or mold problems. If in doubt, have your HVAC specialist check the next time they're out to service your furnace or air conditioner.

7. Check that exterior vent flaps aren't blocked. 

We've seen vent flaps painted shut or clogged with leaves. They also can rust shut so that they can't swing open freely when air blows against them, trapping the exhausted air and moisture inside the vent pipe.

8. Don't expect exhaust fans to last forever.

Like most appliances, they wear out. Your range-hood fan has a life expectancy of about 14 years.

Improperly used or ineffective exhaust fans are only one reason why your home may have excess moisture. Other common culprits include keeping the heat turned too low or shutting heat registers in rarely used rooms (while it may reduce energy consumption slightly, the reduced airflow and cool temperatures contribute to dampness and mold growth), hidden water leaks and poorly drained soil near your home's foundation. Learn more ways to prevent water damage and mold in your home on the pemco.com blog.

BONUS TIP: Did you know your water meter can tip you off to a sneaky leaker like a silently running toilet? Open the lid to your in-ground meter and look for a flow indicator, often a small triangle that spins, when water is in use. If you see it spinning, but you know there's no water intentionally running anywhere in the house, you'll want to start checking for possible leaks. In-ground sprinkler systems and toilets are top suspects. Hidden leaks also can occur in the pipe that runs between your home and the street – sometimes a costly fix, but one that insurance can help with if you purchase optional water and sewer line insurance.