Exhaust fans: Your home's secret MVP | PEMCO

​Besides the toilet, they're probably the most unglamorous appliances in your home. 

Any idea what we're talking about?

They're 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 (laundry), 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 using your fan 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, we hate to break it to you, but 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.

Tips for cleaning bathroom and laundry room fans

Turn off the circuit breaker that serves the fan to remove any risk of electric shock. Remove screws or 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.

Tips for cleaning 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.

Keep your home dry and avoid excess moisture

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.

2. 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.

3. Don't expect your 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 (which, remember, can lead to mold or rot over time, which often is not covered by typical home policies). Other common culprits are hidden water leaks and poorly drained soil near your home's foundation, among others.

You can learn more ways to prevent water damage here.

Stay dry, PNW!