Bathrooms generate more moisture than any other room in your home. Hot showers, baths, running water, and wet surfaces make humidity management a constant challenge. Without proper control, bathroom moisture spreads to other rooms and creates ongoing problems throughout your apartment.
The good news is that bathroom humidity is manageable with the right habits and simple measures. Here's how to keep your bathroom—and the rest of your home—drier.
Why Bathrooms Get So Humid
A typical hot shower releases several liters of water as steam. In a small bathroom, this quickly raises humidity to near 100%. The steam settles on every surface—mirrors, walls, fixtures, even the ceiling. Without intervention, this moisture lingers and can migrate to adjacent rooms.
Bathrooms also accumulate moisture from:
- Running hot water at sinks
- Wet towels and bath mats
- Drying clothes or swimwear
- Leaky faucets or toilet components
- Poor ventilation trapping ambient moisture
The Importance of Exhaust Fans
An exhaust fan is your primary weapon against bathroom humidity. When functioning properly, it removes moist air directly from the bathroom and expels it outside the building.
Using Your Exhaust Fan Effectively
- Turn it on before you shower: Starting the fan before you turn on the water establishes airflow that helps capture steam as it's generated.
- Keep it running after: Leave the fan on for 15-20 minutes after you finish showering. This clears remaining humidity and helps surfaces dry.
- Close the door while running: A closed door with the fan running creates negative pressure that pulls air (and moisture) toward the exhaust vent.
When Your Exhaust Fan Isn't Enough
Some bathroom fans are undersized for the space or poorly maintained. Signs your fan isn't doing its job include:
- Mirrors stay foggy for a long time after showering
- Humidity doesn't noticeably decrease with the fan running
- The fan seems weak or makes unusual noises
- You can't feel air being pulled into the vent
If your fan seems inadequate, notify your landlord. Fans can lose efficiency due to dust buildup, motor problems, or blocked venting. A working exhaust fan is a reasonable expectation in rental housing.
Quick test: Hold a tissue near the exhaust vent with the fan running. It should be pulled toward the vent. If it isn't, the fan may not be working effectively.
Ventilation Without an Exhaust Fan
Some bathrooms, especially in older buildings, lack exhaust fans. In these cases, alternative ventilation becomes essential.
Open Windows
If your bathroom has a window, open it during and after showers. Even a small opening allows steam to escape. In cold weather, crack the window just enough to create some air exchange—you don't need it wide open.
Leave the Door Open
After showering, open the bathroom door to allow humid air to disperse into the larger apartment. This isn't ideal—you're spreading moisture rather than removing it—but it's better than trapping all the humidity in the bathroom. Combine this with opening windows elsewhere to create airflow.
Use a Portable Fan
Place a small fan in the doorway pointing outward to help move humid air out of the bathroom. Direct it toward an open window in an adjacent room if possible.
Shower Habits That Reduce Humidity
Small changes to how you shower can meaningfully reduce the moisture your bathroom deals with.
Shorter Showers
Less time under running water means less steam. A five-minute shower produces significantly less moisture than a fifteen-minute one.
Slightly Cooler Water
Very hot water produces more steam than warm water. You don't need to take cold showers, but dialing back the temperature a bit reduces humidity generation.
Squeegee Shower Walls
After showering, use a squeegee to wipe down glass doors and tile walls. This removes water that would otherwise evaporate into the air over the following hours.
Spread Out Shower Times
If multiple people share the bathroom, spacing out showers allows humidity to clear between uses. Back-to-back showers keep humidity continuously high.
Managing Wet Items
Towels
Wet towels continue releasing moisture until they dry. Spread towels out to dry rather than leaving them bunched. If possible, hang towels outside the bathroom or near a window. Replace towels regularly—they should dry within a day; if they don't, your bathroom may be too humid.
Bath Mats
Bath mats absorb water and hold it. Stand them up to dry after use rather than leaving them flat on the floor. Consider washable bath mats that can be laundered and dried completely.
Shower Curtains
Spread the shower curtain out after showering so air can circulate and help it dry. A bunched-up curtain stays wet longer and can develop odors or discoloration.
Surface Water
Wipe down wet surfaces after showering or bathing. The counter, sink, and toilet can all collect water. Wiping these surfaces prevents that water from evaporating into the air and adding to humidity.
Check around the toilet base, under the sink, and around faucets for slow leaks. Even minor drips add humidity over time and can indicate problems that need repair.
Bathrooms Without Windows
Interior bathrooms with no windows present the greatest challenge. They depend entirely on mechanical ventilation or air exchange with the rest of the apartment.
If you have a windowless bathroom with an inadequate exhaust fan:
- Keep the door open as much as practical
- Run a fan in the doorway after showers
- Consider a small moisture absorber for continuous passive drying
- Be diligent about wiping surfaces and spreading towels
- Request exhaust fan repair or improvement from your landlord
Preventing Moisture Spread
Bathroom humidity can migrate to adjacent rooms, affecting closets, bedrooms, and other spaces.
- Close adjacent doors: If the bathroom connects to a bedroom or closet, close those doors during and after showers to contain moisture.
- Ventilate toward the outside: Direct airflow toward windows or exterior vents, not toward bedrooms and closets.
- Address it at the source: The more effectively you remove humidity from the bathroom, the less spreads elsewhere.