Humidity can make indoor spaces feel hot, stuffy, and uncomfortable. High humidity encourages the growth of mold, mildew, dust mites, and bacteria. It can also damage furnishings and electronics. There are several effective strategies to lower humidity in a room and create a healthier, more comfortable environment.
Use a Dehumidifier
A dehumidifier is the most direct way to actively reduce humidity. It draws moist air into the unit, condenses the water vapor by cooling the air, then releases dry air back into the room. Look for a dehumidifier that allows you to set your desired humidity level. A hygrometer can help monitor the humidity.
Place the dehumidifier in a central location in the problem room, leaving adequate space around it for air circulation. Empty the water reservoir regularly so the unit runs efficiently. Supplement with other humidity-lowering tactics for the best results.
Improve Air Circulation
Stagnant air allows humidity to build up. Improve circulation by opening windows regularly to allow fresh dry air to enter and moist air to escape. Using fans will keep air moving and prevent pockets of high humidity from forming.
Aim box or oscillating fans out open windows or doors to push moist indoor air out. Place free-standing or ceiling fans inside the room to keep the air moving. Make sure furniture, curtains, or other objects do not block airflow from fans or ventilation ducts.
Add Houseplants
Certain houseplants act as natural humidifiers by absorbing moisture through their leaves and releasing it into the air. Having a few low-maintenance, humidity-loving plants like aloe vera, ferns, or philodendrons can help lower humidity levels without constantly running a dehumidifier.
Group plants together rather than spreading them out for the best dehumidifying effect. Just be sure not to overwater them or place them in direct sunlight, as this causes excess moisture release.
Use Desiccant Dehumidifiers
Desiccant dehumidifiers (also called absorptive or dessicative dehumidifiers) use materials like silica gel, zeolite, or calcium chloride instead of a compressor to absorb moisture. They are ideal for humid climates or spaces under 1,000 square feet.
Look for rechargeable desiccant units where the drying agent can be ‘renewed’ by heating it to release moisture, allowing repeated use. Place desiccants out of reach in closets, on shelves, or other out-of-the-way spots to work passively at reducing humidity.
Cook, Clean, and Bathe Less
Simple lifestyle adjustments can make a noticeable difference in indoor humidity levels. Cooking, cleaning, bathing, washing clothes and dishes, and any other indoor water use adds moisture to the air.
Run exhaust fans while cooking and showering. Limit major cleaning or laundry to cool, sunny days when you can open windows. Run large appliances like the dishwasher at night so moisture has time to dissipate before closing the home up in the morning.
Use a Humidistat
A humidistat is a humidistat switch that turns on a fan, dehumidifier, or A/C unit when humidity rises to undesirable levels. Use a humidistat to automate humidity control rather than manually operating devices as needed.
Humidistats can be standalone devices or incorporated into other equipment like a dehumidifier or HVAC system. Place the sensor in a central spot away from windows, doors, and vents for accurate readings. Adjust the setting to your desired humidity level.
Absorb Moisture
Specialized moisture-absorbing products can passively soak up humidity. DampRid and similar products contain calcium chloride or other hygroscopic compounds. Place moisture absorbers in closets, under sinks, or anywhere prone to excess moisture.
Replace them regularly according to package directions as they fill with water. Use them to supplement active dehumidification, not as a standalone solution. Rice, salt, or silica gel packs can also be reused to absorb moisture if dried out in the oven every few days.
Run an Air Conditioner
Air conditioners reduce humidity as a byproduct of cooling the air. Overcooling can save energy compared to running a separate dehumidifier.
Make sure the A/C unit is properly sized for the space. Set the temperature lower than normal, around 68-70°F to offset the added humidity. Draw in drier air by running the A/C with the fan setting on rather than auto.
Use a Vapor Barrier
In cases of persistently high humidity, moisture may be moving through ceilings, walls, and floors from crawlspaces, attics, or even the ground. A vapor barrier such as primer, paint, or polyethylene sheets blocks this moisture transfer.
Apply vapor barriers to interior surfaces where moisture passes through. Ensure crawlspaces and attics have proper ventilation to allow moisture to escape rather than permeate into living spaces. Vapor barriers help control extreme humidity only after addressing any leaks or insulation issues first.
Maintain Proper Ventilation
Ventilation allows fresh, dry air to enter and replaces moist indoor air. Ensure bathrooms, laundry rooms, kitchens, and any other humid areas have working exhaust fans that vent outside. Run these fans regularly, especially during and after activities that release moisture.
Likewise, make sure dryer vents, stove vents, and HVAC systems are properly installed and functional. Repair any leaks, gaps, or clogs that allow outdoor air and moisture in unintentionally. Proper ventilation regulates indoor humidity.
Frequently Asked Questions
What is a comfortable humidity level for indoor air?
Between 30-50% relative humidity is recommended for indoor comfort and health. Below 30% is uncomfortably dry for most people. Above 50% encourages mold, mildew, and dust mite growth.
What causes high humidity indoors?
Cooking, bathing, washing clothes and dishes, houseplants, outdoor humidity, poor ventilation, moisture intrusion through walls and floors, and malfunctioning HVAC systems all contribute to indoor moisture buildup.
Will a dehumidifier cool the room’s temperature too?
A dehumidifier only reduces moisture, not temperature. Many have built-in humidistats to prevent over-drying. An air conditioner lowers both temperature and humidity. A dehumidifier used with an air conditioner balances both for maximum comfort.
When is indoor humidity most likely to be high?
Humidity tends to spike in the warmer months of summer. It can also climb after bathing, cooking, cleaning, or using appliances that release steam or moisture indoors, even in winter.
How long does it take a dehumidifier to work?
A properly sized dehumidifier will begin lowering humidity levels within 30 minutes to an hour. Larger capacity units work faster than small ones. Running it continuously rather than intermittently works best.
Can I lower humidity without a dehumidifier?
Yes, running fans to improve airflow, adding houseplants, using moisture absorbers, running A/C, and improving ventilation will help reduce humidity without a dehumidifier unit. However, a dehumidifier works most quickly and efficiently.
Conclusion
Excessively high humidity makes indoor living uncomfortable while contributing to mold, mildew, and dust mite growth. Take steps to lower humidity using dehumidifiers, fans, houseplants, airflow improvements, vapor barriers, A/C adjustments, and moisture control habits. For optimal comfort aim to keep relative humidity around 30-50%. Monitor humidity levels and take action promptly when they rise too high indoors. With diligent moisture control, you can enjoy cleaner air and a healthier living space.