Turn on the ceiling fans. Keeping the air moving is an essential part of keeping excessive moisture away. Using ceiling fans, pedestal fans and other air-moving appliances can make a big difference and suck excess moisture out of the indoor air. Check the exhaust fans in your attic, kitchen and bathroom.
Once you are done cooking or showering, be sure to run your exhaust fans for at least 5 minutes to prevent the buildup of moisture in your home. It's important to note that although they can be extremely helpful, running these fans for too long can actually bring in more humidity than it gets rid of.
Turn off certain appliances (such as humidifiers or kerosene heaters) if you notice moisture on windows and other surfaces. Use dehumidifiers and air conditioners, especially in hot, humid climates, to reduce moisture in the air, but be sure that the appliances themselves don't become sources of biological pollutants.
Lowering the fan speed is one way to control a large amount of interior humidity. A colder evaporator coil can remove more moisture from the air, but it is important that the evaporator coil doesn't freeze.
Open the windows to ventilate the inside of your home.
Opening multiple windows will allow a cross breeze to develop in your home, which will help more humid air to circulate out. You don't need to open your windows all the way; just crack them 1 to 2 inches (2.5 to 5.1 cm).
Using Air Conditioner to Reduce Humidity
In the summer when the outside temperature is high, and humidity rises, use your air conditioner humidity setting (setting your AC to cooling mode) to reduce your home's overall temperature and encourage humidity levels to drop.
Get a Dehumidifier
The most surefire way to reduce indoor humidity is to get a dehumidifier. Dehumidifiers fit right inside your furnace air handler, and removes moisture from the air as it passes through.
Do you feel like you're never comfortable at home, even though the AC reaches the set temperature? Your home's humidity level may be too high. A home should have a relative humidity of 30% to 60%. Above 60% and you have what's considered “high” humidity.
High humidity in a house can be caused by many things, but the biggest reason is poor ventilation—in other words, air isn't being circulated properly, which causes the air in your house to become stagnant and humid. The other major reason? Too much air exchange with the outside.
Most people enjoy the cooling and comfortable breeze of a fan. But excess wind makes the air dry. When you sleep, this dry air may affect your breathing, causing sleep disruptions. Using a fan at night can even aggravate your allergies, making you uncomfortable throughout the night.
Use a Dehumidifier and a Fan
If you don't have AC or it's not powerful enough, Weiss suggests placing a bowl with cold water and ice in your bedroom. Position a fan behind it and facing toward your sleeping space to amplify the fan's cooling effects.
Let's talk about what humidity levels you should keep in your home year-round, and different techniques to do so. Ideal in-home humidity levels should hover around 45%. Anything under 30% is too dry, and over 50% is too high.
High humidity is associated with increased nighttime sweating. Because mold and dust mites thrive in humid environments, these nighttime allergens are more common in bedrooms with more moisture. As a result, sleepers may experience increased allergy or asthma symptoms.
The Health and Safety Executive recommends that relative humidity indoors should be maintained at 40-70%, while other experts recommend that the range should be 30-60%.
An indoor humidity level is too high when it's above 50%. At this level, your home is susceptible to increased dust mite infestations, as well as mildew, mold growth, and other bacteria. This can cause serious health issues for those who breathe in mold spores or are exposed to bacteria for long periods of time.
Water Vapor
If there are no cold-condensing surfaces and the relative humidity (RH) is maintained below 60 percent indoors, there will not be enough water in those materials for mold to grow. However, if the RH stays above 70 percent indoors for extended periods of time, mold will almost certainly grow.
Baking Soda as a Moisture Absorber
Remove dampness by filling a small bowl with baking soda and placing it in the room you'd like to dehumidify. Although it's not as effective as rock salt in combating humidity, it's good for enclosed spaces where moisture is an issue.
Rock Salt. The most popular DIY dehumidifier is the one that works the best—rock salt. Rock salt naturally absorbs moisture out of the air, making it a great choice to use as a dehumidifier.
One of the most common causes of high humidity levels is the buildup of dirt and other debris within the AC unit's air filter. If the air filters are dirty and covered in debris, your AC system will not function properly.
But when humidity levels spike, however, most systems can't cope. High humidity cancels out the air conditioner's cooling effect. When the humidity is too high, your building will feel warmer than it is. You may find yourself running the air conditioner harder for longer and not getting the desired effects.
Will the humidity rise if the heat is turned up? Contrary to popular belief, heating the air actually lowers the relative humidity. This is because, as the temperature of the air increases, the air can hold more molecules, and its relative humidity goes down.
Research shows that the ideal relative humidity for your home is between 40%-60%. However, to discourage the growth and spread of mold, levels should be kept below 50%. But, again, adjust this to match your comfort levels. This relative humidity in your home should also scale with the outdoor absolute humidity.
Since our bodies release over half a liter of fluid at night, the humidity in the room also increases while we sleep. Especially during the summer months, the indoor climate can quickly become unstable because the more the air warms up, the more moisture it can absorb.
The ideal relative humidity for health and comfort is somewhere between 30-50% humidity, according to the Mayo Clinic.