How much humidity is too much in a basement

Indoor relative humidity (RH) should be kept below 60 percent — ideally between 30 percent and 50 percent, if possible. … Low humidity may also discourage pests (such as cockroaches) and dust mites.

Normal Basement Humidity Levels

When your basement is too humid, you’ll probably be able to feel it. A comfortable basement should maintain a humidity level of 30 to 50 percent — however, those may differ depending on your climate.

A relative humidity level of 70 percent or higher creates the perfect breeding ground for mold growth. Leaving basement mold unchecked could amount to unhealthy indoor air, causing sickness to your family and aggravated upper respiratory issues.

Dehumidify your basement

Mold and mildew flourish when the relative humidity level is above 80%; therefore all basements—finished or unfinished—should be kept at or below 50% relative humidity. In order to maintain that humidity level, May suggests using a dehumidifier and measure the humidity level often.

A relative humidity greater than 55 percent is enough to support the growth of black mold. … Household problems such as water and pipe leaks cause water intrusion and an environment perfect for black mold to grow. The mold can continue to grow unabated if a small leak goes undetected for a long time.

Should a Dehumidifier Run Constantly? No, there is no need to keep the dehumidifier running constantly. It’s generally enough to run the unit when the humidity level is 50% or higher. A good rule of thumb to remember is to maintain a comfortable 30-50% humidity level for most homes.

The Basement Health Association warns that relative humidity levels above 80 percent in basements causes mold and mildew to develop. Using a basement dehumidifier to keep humidity levels below 50 percent can prevent mold and mildew growth, protecting indoor air quality and preventing damage.

Although not normally a problem in a basement, air that is too dry can be adjusted with a space humidifier.

In conclusion, the best place to keep a dehumidifier most definitely is the downstairs basement or upstairs close to the stairs. This is because the basement is the most humid place in your house. If there is any other moist condition upstairs, its source must be resolved rather than placing a dehumidifier.

But humidity in the basement or crawl space affects the upstairs too. Since air flows into the upper levels of your home from the basement or crawl space, it brings the humidity from down there with it.

Con: Noise and Heat

Dehumidifiers also tend to blow warm air out of the back of the unit. In the winter, this can be an advantage — but not so much in the summer. Position the back of your dehumidifier in a doorway so that it doesn’t heat up the room from which you are removing excess moisture.

Many basements in warm humid climates need dehumidification during the summer months to keep mold growth at bay. If you notice a musty smell or odor in a room, it will probably benefit from a dehumidifier, as drier air is not only healthier for you but will also be less likely to smell or have a stale, musty odor.

A basement dehumidifier designed to work in low temperatures with proper square-foot and pint rating can work for your entire home. Whole-house dehumidifiers can also be professionally attached to an HVAC system to help keep the humidity at optimal levels in your entire home.

It is to set your dehumidifier to 50 percent to make sure the basement humidity level in summer is not too low or too high. It may be a little difficult to reach 50%, but with the right device, you will surely get at this number. You may think 50% is a safe number but you can’t risk your basement from possible damages.

For now, we leave you with this simple one: use a dehumidifier during the spring, summer and early fall to keep moisture at bay, but unplug and stow it away during the winter to prevent damage to your unit.

For a very damp basement or other space, it might be necessary to increase the size of the dehumidifier to efficiently remove the increased level of moisture from the air. Choose a dehumidifier that holds 12 pints of water for a 500-square-foot space, adding 5 pints for every additional 500 square feet.

Your standard dehumidifier will remove the moisture from the air in your home, but the size you need depends upon the size of the space in question. … A model that’s too small for your space may hardly make a dent in the moist air, while one that’s too large may make the air excessively dry.

Without a dehumidifier, it can take walls, carpeting, and other materials days or even weeks to dry. During that time, they can fall apart or even allow mold to grow. Once you remove the water, you need to dry water damage with a dehumidifier.