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InsightHorizon Digest

What should the humidity be in a basement in the summer

Author

William Taylor

Updated on April 23, 2026

That air can make its way into your basement, increasing your humidity levels to around 60 percent. Because of this, homeowners must work to adjust those levels back to the ideal humidity level between 30 and 50 percent or risk mold, mildew and bacteria buildup.

What should basement dehumidifier be set at in summer?

The ideal relative humidity level should be somewhere between 30% – 50%. Many basements in warm humid climates need dehumidification during the summer months to keep mold growth at bay.

What humidity level should you keep your basement at?

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.

Is 70 humidity too high for basement?

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.

Will mold grow at 55 humidity?

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.

At what temperature should dehumidifier be set in summer?

Residential dehumidifiers use refrigerant and a condenser to remove moisture from the air. They work best in temperatures above 60 degrees F.

Should I run dehumidifier in basement in summer?

Do you need to run a dehumidifier in basement during winter and summer? Regardless of the season, if the relative humidity is higher than the recommended level of 60%, you should run a dehumidifier. … In a better perspective, winter generally has colder and drier air than in summer.

When should you turn off dehumidifier in basement?

If the temperature or humidity drops below the ideal level, you will want to turn the dehumidifier off. You never want the coils or water to freeze because it can cause lasting damage to the device.

Is 60% humidity in basement too high?

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.

Should I use dehumidifier in summer or winter?

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.

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Should you run a basement dehumidifier in the winter?

You should only run a dehumidifier in your basement in the wintertime if the room maintains a high relative humidity. To monitor the relative humidity in your basement, hang a humidistat (sometimes called a hygrometer) on the wall. It works like a thermometer, constantly measuring the relative humidity in the room.

What kind of dehumidifier do I need for basement?

30-Pint Dehumidifier – This is the size recommended for areas up to 1500 square feet, regardless of how damp the area is. That means it will be appropriate for most residential basements.

How can I lower the humidity in my basement?

  1. Open the Windows. A great way to get air circulating in the room is to open up the windows whenever you’re down there. …
  2. Keep It Clean! Storing too many items in your basement will create clutter. …
  3. Seal Up Any Gaps. …
  4. Turn Up the Heat. …
  5. Get a Dehumidifier.

Where should dehumidifier be placed in basement?

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.

Do dehumidifiers use a lot of electricity?

Dehumidifier energy use is rather low. An average small 30-pint dehumidifier uses 300W of energy. … Essentially, a dehumidifier draws much less electricity than a water heater, an air conditioner, even a hair drier. An average dehumidifier draws about as much energy as a computer.

What mode should I put my dehumidifier on?

Ideally, that should equate to a dehumidifier humidity setting of around 40%, but you may wish to adjust it up or down to find the humidity level that feels most comfortable for your space and your household.

Will a fan in the basement help reduce humidity?

A fan itself won’t really help with the humidity levels in your cellar, but it will help with getting air moving into the room from other areas such as the rest of the house and outdoors. Having a fan on a low speed regularly in your basement will improve airflow – thus moving the wet air out and the dry air in!

Should I run a dehumidifier in the summer?

Running a dehumidifier in the summer months is one way to improve indoor air quality and help lower the occurrence of allergy symptoms and asthma attacks. By removing excess moisture from the home’s air supply, whole house dehumidifiers help reduce allergens such as mildew and mold growth in the home environment.

Is a 50-pint dehumidifier enough for basement?

40 to 50-Pint Dehumidifiers They are ideal for a damp basement or room, with clear indications of excess moisture, such as visible mold growth, damp stains, and musty odors.

Do you need a dehumidifier in the basement if you have air conditioning?

Air conditioners do have some dehumidifying function, though it’s entirely accidental. The system cools the air past the dew point, which causes it to shed some of its extra humidity. … If you want to avoid the issues associated with high humidity, you should absolutely install a dedicated dehumidifier in your home.

How big of a dehumidifier do you need for a basement?

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.

Does opening basement windows help humidity?

To prevent basement dampness the last thing you want to do is open the windows down there. Summertime air is humid. Open windows let that warm, damp air inside. … When warm, humid air comes into contact with those cold materials, moisture contained in the air condenses out.

Why does a basement have high relative humidity in the summer?

How Humid Air Causes More Basement Moisture in the Summertime. … Air humidity is greater in the summertime simply because warm air is able to hold more moisture than cold air. This humid indoor air increases the risk of basement water damage because a lot of finished basements use drywall.

How do I dehumidify my basement without a dehumidifier?

  1. Airflow to reduce humidity.
  2. Crystal salt as a desiccant to absorb moisture.
  3. Charcoal as a desiccant to absorb moisture.
  4. Install the fan and proper ventilation.
  5. Place dry clothes outdoors (in the sun)
  6. Always have the air conditioning on.
  7. Cool shower.

Do I need 2 dehumidifiers?

Commonly, you might need one dehumidifier per area, but you can also get one single dehumidifier for the whole house. However, keep in mind that doing that would cost you more money and be installed by a professional.