By Christine G. Crocker, Executive Director, Maine Indoor Air Quality Council

HIGH HUMIDITY LEVELS in your home are a common culprit for moisture and mold problems.

Cooking, bathing, people, plants and pets are all sources of moisture that contribute to indoor humidity issues. When warm, humid air lands on a cool surface, the moisture in the air condenses into liquid water on the surface material. When the cool surface is your glass of iced tea, the glass gets wet. Likewise, when the cool surface is your basement, attic, or windowpanes, those surfaces get wet. Moist, damp conditions lead to mold and bacteria growth and increase the risk of insect and other pest problems.

MONITORING YOUR HUMIDITY IS EASY AND LOW-COST

You don’t need a high-end piece of equipment to monitor the humidity in your home. A quick browse through your local hardware store or online should provide you with plenty of options for $20 or less. Spend a little more, and you can find systems with multiple humidity monitors connected to a central unit (or connected via Wi-Fi to your phone), allowing you to track several problem areas of your home at the same time.

WHAT IS A HEALTHY HUMIDITY LEVEL?

Keeping your relative humidity (RH) at or below 60% will go a long way toward preventing moisture from condensing on cold surfaces in your home and causing problems. Measure your RH frequently, particularly in the summer months.

What to do if your humidity is consistently above 60%

1. Ventilate high moisture-generating areas (such as kitchens and bathrooms) using fans that exhaust outdoors. Because basements have a lot of cold surfaces, do not ventilate your basement in the summer months unless the air outdoors is cool and very dry.

2. Install a dehumidifier in spaces that consistently have a relative humidity level that is higher than 60%, especially your basement. Routinely monitor, clean and maintain your dehumidifier following the manufacturer’s instructions.

Tip: If dehumidifying a basement, consider purchasing a model designed for basement use. While more expensive, these dehumidifiers are designed to work in lower basement temperatures. They use less electricity, do a better job of drying humid basement air, and can be set up to drain automatically into a sump or sewer system.

For more information on preventing mold and moisture problems in your home, visit the website of the Maine Indoor Air Quality Council at maineindoorair.org.

This article appeared in the Fall 2022 edition of Green & Healthy Maine HOMES. Subscribe today!

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