Humidity in your home – Know it and Control It | Volunteer Mold and Indoor Air Quality
About | FAQ | Blog
Call Now! 865-385-0170
Call Now! 865-385-0170

Humidity in your home – Know it and Control It

How much moisture in a home is “normal”?

The answer is different in every home.  Moisture is generated by multiple factors such as:

  • Home many people live in the home?
  • How much cooking, like boiling pots and baking, is being done?
  • How “tight” is the home?  Outdoor to indoor air exchanges.
  • Is the home a year old or 60 years old or somewhere in between?

 Moisture levels can be expressed and measured in terms of humidity.  Some moisture is a good thing.  Too dry and the occupants will notice abnormally dry skin and irritated nose or throats.  Too much dampness and the home will likely feel stuffy and or warm even though the thermostat is set to a nice cool temperature.  Most people feel comfortable with a humidity level between 40 and 45%.

 Too much humidity can set a home up for mold and bacteria growths.  Humidity levels in excess of 50% and ranging upwards for even a day or two is a great environment for microbial growths that can make a home unhealthy.

 Ever heard of the term relative humidity?  ­Relative humidity is the ratio of the current absolute humidity to the highest possible absolute humidity.  This level depends on the air temperature when you measure it.  A reading of 100 percent relative humidity means that the air is totally saturated with water vapor and cannot hold any more, creatin­g the possibility of rain.  As Home and Mold Inspectors we have seen it “raining” inside of homes and in crawl space and basement foundations.  

­People are very sensitive to humidity.  Our skin relies on the air to get rid of moisture. Sweating is our body’s attempt to keep cool and maintain its current temperature. If the air is at 100-percent relative humidity, sweat will not evaporate into the air. As a result, we feel much hotter than the actual temperature when the relative humidity is high. If the relative humidity is low, we can feel much cooler than the actual temperature because our sweat evaporates easily, cooling ­us off. Too much humidity at a higher temperature (like when we heat our homes) can actually make our bodies feel much warmer.  Too much humidity at a warm temperature (like when we are cooling our homes) can make us feel colder than the thermostat would lead us to believe.  See the chart below to see how temperature is affected by humidity.

How can a homeowner measure Humidity?

Many “Big Box” stores like Home Depot and Lowes sell Humidistats that you can hang on the wall of your home to allow you to monitor the humidity levels in your home.  Buy one.  Remember your target comfort zone will be 40 to 45 % Relative Humidity.

How can you control Humidity?

Simple things you can incorporate into your life style and your families’ use of the home can help.

  • Open windows to let dryer exterior air in when temperatures outside are comfortable.
  • Run the bath exhaust fans during and for thirty minutes after bathing or showering.  No exhaust fan in your bathroom?  Crack open the window a bit to allow moist air to exit.
  • Run the kitchen powered exhaust vent to draw out excess moisture when cooking or boiling foods in water.
  • Install a portable dehumidifier with a humidistat switch to help lower levels and control comfort for family members during periods of high humidity.
  • Use a humidifier to raise moisture levels when exterior temperatures dip below freezing for more than a few days.  All that cold air sucks the moisture out of the air. 

Many times you’re heating and Air Conditioning system will help regulate humidity levels.  That’s what “Air Conditioning” really means after all!

Call us or visit our web sites for more information on controlling Mold and Humidity levels in your home.  We will be glad to help!

Call us at (865) 385-0170 or visit us at  or

Tags: , , , , , , , , , , ,

Leave a Reply

This site uses Akismet to reduce spam. Learn how your comment data is processed.