Determining if You Have a Humidity Problem in Your Home

October 27, 2015

Excess humidity in your home can cause a number of problems: a clammy, uncomfortable feeling; water stains on walls and ceilings; rotting window sills; a musty odor; and mold. There are a number of ways to deal with these problems, but first you'll need to determine your home's relative humidity.

Relative Humidity Your home's relative humidity should ideally be between 30 and 50 percent. In general, humidity will be in the lower range during the winter and higher in the summer. You can purchase an inexpensive device called a hygrometer from a home improvement store to test the humidity.

Too Much Humidity Regardless of the season, some homes can have too much humidity. The cause can be anything from roof or plumbing leaks to taking prolonged showers, a clogged condensate drain or inadequate ventilation. You know your home is too humid in the winter when you see excessive condensation on the windows. This happens when windows cooled by low outside temperatures encounter warm, moist interior conditions. Condensation can drip onto window sills and down walls, causing wood rot, water stains and other problems. Condensation can also occur in the attic from an improperly vented exhaust fan or inadequate insulation on the attic floor. In summer, humidity exceeding 50 percent can make a home's occupants feel too warm. The aforementioned problems of mold, musty odors and water stains will also occur.

Solutions Once you determine the source of excess moisture in your home, you can take steps to lower humidity. Here are a few suggestions:

  • Take shorter showers.
  • Fix plumbing and roof leaks.
  • Install attic insulation to prevent moisture. Likewise, fix any cracks or gaps in the attic.
  • Fix ductwork leaks.
  • Caulk around windows; add insulation around doors to prevent moisture infiltration.
  • Install exhaust ventilation in bathrooms and kitchens.
  • Install a dehumidifier.
  • Clear obstructions in the HVAC condensate drain.
  • Keep the coils on your HVAC system clean.
For more on determining if you have a humidity problem, contact Lozier Heating and Cooling of Des Moines. We've served the heating and cooling needs of Central Iowa for more than a century. Our goal is to help educate our customers in the greater Des Moines, Iowa area about energy and home comfort issues (specific to HVAC systems). Credit/Copyright Attribution: "Mario7/Shutterstock"