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Baby, it’s cold outside!!

snowy building in the winter time

During this time of year, I love to hear the old song “Baby, it’s cold outside!” play on the radio.  It sums up winter time in the Chicago area.  And with this frigid weather, we retreat to the comfort and warmth of our homes.  

But the warmth that we feel inside our homes can bring hidden dangers that can spell “M-O-L-D”.  Now, how can this be?  We usually associate mold with summertime flooding or a leaking pipe.  How can mold develop in the absence of a major water event?  I can answer that in one word – “Humidity”.  

Mold needs moisture more than anything else in order to survive and grow.  On days when we experience extreme cold outdoors, it is possible to have humid indoor air (humidity is a form of moisture) hit a super cold surface, like a window, and create condensation.  This moisture can roll down a window pane and lead to mold on the window sill, or worse, in the wall below.

What’s the best way to prevent this mold growth?  We recommend that during periods of extreme cold, make sure your indoor humidity level is reduced.  A handy gadget to help you monitor the level of humidity indoors is a hygrometer.  Some professional organizations recommend that your humidity level should be below 60 percent, but I would recommend continuing to reduce the humidity level until you no longer have condensation on the windows. You may need to keep humidity down below 20% to prevent condensation on some inefficient windows. 

If you see condensation on windows, we recommend turning down your humidifier, or turning it all the way off if that is the only way to keep windows dry.  Be sure to always operate your bathroom exhaust fan when showering and kitchen exhaust when cooking (if you have one that exhausts to the outdoors).  Only on rare occasion would you need to operate a dehumidifier during the winter time; it’s better to catch the moisture at the source.  
“Baby, it’s cold outside”, but you can still be comfortable and mold free inside your home.

Scott Wieringa

Scott Wieringa

Scott Wieringa is a Project Manager that performs indoor air quality assessments with a specialty in radon and odors. Mr. Wieringa holds a Bachelor of Arts degree from Calvin College. He is an ACAC Council-Certified Indoor Environmentalist (CIE) and Illinois Licensed Radon Professional with residential and commercial building endorsements. Prior to working at Indoor Science, Scott was a residential real estate appraiser with over 23 years of experience inspecting properties in varying capacities. In his words… “I have a special interest in helping clients track down how their homes or businesses might be making them sick. In my spare time, I’m involved in songwriting, sketching, and spending time with my family.”

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