Analysis of indoor humidity levels suggests that more than 36% of US households have above EPA’s maximum recommended (above 60%) humidity levels. In the summer, houses without a whole-house dehumidifier can reach above 80% moisture levels. Basements and crawl spaces, for example, are especially humid; with relative humidity levels above 90%.

Without a whole house dehumidifier, high humidity in your house presents a potential danger on several fronts. Uncontrolled humidity and moisture can affect:

• People. Kauvery Hospital points out that respiratory allergies like asthma, nasal problems, unnatural growth of dust mites, allergic rhinitis could be affected by high indoor humidity levels. Summer of 2019, for example, was one of the worst ones to date as far as humidity levels are concerned.
• Mold and mildew growth. High humidity levels are ideal conditioners for mold growth. Given how difficult is to get rid of mold once it infests your house, using a whole-house dehumidifier to lower humidity levels below 50% is the most useful proactive way to prevent mold and mildew growth.
• Structural damage. Prolonged high humidity levels – especially in the basement – can eat through and crumble the walls (moisture-induced corrosion, reinforced concrete rusting). If structural walls are subjected to 80%+ humidity levels, your whole house’s structure might be in danger; this heavily reduces the home value.