Indoor Relative Humidity

Relative Humidity
If it's an 80-degree day with Relative Humidity of 80%, and we suck this air into our basements and cool it to 68 degrees, the Relative Humidity goes up by 26.4% (12 degrees x 2.2%). But wait a minute, 80% plus 26.4% is more than 100%, and we can't have more than 100%. So instead, as the air becomes saturated, it gives up its moisture on your cold basement or crawl space walls, floor, water tank, pipes, and other cold things. This is called condensation.

Even without condensation, we still get high relative humidity levels, which allow mold and mildew to grow and cause "stinky basement syndrome." And dust mites thrive as well (More on dust mites later).

In order to eliminate condensation you need to either heat the air (ridiculous in summer), or take water out of it (easy to do). Correction. I should say take water out of it efficiently and effectively (not so easy unless you have the right equipment to do it with).