This accelerated evaporation rate will usually cause the relative humidity to increase. Evaporation stops when the air is saturated and cannot hold any more moisture. Air movement created by installing air movers on the wet surface circulates the saturated air on the material's surface to the top of the room where it is slightly warmed. Then the warm moist air is circulated downward, where it comes in contact with a cooler surface, i.e. carpet fibers. As a result, condensation occurs and the moisture just removed from the carpet can be put right back into the air space.
Condensation is the change of water vapor to a liquid.
This reduction in relative humidity will last for a short time, until evaporating moisture from the carpet, carpet cushion, and other building materials causes the air to reach the saturation point again. This secondary exposure results in moisture absorption into materials such as, drywall, paper, paneling, wallpaper, veneer on furniture or cabinets, natural fiber fabrics, latex paint, and eventually framing materials. The result is discoloration, delamination, swelling, warping, splitting, and microorganism growth. Dehumidification is a vital part of the process as we work to reduce the moisture content of the air. Dehumidifiers are installed to keep the air from reaching its saturation point and to prevent further damage from condensation.