Preferred Air, Inc. 239-354-5333

Relative humidity is expressed as a measure of the amount of water vapor the air contains as a percentage of the total amount it could contain at a specific temperature. If you think of air as a sponge for a moment, it can only hold a specific amount of water at a specific temperature. However, unlike a sponge, the total amount of moisture the air can hold changes as the temperature changes. As the air becomes warmer, it can hold a greater mass of moisture.

Consider this example of how the relative humidity changes as temperature changes with indoor air at 75°F and 60% RH. If this air cools down (not from an air conditioner) to 70°F, the air can no longer hold as much moisture, however the actual amount in the air has not changed, so the relative humidity increases to about 70%.