Relative humidity (RH) is the percentage of water vapor in the air at the current temperature. The Environmental Protection Agency advises 30% RH as the safe minimum. Many sleep and other health experts suggest 40% for most people. That can be difficult to achieve without the help of a whole-house dehumidifier in Keizer, OR. Woodward Heating Air Plumbing can install a dehumidifier to set your ideal RH precisely.