Definition
Relative humidity (RH) is the amount of water vapor in the air compared with the most that air can hold at its current temperature, expressed as a percentage. Warmer air holds more moisture, so RH rises as air cools. EPA recommends keeping indoor relative humidity below 60 percent, ideally between 30 and 50 percent.
Also called: RH, Indoor humidity
Why it matters to you.
Central Kentucky summers push indoor humidity up, and sustained high humidity feels clammy, encourages dust mites and mold, and can leave basements and crawlspaces musty. In winter, heated indoor air can swing the other way and feel dry during cold snaps.
Practical guidance.
Homeowners can measure RH with an inexpensive hygrometer in a few rooms and keep bath and kitchen exhaust fans working. If summer readings stay high, a technician can check air conditioner sizing, airflow and coil condition before recommending dehumidification.
About this definition
Written by the Feistritzer Heating & Air Conditioning team — family owned and operated in Danville since 1976, Kentucky HVAC license M02584. Definitions inform; a whole-system diagnosis in your home decides.