Humidifier vs. Dehumidifier: Do You Need Both?

Most people don’t need both a humidifier and a dehumidifier running all the time. In most homes, you only need the device that corrects the current problem: either elevated moisture (dehumidification) or overly dry air (humidification). The key is measuring indoor humidity and matching the fix to real conditions.

Indoor humidity is typically measured as relative humidity (RH). Many indoor air-quality guidelines recommend maintaining RH around 30%–50%. When humidity drifts outside that range, comfort and air quality can suffer—and so can the building materials in some cases.