What is the recommended indoor humidity level for homes?

The recommended indoor humidity level for homes typically ranges from 30 to 50% relative humidity (RH). Maintaining humidity within this range is essential for comfort, health, and energy efficiency.

When indoor humidity is kept between 30 to 50% RH, it helps prevent the growth of mold and mildew, which thrive in more humid environments. This range also helps to minimize respiratory problems and reduce the likelihood of dust mites, which can cause allergies. Furthermore, proper humidity levels can enhance energy efficiency, as overly humid air can make spaces feel warmer and lead to increased use of air conditioning.

While the option of 40 to 60% RH does encompass the recommended range, it is slightly broader. The optimal recommendation leans more firmly towards the 30 to 50% range, as it ensures conditions are suitable for both health and energy conservation, while being mindful of potential moisture-related problems. Therefore, option B, while acceptable in many contexts, does not align precisely with the most ideal recommendation for indoor humidity.