What is the recommended indoor relative humidity level for residential spaces during the summer?

The recommended indoor relative humidity level for residential spaces during summer is around 50%. This level of humidity strikes a balance between comfort and preventing potential issues associated with excessive moisture, such as mold growth and dust mites. When humidity levels exceed 50%, the air can feel sticky and uncomfortable, leading to increased reliance on air conditioning systems. Maintaining indoor humidity at this level can improve comfort, protect structures and furnishings from damage, and promote better indoor air quality. Keeping humidity at or below this recommended level supports the efficiency of cooling systems, ensuring they operate effectively without excessive strain.