Plumbing codes require bathrooms to contain an operable window, an exhaust fan, or both — for good reason. In an unventilated bathroom, warm, moisture-laden air can condense on cool wall and window surfaces, where it supports bacteria and mildew growth, causes paint failure, and may even lead to structural damage from decay, as it penetrates and condenses in wall cavities. The problem with the minimum code requirement is that no one wants to leave the bathroom window open year-round, and most exhaust fans are too noisy. Do your customer a favor by recommending a bathroom ventilation strategy that works: a quiet fan with enough exhaust capacity for the space, and controls that make it convenient to use. Effective Air Change The
