Which kind of air does the exhaust duct primarily handle?

The primary function of an exhaust duct is to remove stale air from areas such as kitchens and bathrooms. These areas generate humidity, odors, and potentially harmful contaminants, making it essential to vent this air outside. Properly designed exhaust systems ensure that these pollutants are expelled, thus maintaining indoor air quality and comfort.

In the context of kitchen environments, exhaust ducts effectively handle smoke, grease, and cooking odors, while in bathrooms, they efficiently remove moisture-laden air, preventing the growth of mold and mildew. This makes the management of stale air critical for both hygiene reasons and overall living conditions. The other types of air mentioned, like fresh air, conditioned air, and recirculated air, do not pertain to the primary function of exhaust ducts, as they do not focus on the removal of air contaminants and humidity from specific areas.