What is an 'exhaust fan' used for in building ventilation?

The function of an exhaust fan in building ventilation is primarily to remove contaminated air from a space. These fans are designed to expel indoor air, which may contain pollutants, moisture, odors, or other unwanted elements, thus helping maintain indoor air quality. By facilitating the removal of stale or contaminated air, exhaust fans contribute to a healthier environment by ensuring that fresh outdoor air can enter the space in a balanced ventilation system.

In a typical application, for example, exhaust fans are often used in kitchens to eliminate smoke and kitchen odors or in bathrooms to reduce humidity and prevent mold growth. This process is essential for regulating air quality and ensuring the comfort of occupants in a building.

Other options do not accurately reflect the primary function of an exhaust fan. While distributing fresh air and cooling environments may be relevant to various ventilation mechanisms, they do not pertain specifically to exhaust fans, which focus solely on removing air from a space rather than circulating or introducing it. Additionally, while noise levels might be impacted by the operation of an exhaust fan, this is not its intended function and certainly does not summarize its role in building ventilation.