An exhaust fan is a mechanical ventilation device used to expel unwanted air, fumes, smoke, moisture, heat, and/or other indoor air pollutants from a room or building. It is typically installed in kitchens, bathrooms, garages, attics, and other spaces where moisture, heat, or fumes may accumulate. Exhaust fans can be wall-mounted or ceiling-mounted and come in a variety of sizes and capacities, depending on the specific application and environment. They use a motor to drive a fan that draws air out of the room and vents the buildup of unwanted indoor air pollutants.