Exhaust ducts can rightly be vented into the attic.

Venting exhaust ducts into the attic is not recommended for several reasons, making the assertion that they can rightly be vented there false. Exhaust ducts, which carry moisture-laden air from bathrooms, kitchens, or laundry rooms, can introduce excess humidity into the attic space. This humidity can lead to various issues, such as mold growth, deterioration of building materials, and potential structural damage over time. Moreover, allowing exhaust air to enter the attic can create pressure imbalances, resulting in the potential for unconditioned air to enter the living space, compromising indoor air quality and energy efficiency.

In general, exhaust systems should be vented directly to the outdoors to ensure that moist, warm air is properly expelled and does not accumulate in enclosed spaces like attics. Proper venting helps maintain a healthy indoor environment and safeguards the integrity of the building envelope.