Dryer exhaust systems must be independent of all other systems and convey moisture and combustion products to which part of the building?

The correct choice is that dryer exhaust systems must convey moisture and combustion products to the outside of the building. This requirement is essential for safety and efficiency in dryer operation.

When clothes are dried in a dryer, they release a significant amount of moisture. If this moisture is not vented outside, it could lead to excessive humidity levels within the building, promoting mold growth and potentially damaging the structure and indoor air quality. Additionally, proper ventilation helps to prevent the accumulation of lint and other flammable materials, reducing the risk of fire.

Furthermore, directing the exhaust outside ensures that any combustion products associated with gas dryers are expelled from the living space, mitigating safety hazards that arise from carbon monoxide and other harmful gases.

Other locations, such as the basement, attic, or interior of the building, would not effectively address these concerns, as they could allow moist air or combustion products to circulate back into the habitable areas, leading to various health and safety issues. Thus, venting to the outside is the only appropriate choice for the dryer exhaust systems.