Which of the following factors is NOT a consideration in ventilation systems?

In ventilation systems, humidity control is indeed an important consideration; however, the question asks for a factor that is NOT typically highlighted as a primary consideration.

Airflow rates are critical because they determine how effectively air is exchanged in a space, impacting both indoor air quality and comfort. Energy efficiency is also a key factor, as it relates to the operational costs of the ventilation system and its overall impact on energy consumption. Noise levels are significant as well, since excessive noise from ventilation systems can lead to discomfort and reduced productivity in various settings.

Humidity control is certainly a factor that can play a role in overall comfort and health, particularly in specific environments like kitchens or bathrooms, but within the context of ventilation systems, it is often managed indirectly through other means. Overall, while it may be an important aspect of a comprehensive HVAC strategy, it doesn't typically fall under the core considerations that define ventilation system design and operation in most general discussions.