What is a potential problem with powered roof fans?

The correct response highlights one of the primary concerns associated with powered roof fans. These fans can indeed pull conditioned air from the living spaces of a home into the attic, leading to energy inefficiency. When the fan operates, it creates a negative pressure in the house, which can allow warm, conditioned air to escape, particularly in homes that are not sufficiently sealed. This not only wastes energy but can also drive up heating and cooling costs.

Additionally, while the other options touch on various aspects of ventilation systems, they do not encapsulate the core issue as effectively. For instance, powered roof fans can improve ventilation efficiency in some scenarios; however, this benefit may not outweigh the potential for losing conditioned air. Temperature imbalance is also a concern, but it is often a secondary effect resulting from the direct loss of conditioned air. Lastly, while fans can influence humidity levels under certain conditions, this is not as immediate or direct of a problem as sucking conditioned air out of the house.