In a forced air heating system with a humidifier, how is humidity typically reduced?

In a forced air heating system that includes a humidifier, humidity is typically reduced through the process of condensation at the evaporator coil. When air passes over the chilled surface of the evaporator coil, the temperature of the air drops, leading to the condensation of moisture from the air. This process effectively removes humidity from the air stream, thus helping to maintain comfortable indoor humidity levels during cooling operations.

The evaporator coil operates by absorbing heat from the air, which cools the air. As the air cools, its capacity to hold moisture decreases, and excess moisture condenses out of the air. This condensed moisture is then drained away, reducing the overall humidity in the living space.

In contrast, other options do not accurately describe the function of humidity reduction in forced air systems. For example, running the humidifier in reverse or relying on condensation directly occurring within the compressor or at the condenser coil does not align with the typical operation and mechanics of such heating and cooling systems.