What major influence does humidity have on air conditioning performance?

Humidity plays a significant role in air conditioning performance, primarily because it affects both human comfort and the efficiency of the cooling system. Increased humidity levels can lead to a higher perceived temperature, which means that occupants may feel uncomfortable even at lower actual temperatures. Consequently, air conditioning systems not only have to cool the air but also remove moisture from it, which can lead to increased energy consumption.

When humidity levels are high, the air conditioning system works harder to dehumidify the air in addition to cooling it. This dual function requires more energy, thereby increasing overall energy consumption. Therefore, the correct answer reflects the substantial impact that humidity has on the performance and efficiency of air conditioning systems, illustrating why managing humidity is crucial for optimal comfort and energy use in HVAC applications.