Yes, air conditioners do work harder in high humidity conditions. This is because air conditioners not only cool the air but also remove moisture from it, reducing the relative humidity indoors. When the humidity is high, the air conditioner has to work extra hard to dehumidify the air before cooling it.
The cooling process of an air conditioner involves two main stages:
Sensible cooling: This is the process of reducing the temperature of the air without changing its moisture content. During this stage, the air conditioner cools the air by passing it over the evaporator coil, where the refrigerant absorbs heat from the indoor air.
Latent cooling: This is the process of removing moisture (humidity) from the air. When warm, humid air comes into contact with the cold evaporator coil, the moisture in the air condenses into water droplets, which then drip off the coil and are drained away.
In high humidity conditions, the air already contains a significant amount of moisture. As a result, the air conditioner needs to spend more time and energy on the latent cooling process to remove excess moisture from the air before it can effectively cool it. This means the compressor and other components of the air conditioner have to work harder and run for longer periods to achieve the desired indoor temperature and humidity level.
Higher humidity levels can also reduce the overall comfort level indoors, as it may feel warmer due to the decreased evaporative cooling effect on the skin. Additionally, the higher workload on the air conditioner can lead to increased energy consumption and potentially higher utility bills. To improve indoor comfort and energy efficiency in high humidity conditions, some air conditioners are equipped with features like variable-speed compressors and humidity control settings.