Air Conditioning And Comfort

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The purpose of an A/C system is to make the driver and passengers comfortable. An A/C system achieves this by cooling the air temperature inside the passenger compartment and removing moisture (humidity), dust, and pollen particles.

Fig 1: Identifying Moisture And Lowering Humidity, An A/C System Achieve Passenger Comfort At Higher Temperatures

Courtesy of BMW OF NORTH AMERICA, INC.

By removing moisture and lowering the humidity, an A/C system can achieve passenger comfort at higher temperatures. The reason for this is that the human body cools itself by allowing moisture on the skin to evaporate.

The relative humidity governs how quickly evaporation occurs:

High relative humidity = low evaporation rate.
Low relative humidity = high evaporation rate.
When the A/C system removes moisture from the air, the relative humidity in the passenger compartment decreases. By reducing the relative humidity, the A/C system increases the rate at which the moisture on passengers' skin will evaporate.