How Does an Air Conditioner Work? There are two laws of physics that we should review before explaining the inner workings of your air conditioning system. Combined Gas Law The first is the relationship between pressure and temperature, known as the combined gas law since it combines Boyle’s Law , Charles’s Law , and Gay-Lussac’s Law : Boyle’s Law states that the pressure-volume product is constant. Charles’s Law shows that the volume is proportional to the absolute temperature. Gay-Lussac’s Law says that the pressure is proportional to the absolute temperature. In simple English, the combined gas law says that whenever you heat up a gas, pressure also increases. And vice versa, whenever you pressurize a gas, heat also increases. If pressure increases, so does its temperature. This is why a tire heats up as you pump it with air. If pressure decreases, so does its temperature. This is why an aerosol can gets colder as you depress the nozzle and relea