How important is evacuation in the refrigeration or air conditioning system.

The evacuation of the system is one of the most important processes in refrigeration and air conditioning. In refrigeration and air conditioning systems the vacuum function is to remove air and moisture before the refrigerant is charged. The air consists basically of 79% of nitrogen, 20% of oxygen and 1% of other gases including water vapor. A system that has not been properly evacuated will present problems of high pressures, due to the non-condensable gases, problems of chemical attacks to metallic parts of the system to the varnish of the motors and the oil, causing their decomposition.