What causes the condensed water to drain from the AC system?

The condensed water drains from the AC system due to the cooling process that occurs when warm air passes over the evaporator coils. As the refrigerant inside the coils absorbs heat, it cools the air, causing moisture in the air to condense into water droplets. These droplets collect and are directed to a drain pan, where gravity causes them to flow out through a drain line, preventing overflow and maintaining efficiency.