Any Los Angeles air conditioning contractor will tell you that our air is brimming with water; 65% average humidity. All that water is processed by your air conditioner and becomes condensation.
You know how a cold drink on a hot day creates condensation on the outside of the glass? The same thing happens when warm air from your home comes in contact with your evaporator coil. Condensation is created. A properly installed heating and cooling system is designed to deal with all the excess water produced, and there is a LOT of water at times! Proper systems are equipped with a drain pan and pipe running either to the ground outside your house or maybe into a rain gutter on the roof. If this drain line is clogged, you can be facing some potentially serious issues.
When my company installs an AC system we take an extra step to give my customers a warning if their condensate drain is clogged. We place the secondary drain outlet over a window or in a similarly noticeable place. When the homeowner sees water dripping they call for service. This way the problem can be remedied BEFORE it causes damage to your home.