Secondary Condensation Line
Your air conditioner or heat pump in your home produces quite a bit of condensation on the evaporator coils when it is running. This condensation is normal and has to be removed by ways of an appropriate drain system to prevent moisture damage caused by a continuing drip. In most cases a large amount of liquid needs to be drained.
The typical method to drain this condensation is the primary drain pan which is typically an integral part of the air conditioner unit. This pan sits under the coil, collects the condensation and directs it to a drain line so it can be safely drained.
On split air conditioner or heat pump systems with the compressor unit outside and the air handler inside a secondary method of drainage is required to prevent water damage should the primary drain clog, fail or be inadequate to drain away the water. The typical method of doing this is to install a secondary condensation drain pan with a separate drain line under the air handler unit.
If the primary drain should have a problem and fail then the integral pan overflows and leaks out of the unit and into the secondary drain pan where it can be safely drained away. The location of the secondary condensation drain line outlet should be located in a conspicuous location so you will know if it is draining. Anytime you see water leaking out of the secondary condensation drain you know you have a problem with the primary drain.
The constant moisture can corrode the air handler metal case and secondary drain pan causing water leakage into the attic. This moisture can get on the drywall causing water damage to your ceiling. What we see most of the time when a problem occurs with the primary drain system is when water drains into the secondary condensation drain pan we see a rust streak on the exterior of the home or even on the ground in the area of the secondary condensate drain line outlet.
If you ever see this type of problem be sure to call a qualified HVAC contractor and get it fixed right away.