Condensate Drain Line
Your air conditioner does more than just cool your home. It also helps dehumidify your home, by drawing heat and moisture from the air as it passes over the evaporator coil. This humidity turns into condensation, which needs to be expelled to the exterior of the home. This is where the job of the condensate line comes in. This drain connects directly from your air conditioner to the outdoors, giving condensation a way out of your home.
In a dry climate where relative humidity remains below 50 percent most of the time, the evaporator coil in a central air conditioner will send about about 5 gallons of water down the drain per day. In humid climates, however, the drain pipe may move as much as 20 gallons per day. The condensate drain line needs to expel away from the foundation of your home.
In this video the condensate drain line is expelling next to the foundation. You do not want up to 20 gallons of water running near your foundation everyday.