Gravity drainage refers to a condensate removal system that relies solely on the natural pull of gravity to move water from the Condensate Drain Pan to the outside. For this to work correctly, the drain pipe must have a downward slope of at least 1/4 inch per foot of horizontal run. In many Mobile Home Air Handler installations, the unit is elevated specifically to allow for this effortless drainage. If the system is installed below the exit point, a Condensate Pump must be added as a field-installed accessory. Proper gravity drainage prevents water from backing up and causing mold growth or electrical shorts within your ACIq system. It is the simplest and most reliable way to handle the gallons of water your AC removes from the air every day. Ensuring that your Ducted system is level is the first step in guaranteeing successful drainage. This "passive" system is preferred by many installers for its lack of moving parts.