Why Does Water Sometimes Soak the Carpet Beneath an Air Conditioning Unit?
During the cooling cycle, an air conditioner pulls a significant amount of moisture out of the indoor air. That moisture turns into liquid inside the unit and is meant to be captured in a drain pan and carried away. If the collection or drainage system fails at any point, water can escape from the front of the unit and soak the carpet.
By Kai Gray
Window air conditioners that don't drain correctly may leak water into the room.
As part of the cooling process, an air conditioner draws considerable humidity out of the air inside a home. The resulting water condenses within the unit and is intended to be captured in a drain pan so it can be disposed of. If that collection and drainage process goes wrong, liquid may spill out of the front of the appliance and onto the carpet.
A Blocked Drain Line
In older units, moisture that gathers inside the air conditioner is normally carried away through a narrow PVC tube that exits at the rear of the machine. Dirt and dust gradually build up inside this tube over time, and it can eventually become entirely clogged. Once that happens, the drain pan keeps filling, and with no other outlet, the water overflows past the pan's edge and drips onto the carpet underneath. Clearing the line by blowing it out typically resolves the issue.
Coil Freeze-Up
When outdoor temperatures drop too far (under 60 degrees Fahrenheit for most models), frost or ice can develop inside the air conditioner. Unlike water, ice cannot drain into the pan and out through the tube, so the system becomes blocked. As temperatures climb and the ice begins to thaw, water may trickle out from the front of the window unit. A carpet that is dry in the evening but wet by morning points to ice as the probable cause.
Moisture From Condensation
Outside air that is warm and humid can slip around the edges of a window air conditioner, where it comes into contact with the cold metal face of the machine and turns into water droplets. If the gap between indoor and outdoor temperature and humidity is wide enough, those droplets will eventually drip onto the floor near the front of the unit. Shining a flashlight just beneath the lower edge of the air conditioner will reveal these droplets.
Faulty Installation of a Window Unit
For a window air conditioner to drain as it should, water has to move from the front of the machine to the back, which means the unit ought to be mounted with its rear about one inch lower than its front. If it was installed perfectly level or tilted down toward the front, water will spill over the front lip of the shallow drain pan and onto the carpet rather than flowing into the drain tube at the rear.
