Inspect your attic AC evaporator monthly for signs of water leakage.
In newer homes, the air conditioner evaporator, located within the air handler or the furnace, is often located in an attic. Normal operation of the system produces condensation that drains to the outside of the home. However, when something goes wrong, that condensation can spill into the attic and cause ceiling damage to the top floor of your home.
How HVAC Systems Work
Central air-conditioning, otherwise known as HVAC, is a two-part system that features a compressor located outside a home connected via copper tubing to an evaporator located inside the home. Gaseous refrigerant is pressurized in the compressor, turned to liquid and sent to the evaporator. The evaporator houses a series of copper tubes (known as the coil), which get cold from the pressurized refrigerant. The blower (sometimes part of the furnace) pushes warm air across the coils, which is chilled, then sent around the home via the air ducts. The liquid in the coils turns back to gas as it absorbs the warm air and returns to the compressor to start the cycle again.
Condensation
While an HVAC system is closed and does not leak, it does produce large amounts of condensation. The condensation is created when the warm air meets the chill copper pipes containing liquid refrigerant. The warm/cold combination creates condensation, which drips into a pan and, in most cases, is drained away via a PVC drainage pipe. Condensation can be found in two locations, outside along the supply line that is sending chilled refrigerant to the evaporator and within the evaporator itself along the copper pipes of the coil. Normal operations will make these pipes moderately to very "sweaty."
Leaking Condensation
Condensation will drain normally via a PVC outlet pipe that usually drains out near the compressor unit. A steady stream of water in this location is normal. If water starts to drain from the secondary drain, usually located over a window or doorway, you may have a potential problem. Unfortunately, not all homes have a secondary drain and rely on a drain pan in the attic. Water entering that drain pan instead of the outdoor drain may overflow and cause ceiling damage. Worse yet, shoddy building practices sometimes have the secondary drain emptying directly to the attic floor. Any slight flow from this sort of drain will create ceiling damage to the floor below.
Causes of Leaks
The primary drain system can get clogged with mold and fungus, especially in humid locations. A drain pipe clogged with fungus or mold will cause the condensation to back up, and if secondary drainage is not installed, the moisture will spill out of the evaporator. Fortunately, a clogged drain is preventable by pouring a cup of bleach down the drainage vent pipe every month. The vent pipe is an upright open or lightly capped pipe emanating off the primary . If the drain is already clogged, try using a shop vac on the outside end of the drain pipe and adding one part water and one part bleach in the drain pipe vent. If a clog persists, you will need to contact an HVAC professional to remove the clog. Other leaks can be caused by the coils icing up due to low refrigerant levels. The ice can block the drainage, causing the water to spill onto the floor.
Ceiling Damage
Damage from a leaking HVAC unit will show up as a discolored stain on your ceiling directly below your ceiling evaporator. If the spillage is large enough, the Sheetrock or plaster may start to peel away and fall. Shut down your system at the first sign of leakage.
Tags: drain pipe, secondary drain, cause ceiling, cause ceiling damage, ceiling damage