AC Condensate & HVAC Leak Damage in Tuscaloosa County

Tuscaloosa County spends four months a year at a dew point that keeps every cool surface in a building on the edge of sweating. The post-2011 rebuild streets through Alberta and Forest Lake put air handlers in attics above finished ceilings. The older houses off University Circle run ductwork through open crawl spaces instead. Both arrangements put cold metal in hot, wet air.

A system that cools faster than it dries

An air conditioner only removes humidity while the coil is cold and air is moving across it. A unit sized larger than the house needs satisfies the thermostat in a few minutes, shuts off, and starts again a few minutes later. The room temperature is fine. The moisture never gets pulled out, because the coil never runs long enough at a time to condense much of anything.

What that leaves is a house at a comfortable temperature carrying far more moisture than it should. The excess finds the coldest surfaces available and condenses there instead: supply registers, the metal boot behind a ceiling grille, the first foot of duct off the plenum, the inside face of a closet wall against an exterior corner. None of that looks like a plumbing failure, and it is treated as one anyway when the drywall stains.

Ductwork sweating where nobody looks

Duct running through an unconditioned attic or an open crawl space carries air well below the dew point of the air around it. The insulation wrap and its vapor barrier are the only things keeping the two apart. Where that wrap has been compressed by somebody kneeling on it, torn during another trade's work, or simply come unsealed at a joint, the metal underneath sweats every time the system runs.

In a crawl space that water drips onto the ground or onto the vapor barrier and is invisible from inside the house; the first sign is a musty hall closet or a subfloor reading wet from below. In an attic it runs down the duct to the low point, collects at a boot or a strap, and comes through the ceiling in a spot that has no relationship to where the sweating started.

The float switch and the choice it forces

A float switch sits in the drain pan or the drain line and shuts the system down when water rises where it should not be. It is the only part of the arrangement that will stop a blocked drain from reaching a ceiling. On an attic air handler above finished space it is not optional equipment in any practical sense, and a good number of the ceilings we open did not have one.

The reason people disable them is understandable. A float switch does its work by turning the air conditioning off in August, usually on the hottest afternoon of the week, with no explanation offered. The switch gets jumped out so the house cools, the drain stays blocked, and the water goes into the building instead. If your system shut itself off and somebody made it run again without clearing anything, that is worth knowing now.