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High Humidity Inside the Home
in Garland, TX
Garland gets significant humidity especially from April through October, and your AC is supposed to pull that moisture out of the air while it cools. When humidity stays high inside, the AC is failing at that job. A sticky, clammy feeling indoors even at 75°F means moisture levels are too high, and at above 60 percent humidity, mold starts growing in walls and ductwork.
Quick Answer
High indoor humidity in Garland is often a sign that the AC is not running long enough, is oversized, or is low on refrigerant. The AC removes moisture from the air during each cooling cycle, and if cycles are too short, the humidity never drops. Call (361) 338-5229 if indoor humidity stays above 60 percent, because that level encourages mold growth.
Telltale Signs
Warning Signs to Watch For
- Air inside feels damp or sticky even when the temperature is comfortable
- Condensation on windows or window sills
- Musty smell in certain rooms or near vents
- Visible mold spots on walls near exterior corners
- Wallpaper peeling or wood trim starting to warp
- Hygrometer or smart thermostat reads above 60 percent relative humidity
Root Causes
What Causes High Humidity Inside the Home?
Oversized System Short Cycling
An oversized AC unit cools the air temperature quickly but does not run long enough to pull significant moisture out of the air. Moisture removal happens over the full length of a cooling cycle. Many Garland homes in the South Garland area received replacement systems in the 2000s that were bumped up a size unnecessarily, and the humidity problem started right after.
The Fix
System Sizing Review and Replacement
Correcting the unit size to match the actual load allows the system to run full cycles. Longer run times mean the coil has time to wring moisture out of the air properly.
Low Refrigerant Reducing Dehumidification
A properly charged evaporator coil runs at a temperature cold enough to cause moisture to condense out of the air onto the coil, draining away. When refrigerant is low, coil temperature rises and the coil loses its ability to pull moisture. This is a slow change that sneaks up on homeowners over several seasons.
The Fix
Leak Repair and Refrigerant Recharge
After the leak is sealed and the system is recharged to spec, coil temperature drops back to where it should be. Dehumidification performance returns within one full cooling cycle.
Leaking Ductwork Pulling In Attic Air
Attic air in Garland in the summer is both hot and extremely humid. If supply ducts have gaps or loose joints, they pull attic air into the airstream delivered to the house. This adds humidity to the air instead of removing it. A 10 percent duct leak in a Garland attic during July can push indoor humidity up significantly.
The Fix
Duct Sealing
Leaks in the ductwork get sealed with mastic sealant from inside the attic. Once attic air is no longer mixing into the conditioned air, humidity inside the house drops to a normal range.
Self-Diagnosis
Which Cause Applies to You?
Check the signs you're observing to narrow down the likely root cause before your inspection.
| What You're Seeing | Oversized System Short Cycling | Low Refrigerant Reducing Dehumidification | Leaking Ductwork Pulling In Attic Air |
|---|---|---|---|
| AC replaced recently but humidity problem started after | |||
| Humidity problem developed gradually over 2 or 3 seasons | |||
| Humidity worse when system runs than when it is off | |||
| Ice on refrigerant lines paired with high indoor humidity | |||
| Short on-off cycles with no real cool-down period | |||
| Musty smell from vents stronger in summer |
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