AC running but the house feels sticky

Why Greenville houses feel it

The Greenville NOAA station doesn't measure humidity, but it does record the overnight low, and on a summer night the low sits close to the dew point. Over 2016-2025 the station averaged 53.2 nights a year when the low stayed at 72°F or above, up from 42.1 over 1991-2020. In 2026 there were 71 by late October. Those are the nights a system has to keep running just to keep the house dry. The full data.

Nights per year when the low stayed at 72°F or above

The common causes

• An oversized system. It cools the house fast and shuts off before the indoor coil has been cold long enough to wring much water out. The Department of Energy warns that oversized systems cycle on and off too often. It often shows up in a house where a bigger unit replaced a smaller one.
• The fan set to on. With the thermostat fan on continuously, water that collected on the coil can blow back into the house between cooling cycles. Greenville Utilities Commission's warm-weather advice is to leave the fan on auto.
• Leaky ducts in a crawlspace or attic. A return duct with a gap pulls warm, damp air from under the house straight into the system. Crawlspace ducts.
• Low refrigerant or a dirty coil. Both cut the system's ability to cool the coil enough to remove moisture.
• Air leaks in the house itself. Older houses let in a lot of outside air. About 30% of homes in the Pitt County ZIP codes we cover were built before 1980 (Census ACS 2020-2024).

What to check yourself

1. Set the thermostat fan to auto.
2. Change the filter.
3. Watch the run time on a hot afternoon. Short cycles of a few minutes, over and over, point at sizing. A system that runs nonstop and still can't get the house below 78 points somewhere else.
4. Look at the condensate line outside or at the air handler while it runs. On a muggy day it should be dripping steadily.
5. A cheap hygrometer from a hardware store tells you the indoor humidity. Write the readings down for the technician.

What a technician can do

Check the refrigerant charge and airflow, clean the coil, and measure the temperature drop across it. On many systems the blower speed can be adjusted so air moves across the coil more slowly, which removes more water. If the system is badly oversized, the real fix comes at replacement: a size based on a Manual J load calculation, not the old unit's tonnage. Some houses also get a dedicated whole-house dehumidifier. How sizing works.