Symptom
House feels humid even with the AC running?
A house can feel damp with the AC running when the system cools the air without running long enough to pull moisture out — most often because it's oversized — or because humid air is getting in through leaky ducts, ventilation or poor exhaust. Indoor humidity above about 60% feels clammy and encourages musty odors. The fix depends on the cause, so it's worth measuring before buying equipment.
Worth booking. Not an emergency, but persistent high humidity can lead to mold and damage over time. Book an assessment.
What usually causes this.
These are the common possibilities, not a diagnosis. A page cannot tell which one it is — that takes a technician testing the system.
- Refrigerant lines
- Ducts & vents
- The house itself
- Indoor coil
- Blower
- Oversized air conditioner
- A system that's too big cools the house quickly and shuts off before it has removed much moisture. The result is a house that's cold and clammy at the same time.
- Fan set to On
- With the fan running constantly, water that collected on the coil can evaporate back into the house between cooling cycles.
- Mild-weather humidity
- In spring and fall the AC barely runs, so it removes little moisture — while outdoor humidity on the coast stays high.
- Leaky return ducts
- Return ducts leaking in a hot, humid attic or crawlspace pull that air straight into the system.
- Low airflow or refrigerant problems
- Both reduce how well the coil removes moisture.
- Exhaust and ventilation
- Bath and kitchen fans that don't vent outside, or ventilation bringing in more outdoor air than the system can dry.
What you can safely check.
- Set the thermostat fan to Auto, not On.
- Use an inexpensive hygrometer to measure indoor humidity for a few days. Somewhere around 45–55% is a common comfort target; above 60% is where problems start.
- Run bathroom exhaust fans during and after showers, and check they vent outside.
- Keep the filter clean and the vents open.
Leave these alone
- Turning the thermostat way down to fight humidity — it usually makes the house colder and still damp.
- Sealing or modifying ductwork in the attic yourself.
Call rather than book online if:
- Water is dripping from the indoor unit or ceiling
- Mold is spreading quickly on walls, vents or ceilings
What we check when we get there.
In order, and every time — the point of a diagnostic is to find out which cause it is before anything is replaced.
Indoor relative humidity
45–55%Clammy and musty
above about 60%
- 01A humidity assessment measures indoor humidity and checks the system's run times, airflow, charge, drain and duct condition.
- 02Only then is equipment discussed — sometimes the answer is a fan setting or a duct repair; sometimes it's a whole-home dehumidifier or, at replacement time, correctly sized variable-speed equipment.
What it is likely to cost.
Fixing a fan setting or drain costs little. A whole-home dehumidifier is a larger investment, which is why the assessment comes first.
Repair or replace?
If the AC is badly oversized and near the end of its life, the lasting fix is replacing it with equipment sized by a load calculation. If it's newer, a dehumidifier or duct repairs usually make more sense.
Compare repair vs replacement- Indoor air quality assessment
- From $149
- Whole-home dehumidifier
- From $1,795
- Condensate drain clearing
- From $149
Prices are starting points for standard work in the Savannah area. Final price depends on the system and site, and is confirmed before work begins. Permits and code-required upgrades may be additional.
Questions people ask about this.
- What humidity should my house be?
- A common comfort target is around 45–55% relative humidity. Above about 60%, homes tend to feel clammy and musty.
- Will a bigger air conditioner fix humidity?
- Usually the opposite. A bigger system runs in shorter bursts and removes less moisture.
- Do I need a dehumidifier if I already have AC?
- Sometimes — especially for spring and fall, when the AC barely runs. A whole-home dehumidifier controls humidity independently of cooling.
Work out the decision:Humidity & ComfortSystem Sizing Guide
Further reading:Getting HVAC right in a new buildSingle-stage, two-stage or variable-speed: which is worth it here?Do you need a whole-home dehumidifier on the coast?
The service that fixes it.
Indoor Air Quality is the work behind this symptom. Its page covers what is involved, how it is quoted and what we stand behind.
- 01Indoor Air QualityHumidity control, filtration, purification and ventilation — the half of comfort a thermostat does not measure.
- 02AC Installation & ReplacementNew and replacement cooling systems, sized to the house rather than to whatever was there before.
- 03Maintenance PlansTwice-yearly service that catches small faults before they become July breakdowns.
Symptoms that sit next to it.
Systems rarely fail in one way only. If one of these is also true, say so when you book — it narrows the diagnosis before anyone arrives.
The system runs, but the house feels damp, some rooms never keep up, or the bill jumped.
- Some rooms too hot or coldWhen one room or a whole floor stays hotter or colder than the rest, the equipment is often fine — the problem is getting air to that space.
- Power bill suddenly higherHeating and cooling are usually the largest share of a home's electricity use, so a sudden jump in the bill often points to the HVAC system running longer or harder than it should.
Not sure which it is?Describe it to the assistant
Everything else we are called about.
The whole index, in three groups.
HUMIDITY, AIRFLOW & ENERGY BILLS
Get it looked at.
We cover Savannah, the Coastal Empire and the South Carolina Lowcountry. Tell us what the system is doing — you do not need to know the cause. The diagnostic price is given to you before the visit, and the repair price before any work starts.
No heat, or no cooling at all?Call rather than send a request — (912) 858-3737 is answered around the clock.