Why Does It Feel Muggy & Humid Inside When the AC Is Running?

It’s mid-summer in Central Kentucky. You walk into your house expecting cool relief—but instead, the air feels sticky, heavy, and uncomfortable. Even though your AC is working, it’s not removing humidity like it should.

This issue is more common than homeowners realize. At Lexington Electrical & HVAC, we regularly help families in Lexington, Richmond, Nicholasville, Georgetown, and surrounding areas figure out why their homes feel humid despite the AC running.

Below are the top reasons your home still feels muggy—and what you can do to fix it.

1. Your AC Is Short-Cycling

If your system turns on and off quickly without staying on long enough, it’s short-cycling. That means it may cool the air slightly but doesn’t run long enough to remove excess moisture.

🚨 Common Causes:

• Oversized AC unit

• Dirty air filter

• Low refrigerant

• Faulty thermostat

✅ What to Do:
Have our HVAC experts perform a full system diagnosis. Short-cycling can shorten your system’s lifespan and increase energy costs.

2. Your System Is Too Big for Your Home

Many Central Kentucky homes, especially remodeled ones, end up with oversized AC systems. Bigger units cool too quickly and shut off before dehumidifying.

🔎 Signs of Oversizing:

• AC shuts off quickly

• Uneven cooling

• High humidity levels despite low thermostat setting

✅ What to Do:
Schedule a sizing assessment. We’ll help you find the right unit that runs longer, removes more moisture, and improves comfort.

3. Dirty Evaporator Coils Are to Blame

Your evaporator coil is the part of your AC system that absorbs heat and moisture. If it’s coated in dust or grime, it won’t absorb properly—leaving humidity behind.

✅ Solution:
Book a coil cleaning service as part of your annual maintenance or Cozy Club visit.

4. Clogged Condensate Drain Line

When your AC removes moisture from the air, it drips into a condensate pan and exits through a drain line. If that line clogs, moisture builds up—and your home feels damp.

🚱 What to Look For:

• Water near the indoor unit

• Musty smells

• Higher humidity near vents

✅ Fix It:
Flush the line with vinegar or schedule a maintenance visit. Cozy Club members get this done twice a year!

5. You Need a Whole-Home Dehumidifier

If your AC is in good shape but your home still feels damp, you may simply need a dehumidifier. Central Kentucky summers often produce more moisture than a standard AC system can handle.

✅ Our Recommendation:
Install a whole-home dehumidifier that connects to your HVAC system. It keeps moisture between 30%–50%, ideal for comfort and health.

6. Leaky Ductwork Is Letting Moisture In

Your ducts carry cooled air throughout your home. If they’re leaking (especially in crawlspaces or attics), they might be drawing in humid outdoor air.

🛠️ Symptoms:

• Uneven room temperatures

• Dust buildup around vents

• Musty smells in certain rooms

✅ Get It Fixed:
We offer duct inspections and sealing to improve airflow, reduce humidity, and increase energy efficiency.

7. Filters Are Dirty or Blocked

Even something as simple as a clogged air filter can reduce airflow, stress your system, and prevent it from properly controlling humidity.

✅ DIY Tip:
Change filters every 30–60 days during summer. Cozy Club members get filter checks included during seasonal inspections.

🌀 Join the Cozy Club for Year-Round Comfort

Want us to handle this for you? Our Cool & Cozy Club membership includes two professional HVAC inspections per year, where we check:

• Coils and refrigerant

• Condensate lines

• Humidity levels

• Airflow and filters

• Electrical components

✅ Membership Includes:

• 2 HVAC inspections per year

• 1 free electrical inspection

• 10% off repairs and accessories

• 3% off full HVAC system replacements

• $25 gift card for every referral

• Priority service when you need it most

💰 Just $265/year for 1–2 systems
📞 Call (859) 457-0426 to sign up or book service
🌐 lexelectricalandhvac.com

Conclusion: Beat the Humidity Before It Becomes a Bigger Problem

If your AC is running but your home still feels muggy, don’t wait—this is more than just an inconvenience. It’s a warning sign of poor airflow, clogged drainage, or even the wrong equipment size.

Trust Lexington Electrical & HVAC to find the source of the issue and restore your comfort. And for homeowners who want to stay ahead of problems, the Cozy Club makes it easy to stay protected.

❓ FAQs

Q1: Is it normal to still feel humidity when the AC is on?
No. A properly working AC should cool and dehumidify. Excess humidity signals a problem.

Q2: What humidity level should my home be?
Between 30%–50% is ideal. Anything above 55% feels sticky and promotes mold.

Q3: Will a dehumidifier fix the issue?
It can help—but if the AC is undersized, leaking, or dirty, it’s only part of the solution.

Q4: Is this covered in my Cozy Club membership?
Yes! Our inspections check your entire system, including coils, drains, and humidity control.