Why is my house still humid even though the AC is running?
If your AC is running but your home is still humid, the problem could be an undersized system, poor airflow, low refrigerant, or high outdoor humidity. In North Alabama’s climate, humidity control is critical for comfort and health. At Vandys LLC, we diagnose humidity problems and recommend solutions
call (256) 225-7311 for a $110 diagnostic.
Quick Answer
Common causes: undersized system, poor airflow, low refrigerant, or thermostat set too high. Call Vandys LLC for a $110 diagnostic. Indoor air quality solutions range from $650-$2,250.
Understanding Humidity in Alabama
North Alabama’s climate is naturally humid. Our proximity to water sources and high summer temperatures create ideal conditions for moisture. Typical humidity levels:
- Comfortable: 30-50% relative humidity
- Humid: 50-60% relative humidity
- Very humid: 60%+ relative humidity
In summer, outdoor humidity often exceeds 70%. Your AC must work hard to dehumidify while cooling.
Undersized HVAC System
The most common cause of humidity problems is an undersized system. If your AC is too small for your home, it can’t remove enough moisture while cooling. Why this happens:
- System was sized incorrectly during installation
- Home has been expanded (added rooms, finished basement)
- System is old and has lost capacity
The fix: Call Vandys LLC for a professional load calculation. We’ll determine if your system is undersized and recommend replacement if needed. Average installation: $10,400-$19,800.
Poor Airflow
If your AC isn’t circulating air properly, humidity builds up in certain areas. Common causes:
- Dirty air filter (restricts airflow)
- Blocked vents or returns
- Ductwork leaks or disconnections
- Blower fan not working properly
The fix: Check your air filter and replace if dirty. Ensure all vents and returns are open and unblocked. Call Vandys LLC for a $110 diagnostic if problems persist.
Low Refrigerant
Refrigerant is essential for both cooling and dehumidifying. If your system is low on refrigerant, it can’t remove moisture effectively. Warning signs:
- AC runs constantly but doesn’t cool
- Hissing sounds near outdoor unit
- Ice buildup on indoor unit
- Humidity remains high despite AC running
The fix: Call Vandys LLC for a diagnostic. We’ll locate the leak, repair it, and recharge your system. Motor repairs average $700-$900.
Thermostat Set Too High
If your thermostat is set to 78°F or higher, your AC may not run long enough to dehumidify effectively. AC removes humidity while cooling. If it reaches the set temperature quickly, it shuts off before removing enough moisture. The fix: Lower your thermostat to 76-77°F. This allows the AC to run longer and remove more humidity.
Frozen Evaporator Coils
This is a major problem in Alabama’s humid climate. When the evaporator coil freezes, it can’t dehumidify. Why it happens:
- Low refrigerant
- Dirty air filter
- Restricted airflow
- System running in cold weather
The fix: Turn off your AC immediately to prevent compressor damage. Call Vandys LLC for emergency service. We’ll thaw the coil and identify the root cause. Emergency weekend service is $175 additional.
Outdoor Humidity Too High
Sometimes the problem isn’t your AC—it’s the outdoor humidity. On extremely humid days (70%+ humidity), even a properly functioning AC struggles to dehumidify. What to do:
- Close windows and doors
- Use exhaust fans in bathrooms and kitchen
- Run your AC continuously (don’t use thermostat)
- Consider a whole-home dehumidifier
Whole-Home Dehumidifier Solution
If humidity remains high despite a properly functioning AC, consider a whole-home dehumidifier. This removes excess moisture from your entire home. Benefits:
- Improves comfort
- Prevents mold and mildew
- Protects furniture and electronics
- Reduces allergens
Cost: $650-$2,250 at Vandys LLC (depending on capacity and features)
Indoor Air Quality Solutions
At Vandys LLC, we offer comprehensive indoor air quality solutions:
- Whole-home dehumidifiers: $650-$2,250
- Air purifiers: Included in some systems
- UV lights: Kill mold and bacteria
- Ductwork sealing: Improves efficiency
Local Pricing for Athens & Huntsville
At Vandys LLC, we solve humidity problems:
- Service call (diagnostic): $110
- Whole-home dehumidifier: $650-$2,250
- Motor repair: $700-$900
- New system installation: $10,400-$19,800
- Financing: 0% APR for 12 months on systems over $2,000
When to Call Vandys LLC
If your home is humid despite AC running, call us for a diagnostic. We’ll identify the problem and recommend solutions. Don’t ignore humidity—it promotes mold growth and reduces comfort.
Contact Vandys LLC
Phone: (256) 225-7311
Service Areas: Athens, Huntsville, Harvest, Madison, Decatur, New Market, Owens Crossings
Hours: 7am-6pm Monday-Sunday
Emergency Service: Available 24/7
Financing: 0% APR for 12 months on systems over $2,000