High humidity makes your home feel clammy, promotes mold growth, and damages furnishings. Understanding humidity helps control it.
Signs of High Humidity
- Condensation on windows
- Musty odors
- Mold or mildew growth
- Peeling paint or wallpaper
- Warped wood
- Allergic reactions worsening indoors
Normal AC Dehumidification
Air conditioning naturally removes humidity. As warm, moist air passes over the cold evaporator coil, moisture condenses and drains away.
However, several factors can reduce this dehumidification: - Oversized AC cools quickly without running long enough to dehumidify - Short cycling limits dehumidification time - Mild weather may not trigger enough AC runtime
Improving AC Dehumidification
Run the fan in AUTO mode. Running the fan continuously re-evaporates moisture from the coil back into the air. AUTO allows humidity to drain between cycles.
Proper sizing matters. Oversized systems are particularly poor at dehumidification. Correct sizing improves both comfort and humidity control.
Variable-speed systems modulate capacity and run longer at lower intensity, removing more moisture than single-speed systems cycling on and off.
Dedicated Dehumidification
When AC is not enough, dedicated dehumidifiers provide targeted moisture control:
Portable dehumidifiers work in specific rooms or areas. They require regular emptying or drain connection.
Whole-house dehumidifiers integrate with your HVAC system, treating air throughout the home. They handle more capacity and require less maintenance.
Reducing Moisture Sources
Address sources of excess moisture: - Use exhaust fans when cooking and bathing - Vent dryers outside - Fix plumbing leaks promptly - Ensure proper drainage around the foundation - Avoid hanging wet laundry inside
Bay Area Humidity Patterns
Coastal areas experience marine layer humidity, especially summer mornings. This can feel clammy even when temperatures are comfortable.
Fog belt homes may need dehumidification even without traditional AC needs.
Rainy season brings elevated humidity throughout the region. Homes without regular cooling may need seasonal dehumidification.
Ventilation Strategies
Strategic ventilation can reduce humidity: - Open windows when outdoor humidity is lower than indoors - Use whole-house fans to exchange air - Run bathroom fans after showers until humidity drops
Monitor outdoor versus indoor humidity to time ventilation effectively.
When to Seek Help
Persistent humidity despite control efforts may indicate: - HVAC problems affecting dehumidification - Water intrusion or leaks - Inadequate ventilation - Need for dedicated dehumidification equipment
Professional assessment identifies the underlying cause and recommends appropriate solutions.