.Cssg-vzo.jpg)
High humidity in the Southeast can make your building feel sticky, damage materials, and encourage mold. Here is how to keep moisture under control so your space stays comfortable and your building stays healthy.
From Florida to the Carolinas and across the Gulf states, summer brings heat and heavy moisture in the air. Your cooling system does more than lower the temperature; it also pulls moisture out of the air. When that part of the system is undersized, neglected, or not running long enough, humidity inside the building climbs. The result: discomfort, complaints, and sometimes real damage to the structure and contents. This guide explains why humidity control matters and what you can do about it.
Why Humidity Matters in Your Building
Too much moisture in the air causes several problems that go beyond feeling sticky.
- Comfort: People feel hotter when the air is humid. A space that is 75 degrees with high humidity can feel worse than 78 degrees with drier air.
- Mold and mildew: Damp conditions support mold growth on walls, ceilings, and in ductwork. That can affect air quality and trigger health concerns.
- Damage to materials: Wood, paper, and some electronics can warp, swell, or corrode when humidity stays high for long periods.
- Odors: Musty smells often come from excess moisture and the growth it encourages.
Keeping relative humidity in a reasonable range (often between 40 and 60 percent, depending on use) improves comfort, protects the building, and supports better indoor air quality.
Why Southern Buildings Struggle With Humidity
Outdoor air in the Southeast often carries a lot of moisture. When that air gets inside through doors, windows, or leaks, your cooling system has to remove both heat and moisture. A few common issues make that job harder.
Oversized or Short Cycling Equipment
If the cooling system is too big for the space, it cools the air quickly and then shuts off. It never runs long enough to pull much moisture out. The result: the room is cool but still damp. Right sized equipment runs longer cycles and does a better job dehumidifying.
Poor Maintenance
Dirty coils, clogged drains, and low refrigerant all reduce how well the system removes moisture. Regular HVAC maintenance keeps the equipment doing its full job, including dehumidification.
Leaky Buildings
Gaps around doors, windows, and roof penetrations let warm, humid outside air in. The system then has to work harder to condition that air. Sealing obvious leaks and ensuring doors close properly helps.
No Dedicated Dehumidification
In some buildings, especially those with variable occupancy or in very humid areas, cooling alone is not enough. Dedicated dehumidification equipment or enhanced ventilation strategies may be needed to keep humidity in check.
Practical Steps to Improve Humidity Control
You do not need to be an expert to make progress. Start with these steps.
- Check thermostat settings: Avoid setting the cooling so high that the system barely runs. Moderate settings allow longer run times and better moisture removal.
- Change filters on schedule: Dirty filters restrict airflow and can reduce both cooling and dehumidification. Follow the filter schedule that fits your building.
- Have coils and drains inspected: As part of routine service, have your technician check evaporator coils and condensate drains. Clean coils and clear drains help the system remove moisture properly.
- Fix obvious air leaks: Weather stripping, door sweeps, and sealing around penetrations reduce the amount of humid outdoor air entering the space.
- Consider a humidity assessment: If you have ongoing comfort or mold concerns, a professional can measure humidity levels in different zones and recommend equipment or control changes.
When to Bring in a Professional
If you have already addressed filters, thermostat, and obvious leaks and humidity is still a problem, it is time for a deeper look. A qualified technician can:
- Verify that the cooling equipment is the right size and operating correctly.
- Check refrigerant charge and airflow; both affect how much moisture the system can remove.
- Recommend upgrades such as variable speed equipment or dedicated dehumidification if needed.
Garrett Mechanical works with commercial buildings across the Southeast, including Florida, Georgia, North Carolina, and South Carolina. We see humidity issues every season and can help you track down the cause and improve comfort. If your building feels damp, smells musty, or you have had mold concerns, contact us to schedule an assessment. Getting humidity under control now can prevent bigger problems and keep your space comfortable year round.