How to Control Humidity and Reduce Excess Moisture This Summer

With summer weather here, it’s time to think about controlling the humidity and moisture levels in your home or building. High indoor humidity levels not only make the heat feel sticky and unbearable, but lingering moisture from summer thunderstorms can also cause serious property damage.

Fortunately, you can take steps to prevent damage from excess moisture and to lower the relative humidity to more comfortable levels between 30% and 50%.

Signs of High Humidity and Excess Moisture Levels

Besides the comfort factor, indoor humidity levels above 60% encourage mold growth. Look for these signs that your home or building might have a moisture or humidity problem:

• Wall or ceiling discoloration that’s consistent in multiple lighting conditions
• Peeling paint
• The scent of mold and mildew
• Floorboards that creak more than usual
• Visible condensation on windows, pipes and mirrors
• Condensation on walls and shelves (they may also feel soft)
• Exterior siding that’s softening or crumbling
• Rainwater pools in a flowerbed or underneath a hose bibb
• Moist attic or crawlspace

Also, if family members or employees experience moderate to severe allergy symptoms, that could also point to a possible issue.

How to Control Humidity Levels Indoors

To control summertime humidity on your property, start with the equipment that you likely already have.

• Ensure efficient operation of your air conditioning system. Air conditioners have components that remove moisture from the air like a standard dehumidifier. To keep your AC running efficiently, change the air filter every 3-6 months, ensure the evaporator coils are clean, and check the drain pan and drain line pipe for clogs. An AC technician can perform these tasks during a routine maintenance appointment.
• Keep ventilation fans running and in good condition. Humidity levels can soar without proper ventilation. Kitchen and bathroom ventilation fans or exhaust systems should be repaired quickly if you or a tenant notices a mildew smell. For less-used spaces, attic fans can help prevent mold growth and structural deterioration, and plastic barriers can insulate crawlspaces.

The following property maintenance tips can also control indoor humidity levels:

• Re-caulk windows and plumbing fixtures
• Cover cold water pipes with insulation
• Replace wallpaper or vinyl with paint
• Install storm windows

If humidity levels remain high, consider purchasing a dehumidifier, which removes excess moisture from the air. Some dehumidifiers have pumps or drain hoses that direct the collected water elsewhere, but many units require manually draining the collection tank. If you buy a dehumidifier in the latter category, be sure to empty the accumulated water regularly, or it could become a source of biological pollutants.)

How to Control Excess Moisture and Humidity from Outside

One way to decrease indoor humidity levels is to make sure that the exterior of your home or building repels rainwater effectively, especially the attic and basement. The following steps can help keep moisture outside your home:

• Get your roof inspected at least once per year (or after a severe weather event)
• Inspect the perimeter after storms for standing water pools near the foundation
• Keep gutters clean so that rainwater can drain properly, or install gutter guards to reduce gutter maintenance needs
• Hire a professional to treat your home’s foundation with materials that absorb water