This is the time of year when our office gets several calls a week from homeowners who have discovered mold growing on their furniture, shoes, and walls. Often saying, “the mold seemed to appear overnight”, they have trouble dealing with the sudden impact of mold appearing all over their house.
Here in North Carolina, we often enjoy extended late summer weather for several weeks in a row. Temperatures in the 70s during the day and 50s at night, humidity below 80 percent, and a chance to turn off the HVAC that seemed to never stop running from Memorial Day to Labor Day combine to form a perfect storm: little or no air movement and filtration, and humidity just high enough to dampen the dust on your stuff. The result is mold and bacteria using the dampened dust in your house as a food source. It only takes a few days to establish visible fuzzy colonies that will get your attention.
To help prevent mold growth, we suggest running the A/C or heat (or HVAC in ‘fan’ mode) for at least an hour each day. The fan on the air handler pushing air around the house helps remove moisture and dust particles as the air moves through the ducts and passes through the return filter. Add a ceiling fan or two and the house should stay dry enough to keep mold at bay. Although running fans and occasionally cutting on the heat or A/C will usually be enough to keep the house dry, it may be necessary to run a dehumidifier, especially when a few rainy days push the humidity upwards.