We live in Hawaii and mold is a huge problem here. There are times during the day when the dewpoint spread is only a few degrees. This means that any object that is cooler than the air temperature will condensate. If you can't control the moisture you can't control the mold. Another major factor is the materials in your house. Things like unfinished birch plywood will absolutely mold if left in open air, where other woods like hardwoods don't have as many problems.