Humidity and Mold Growth
What are the conditions for mold growth? Extended periods of time where a home is 70% relative humidity is just right for mold. It is ideal to keep your home under 55% RH day and night. Humidity creeps into every porous object (furniture, drapes) in your home while humidity is high. As your AC removes humidity from the air, your furniture then adds it right back. You have to get ahead of this cycle. Check out the detailed information from FSEC at the University of Central Florida in the link below.
Vacant Home Mold Prevention
Florida vacant home situations are considered the following: Away for a vacation for a week or two. Snowbird type situation where you are out of your home for the summer. Several cooling strategys were tried by UCF (link below), and the most effective was:
Using a programmable thermostat and setting the cooling to 74 degrees between 3AM and 5AM. In older homes it may be needed to add cooling to 74 degrees between 10AM and noon for a total of 4 hours per day.
Why do I have high humidity?
If you have humidity that pushes over the 65% mark what could be the cause? On cooler days and nights with high humidity your system cool to set temp too quickly. (short cycling) In this case you may have to lower your thermostat set temperature to insure the system runs long enough to remove the humidity. Also cooling equipment that is over-sized for the space (without two stage or variable output) can cool so quick it will remove the sensable heat (the heat you feel) without removing the latent heat (the heat contained in the moisture in the air)