Running a central air conditioning unit to maintain a comfortable temperature level inside your home when you won’t be there is costly, yet turning the air conditioning off completely in humid areas creates mold and mildew problems inside the home. The solution is a humidistat, which runs the air conditioner to control the humidity level inside the house independently of temperature.
While the thermostat on your air conditioner measures the temperature inside the home, a humidistat measures the humidity. If the temperature is high but the humidity level is low, the humidistat does not allow the air conditioner to run. This prevents the air conditioner from using electricity to cool your home when you aren’t there. If, however, the humidity level inside the home creeps into the range where mold and mildew could become a problem, the humidistat runs the air conditioner until the humidity level is reduced. In this way, you protect your home from mold problems while you are away without having to maintain a specific temperature in the home.
When you will be away for an extended period of time, set things as follows:
Make sure the air conditioner is set to the “cool” and “auto fan” settings.
Set the air conditioner temperature on the thermostat to between 80-85 degrees Fahrenheit.
On the humidistat, set the humidity level to 65 percent. Although mold and mildew do not form at humidity levels below about 68 percent, it is recommended to go with a setting of 65 as humidistat gauges can be off by as much as 10 percent.
Now, if you are going to be living in the home, then set your air conditioner to the temperature that you want, but be sure to turn your humidistat to the “On” position. When it is set to “On”, the humidistat will not control the air conditioner unit. Remember, if you turn the humidistat to the “Off” position, your air conditioner and the humidistat will be turned off and the air conditioner will not cool.