[billybek]

You are on the right track just to turn up the temperature when you are not there and let the AC look after the humidity. As mentioned before, using a programmable t stat to get some run time once or twice a day wouldn't be a bad thing either.

I am not familiar with a whole home humidifier but it seems that they are basically an AC system with a thick coil to dry out the air. The condenser looks to reject its heat outside.

Self contained dehumidifiers cool down the air by using a self contained condensing unit and evaporator coil. Leaving one of these operate in a closed home in a hot climate will actually raise the temperature of the house. The energy required to cool the evaporator coil is just discharged in the house. Because of the heat of compression and the inefficiencies of the machine, that means more heat is rejected than is taken in when cooling the air past dew point to dehumidify it. Quite often you will see these located in a cool basement to keep the musty smells away. Some of these will drain by themselves, others you have to dump the water from them.

Service valves positions are for access port closed "on the back seat". (all the way counter clockwise). All the way in clockwise is "on the front seat". This will isolate a compressor on its service valves or isolate the condenser from the liquid line allowing the system to pump down, keeping most of the refrigerant in the condenser. Opening the service valve access to allow placing gauges on the system is just a matter of cranking them in a 1/2 or 1 turn.