The fan runs at low speed and compressor is on for short duration in large cycles just to remove extra humidity.
Air conditioner humidity mode.
Greatly dehumidifying the room.
Say your system moves air at around 400 cfm per ton.
Running the air conditioner in dry mode helps as it removes the extra humidity in the air.
Your air conditioner will be effective at controlling humidity only if it is correctly sized for the amount of work it needs to do.
In this case the dry mode is useful.
This surely is an electricity saving option during high humidity days as even the fan motor is running at a slow speed and even the compressor.
Cool mode is the regular mode of most air conditioners and does not decrease the humidity in the air but the temperature of the room.
When your air conditioner is in dry mode the device s fan and inner components are running but the unit is not blowing out cold air.
The fan operates at a low speed while the compressor runs for shorter periods of time to ensure that humidity from the air is completely removed.
The drier air fills the room or area where the air conditioner is located.
For example a window unit that s designed for a small room such as a home office will not function properly in a large master bedroom or great room.
In hot humid climates like ours you want your air conditioner to move air at a rate at or near 350 cfm per ton.
Dry mode doesn t really cool the room and the cooling effect comes from the removal of excess moisture from the air.
Many systems are set up to move air at a rate faster than that.
Instead air passes through the device humidity condenses on the unit s evaporator and drier air exits the device.