[shane55]

The ac system in modern cars like ours is designed to operate all year round in all conditions with little need for changes by the user, therefore during kickdown or hard acceleration the compressor is temporarily disconnected in order not to hamper acceleration/performance or damage the unit itself.

When the snowflake symbol is lit up the compressor is always running there is no on off cycling like older systems, and as its a variable swashplate the cooling output can be regulated by altering the voltage sent to the actuator. This in turn angles the plate in the compressor which regulates the amount of cooling done by the system. Many factors influence the cooling output including the intensity of sunlight hitting the photo resistor on the dash!

Dehumidifying happens anytime the compressor is running, this simply is because the air is cooled below its dew point. At ambient temperatures below 0 degrees C the outside air is cold and dry enough to provide cooling and dehumidifying requirements to the driver so the ecu shuts off the compressor until the ambient rises.

Turning on and off the system during the year needlessly increases the chance of mould growth on the evaporator and causing smells.

The mist your getting is probably from the heater and evap matrix. When cooling was on, and then turned off, any condensation that formed on the surface of the evaporator that didn't drip off will be sitting between the fins of the coil. When you then need heat the outside air which can already be 'damp' is sucked through the wet evaporator coil then through the hot heater coil...producing a steam room effect!

Best advise is leave the snowflake on all year round and change your micro filter.