Vehicle air conditioning system

A vehicle air conditioning system, comprising:

• a humidity controlling device having an adsorption portion containing an adsorbent configured to adsorb moisture at a temperature lower than or equal to a predetermined temperature and to desorb the moisture when the temperature exceeds the predetermined temperature, and a heating means configured to heat the adsorption portion;
• a duct having the humidity controlling device provided therein and allowing air from a vehicle interior or a vehicle exterior of a vehicle to flow therethrough, the duct having a first flow path for allowing the air to flow into the vehicle interior on a downstream side of the humidity controlling device and a second flow path for discharging the air to the vehicle exterior;
• a valve configured to switch the flow of the air between the first flow path and the second flow path;
• a blower for feeding the air to the humidity controlling device;
• a control unit configured to control the humidity controlling device, the valve and the blower,
• wherein a control mode of the control unit includes:
• an adsorption mode in which the blower is activated and the air is allowed to flow into the first flow path without activating the heating means;
• and a regeneration mode in which the blower and the heating means are activated and the air is allowed to flow into the second flow path, and
• the control unit executes the regeneration mode when the following conditions (1) and (2) are satisfied:
• (1) an external power source is connected to the vehicle;
• and
• (2) radio waves are received from an electronic key carried by a user of the vehicle or there is at least one occupant in the vehicle interior.