Methods and systems are provided for adjusting a position of an air recirculation valve of a HVAC system to adjust a ratio of ambient to recirculated air routed to an AC evaporator to collect condensed water for water injection into an engine. In one example, a method may include adjusting the position of the air recirculation valve of the HVAC system based on a water level in a water storage tank of the water injection system. Further, the method may include adjusting the position of the air recirculation valve of the HVAC system based on a determined humidity of the ambient air and a determined humidity of the recirculated air.

A humidifying device for a vehicle has a humidity detection part, a blower, a non-water-supply humidifier, and a controller. The humidity detection part detects a humidity in a vehicle compartment. The blower draws, as an intake air, an inside air in the vehicle compartment and an outside air outside the vehicle compartment at a specified ratio and blows the intake air toward the vehicle compartment. The non-water-supply humidifier collects water included in the inside air and supplies a humidified air, which is humidified using the water, toward a specified area in the vehicle compartment. The controller sets the specified ratio between the inside air and the outside air and controls an operation of the non-water-supply humidifier. The controller controls the blower to draw at least the inside air, when the non-water-supply humidifier is operated, and when a humidity in the vehicle compartment is lower than a specified humidity.

A vehicular air-conditioning device includes a blowing port mode door as an air volume regulator that regulates volumes of air-conditioning air blown to a driver seat area, a front passenger seat area, and a rear seat area inside a vehicle compartment, and an air-conditioning controller activated by an activation signal outputted from a body controller in response to opening and closing of a rear seat door during a stoppage of a vehicle system. The air-conditioning controller is capable of operating an actuator for driving the blowing port mode door to blow the air-conditioning air to the rear seat area when an activation switch of the vehicle system is turned on in a state where the air-conditioning control unit has been activated by the activation signal.

A first sensor measures temperature at a first evaporator that cools a first zone. A second sensor measures temperature at a second evaporator that cools a second zone. A controller operates a compressor in a normal cooling mode or a single zone cooling mode. In the normal cooling mode, both the first zone and the second zone are cooled with the compressor operated by the controller in response to temperature measurements from one or both of the first sensor and the second sensor. In the single zone cooling mode, only the second zone is cooled with the compressor controlled by the controller in response to temperature measurements from the second sensor and the controller determining that the first evaporator has a low probability of accumulating frozen moisture on surfaces thereof, and in response to determining a high probability of accumulating frozen moisture on surfaces thereof the compressor is not operated.

A vehicle climate control system has a control strategy which controls temperature of an evaporator in a refrigeration circuit to achieve a target temperature/relative humidity within a comfort zone which is defined by upper and lower temperature boundaries and upper and lower relative humidity boundaries. Several system embodiments are disclosed, including an all-electric system. All systems operate with improved efficiency.

When a refrigerant evaporation temperature of an interior evaporator cannot be set lower than a dew-point temperature of air flowing into the interior evaporator in a heating operation, a refrigerant circuit is switched to a normal heating operation mode in which a flow rate of the refrigerant flowing into the interior evaporator is set to zero by allowing the refrigerant to flow toward a bypass passage. In a case where the air cannot be dehumidified by the interior evaporator, an unnecessary heat exchange between the air and the refrigerant in the interior evaporator can be suppressed. Thus, the energy of the vehicle air conditioner can be effectively prevented from being wasted.

A system is disclosed. The system includes a climate condition determination module that is configured to determine a climate condition associated with a vehicle based upon an external air temperature or a dew point temperature. The system also includes a compressor operational state control module that is configured to control a plurality of operational states of a variable displacement compressor of a heating, ventilation and air conditioning system within the vehicle. The compressor operational state control module is configured to cause the variable displacement compressor to selectively transition from a variable displacement operational state to a fixed displacement-like operational state when the climate condition exceeds a climate threshold to cause an evaporator of the heating, ventilation and air conditioning system to provide evaporator air having an air temperature corresponding to a target evaporator air temperature.

A method for air-conditioning an interior of a vehicle to prevent fogging of the windows when at least one identifiable user enters the vehicle. The vehicle has a vehicle communication device which communicates with at least one user communication unit, a climate detection device for detecting the climate in the interior of the vehicle or for detecting the climate in the interior and in the area surrounding the vehicle, as well as a climate modification device for changing the climate in the interior of the vehicle. The method comprises steps of: checking by means of whether an identifiable user is approaching the vehicle, testing whether a fogging of at least one of the windows of the vehicle is to be expected when the user enters the vehicle, and air-conditioning the interior of the vehicle in such a way that fogging of the windows of the vehicle is prevented.

An air-conditioner may include an evaporator, a compressor configured to compress refrigerant supplied to the evaporator and a clutch configured to transmit power needed to operate the compressor to the compressor or to prevent power from being supplied to the compressor, wherein the clutch prevents power from being supplied to the compressor when an actual measurement temperature of the evaporator reaches a lower limit threshold temperature selected among the lower limit threshold temperature and an upper limit threshold temperature and the lower limit threshold temperature is changeable, and the upper limit threshold temperature is relatively higher than the lower limit threshold temperature and is changeable.

A method is specified for determining information concerning a particle load of an airflow flowing into a vehicle interior. That method includes determining the initial mass of a filter at the start of a time interval, by means of strain gauges, passing an airflow through the filter for a time interval, determining the end mass of the filter at the end of the time interval, by means of strain gauges, ascertaining the mass difference between the end mass and the initial mass of the filter and outputting of information, based on the ascertained mass difference, concerning the particle load of the airflow. An apparatus for ascertaining information concerning a particle load of an airflow flowing into a vehicle interior is also disclosed.