Daimlerchrysler Corporation

Chrysler Group LLC

Daimler Ag

Lance C Tagliapietra

Barry J Lake

Lawrence Ziehr

Christopher A Tuckfield

Alfred Jeckel

Mark Bigler

Mark Hill

Curt O'Donnell

David A Barwin

Richard Harris

Holgar Krah

A system for controlling air-conditioning in a vehicle includes an input, a sensor, a first offset module, and an evaporator temperature control module. The input receives an input temperature. The first sensor measures a first dewpoint temperature of air adjacent to a windshield of the vehicle. The first offset module generates a second dewpoint temperature based on the input temperature and generates a first offset based on the first and second dewpoint temperatures. The evaporator temperature control module generates a target evaporator temperature based on the first offset.

Efficient AC operation using dew-point temperature

A system for controlling air-conditioning of a vehicle includes an input, an offset generator module, and an evaporator temperature control module. The input receives an input temperature. The offset generator module receives a psychrometric parameter of air inside the vehicle and generates offsets based on the input temperature and the psychrometric parameter. The evaporator temperature control module generates a target evaporator temperature based on the offsets.

An air-flow management system for controlling the supply air to a motor vehicle passenger compartment is disclosed. The air-flow management system includes a reversible heat pump system for transferring heat energy between an outside environment and a refrigerant. Air from the outside environment, fresh air, and from the passenger compartment, recirculated air, is forced through the air-flow structure by a blower resulting in the transfer of heat energy between the refrigerant and the passenger compartment. A recirculation door provides a means for controlling the mixture of fresh air to recirculated air that flows through the air-flow structure. The position of the recirculation door is selectable by a controller to prevent fogging during the transition from cooling mode to heating mode, minimize the energy expended conditioning the passenger compartment air, and prevent the backflow of unconditioned outside air from the fresh air duct into the recirculation duct.

Air handling controller for HVAC system for electric vehicles

A reversible HVAC system for heating a passenger compartment of a motor vehicle is disclosed. The HVAC system includes a heat pump and an electric heater for supplying heat directly to air blown into the passenger compartment. A controller initially selects the heat pump to provide the heat that is directed into the passenger compartment. The heat pump attempts for a predetermined period of time to heat the passenger compartment to a target temperature. The controller stores a heat pump gain value representing the heating capacity of the heat pump before switching the heating operation to the electric heater. During operation of the electric heater, the controller calculates a system heat gain value representing the required heating capacity to maintain the passenger compartment at the target temperature. While the electric heater is operating, the controller continuously modifies the heat pump gain value to reflect changes in the ambient temperature. When the heat pump gain value approximately equals or exceeds the system gain value the controller selects the heat pump to provide heating.

Controller for heating in reversible air conditioning and heat pump HVAC

A control system for controlling a reversible HVAC system of a motor vehicle is disclosed. The HVAC system includes an electric compressor for circulating a refrigerant through a heat pump. The speed of the compressor is controlled by a compressor control signal having a variable duty cycle. Inside and outside heat exchangers transfer heat energy between an outside environment and a passenger compartment of the motor vehicle. A refrigerant flow switching device switches the direction of refrigerant flow towards the inside heat exchanger in a heating mode and towards the outside heat exchanger in a cooling mode. A pressure reducing assembly supplies pressure reduced refrigerant to the inside heat exchanger in the cooling mode and to the outside heat exchanger in the heating mode. The pressure reducing assembly includes an electronic expansion valve in which the flow rate is set by an EXV control signal having a variable duty cycle. A controller controls the duty cycle setting of the compressor control signal and the EXV control signal such that a desired quantity of heat is transferred between the outside environment and the passenger compartment.

Controller for reversible air conditioning and heat pump HVAC system for

A method of controlling fogging in vehicles having a reversible HVAC system. First, the method detects if conditions for fogging exist such as moisture or localized coldspots on the inside heat exchanger. Then, the speed of the compressor is gradually increased, causing the discharge temperature of the refrigerant to increase at a controlled rate. As the temperature of the refrigerant increases, the temperature of the inside heat exchanger increases. Moisture that exists on the inside heat exchanger slowly begins to evaporate into the air passing through the heat exchanger into the passenger compartment. The moisture laden air flows through the passenger compartment and exits through door seal cracks and outlet vents to the outside environment. After a predetermined period of time, the moisture on the inside heat exchanger has evaporated, so the compressor speed is increased to its steady-state speed.

Growing community of inventors

Winona, MN, United States of America

Lance C Tagliapietra