Temperature control

A master controller handles the temperature control in the vehicle interior. The control operation is based on the set nominal value and the calculated actual temperature value. The nominal value is set at the IHKA controls via the temperature dial. The actual value is calculated from the measured temperature of the internal temperature sensor and of the ventilation temperature sensor, as well as the measured value of the solar sensor. The lead parameter results from the comparison of the actual value of the inside temperature with the corrected nominal value.

Compared to the set nominal value, when it is cold the inside temperature is raised so that even at subzero temperatures the climate remains pleasant even with an unchanged temperature setting. The outside temperature is transferred across the body CAN to the IHKA control module.

The ventilation temperature is regulated by the mixing flap in the heater/air conditioner. The air-mass flow is guided through the evaporator. The air-mass flow is cooled and dried (when the air conditioning system is switched on). Subsequently, the mixing flap guides the air-mass flow (depending on the set desired temperature value in the IHKA controls) fully or partially over the heat exchanger for the heating system and the electrical auxiliary heater. Subsequently, the air flows mix once again. The air-mass flow is then guided via the ventilation flaps into the vehicle interior.

The evaporator temperature is regulated with the help of the evaporator temperature sensor and the expansion valve. The evaporator temperature is adjusted to the specified nominal value of 2 °C. Lower temperature are not possible due to the danger of freezing over. The evaporator control is independent of the temperature control in the vehicle interior.