A method for operating a fuel-operated vehicle heater, wherein after receipt of a switch-off signal by a control unit of the fuel-operated vehicle heater, a shutdown phase is initiated, during which remaining fuel present in the fuel-operated vehicle heater is combusted, and wherein a restart phase is initiated by the control unit after receipt of a switch-on signal during the shutdown phase, without the shutdown phase being terminated after complete combustion of the remaining fuel.

A device and method select an optimal boiler combustion model from among a plurality of boiler combustion models for boiler combustion to update a memory in which the boiler combustion models are stored. The device includes a memory configured to store first boiler combustion models that are derived in advance and second boiler combustion models that are derived in advance; and a processor configured to select an optimal boiler combustion model from among the first and second boiler combustion models and to update the memory according to characteristics of the selected optimal boiler combustion model. The processor may further generate a third boiler combustion model for the combustion of the boiler to select the optimal boiler combustion model from among the first to third boiler combustion models and verification data for model verification through the latest data measured in the boiler and data on basic characteristics of the measured data.

An air conditioner for a vehicle includes a cooling water circuit and a heater. The cooling water circuit allows a cooling water to circulate between an engine and a heater core in a heating operation. The engine is a power source of the vehicle. The heater core is configured to heat air using a heat of the cooling water. The heater is located downstream of the engine and upstream of the heater core in the cooling water circuit and is configured to heat the cooling water.

A device and method select an optimal boiler combustion model from among a plurality of boiler combustion models for boiler combustion to update a memory in which the boiler combustion models are stored. The device includes a memory configured to store first boiler combustion models that are derived in advance and second boiler combustion models that are derived in advance; and a processor configured to select an optimal boiler combustion model from among the first and second boiler combustion models and to update the memory according to characteristics of the selected optimal boiler combustion model. The processor may further generate a third boiler combustion model for the combustion of the boiler to select the optimal boiler combustion model from among the first to third boiler combustion models and verification data for model verification through the latest data measured in the boiler and data on basic characteristics of the measured data.

A heating system for heating a vehicle interior of a vehicle having an internal combustion engine by using a heat exchanger includes three temperature sensors, wherein a first temperature sensor measures the coolant temperature at a coolant outlet of the internal combustion engine, a second temperature sensor measures the coolant temperature at a coolant inlet of the internal combustion engine, and a third temperature sensor measures the coolant temperature upstream of at least one heat source. A first heat circuit couples the heat exchanger to the internal combustion engine, whereas a second heat circuit bypasses the internal combustion engine. The first heat circuit operates solely with the internal combustion engine as a heat source when a target inlet temperature of the heat exchanger is above a preset value; otherwise an additional heat source is switched in, optionally operating in addition to the internal combustion engine.

A method for operating a fuel-operated vehicle heater, wherein after receipt of a switch-off signal by a control unit of the fuel-operated vehicle heater, a shutdown phase is initiated, during which remaining fuel present in the fuel-operated vehicle heater is combusted, and wherein a restart phase is initiated by the control unit after receipt of a switch-on signal during the shutdown phase, without the shutdown phase being terminated after complete combustion of the remaining fuel.

An air conditioner for a vehicle includes a cooling water circuit and a heater. The cooling water circuit allows a cooling water to circulate between an engine and a heater core in a heating operation. The engine is a power source of the vehicle. The heater core is configured to heat air using a heat of the cooling water. The heater is located downstream of the engine and upstream of the heater core in the cooling water circuit and is configured to heat the cooling water.

A plug-in hybrid electric vehicle has an internal combustion engine with a coolant outlet connected to a coolant inlet of a fuel operated heater and wherein a coolant outlet of the fuel operated heater is connected to a coolant inlet of an HVAC heater, a coolant outlet of the HVAC heater further being connected to a coolant inlet of the internal combustion engine. The vehicle also has a temperature sensor at the coolant outlet of the internal combustion engine and a temperature sensor at the coolant outlet of the fuel operated heater. The vehicle has a three way valve arranged between the coolant outlet of the HVAC heater and the coolant inlet of the internal combustion engine such that there is a connection between the coolant outlet of the HVAC heater and the coolant inlet of the fuel operated heater, the connection bypassing the internal combustion engine.