Heating up the cabin of electric vehicles can be challenging since, in contrast to vehicles with conventional combustion engines, the waste heat available is limited. Therefore, it is necessary to provide high-voltage cabin heater for BEVs and HEVs. As part of the heating, ventilation and air conditioning (HVAC) system and controlled through a high-speed Controller Area Network (CAN) interface, this PTC cabin heater is engineered to increase the temperature of the air stream coming from the blower. It features ceramic PTC components that have very low electrical resistance at low temperatures, allowing full current flow and high heat delivery. At high temperatures, the effect is reversed and less heat is released by shutting down the electricity flow due to the increased resistance of the ceramic stones.  This provides desirable control while also functioning as a basic safety feature that prevents overheating. Additional safety features include an enclosed heater rod for maximum protection against high voltages. Coupled with the enclosed heater rod, the air heater’s fin design facilitates a low pressure drop, enabling the blower to run at lower speeds, which reduces air velocity and noise for the occupants. Combined, the heater rod and fin designs provide the industry’s first dual-zone functionality in a PTC heater, allowing the precise and smooth delivery of individual temperatures for driver and passenger and eliminating the waste caused by single-zone heaters.

As more energy-efficient diesel and hybrid-powered vehicles take to the roads, recent trends toward engines with lower heat rejection rates in production vehicles has progressively reduced the amount of available "waste" heat for compartment heating. In an effort to reduce compartment heat up time while increasing the compartment temperature, a new PTC (positive temperature coefficient) electric heater system has been developed to supplement the performance of current hot water based vehicle heaters.

The PTC supplemental heater system features automatic power adjustment in response to ambient temperature conditions and HVAC fan speed, along with self regulation of the heater temperature. In addition, the power draw of the PTC heater can be matched automatically to the available electrical power level for all vehicle operating conditions.