Electronic drive trains are extremely efficient, as a result there is not much heat generated during the driving process. As a result EVs need alternative heat sources. The heating process can have a large effect on the range of a EV, as the energy come directly from the battery pack.
PTC (Positive temperature coefficient) heaters are solid state devices electrical heater which strives to keep a constant temperature regardless of how the ambient conditions changes. It is the material in the heater itself that regulates the temperature.
They are designed to be mounted in a HVCA unit in front of the blower fan, in combination with, or replacing, the original heater core.
PTC Heaters come in a variety of operational voltages and controllers. Dedicated EV PTC heaters run off HV, others off 12v and home appliance types run off 120vac.
Many European model cars utilize 12v ptc heaters for preheating the cabin. 12v heaters do not produce large amounts of heat (2kw>) but are still worthy contenders in combination with other heating methods. Dedicated HV EV PTC heaters produce 5kw+ worth of heat.
Water heaters, like PTC heaters, come in a variety of operational voltages. They are a simple solution, as theres no need to dismantle or install anything into a vehicles stock HVAC unit. They can be found in many EVs and hybrid vehicles.
Heat pumps are regarded as the most efficient type of heating in a EV. They function by transferring thermal energy from a cooler space to a warmer space using a refrigeration cycle, think of a AC system operating in reverse.
seat heaters are a efficient way if providing heat in a ev, cheap aftermarket kits are available.