That must be an option they are looking at for electric conversion trucks? In the third video when they have it installed in the truck they point out the coolant lines that go to the heater box..Around the 6:50-7:20 mark of the middle video he shows and mentions a 400v PTC heater connection. Hopefully they do in fact go forward with the mechanical compressor and standard heater core option. Will get expensive fast if you need 400v.