Chevy Volt HV Eberspächer Heater (Plenty of Heat!)

Passenger compartment heat is pretty straight forward for an ICE. The engine naturally creates a ton of excess heat and this is pumped into the HVAC system to heat the passenger compartment.

Typical ICE engines are only about 20-30% efficient, putting the rest of the energy into heat, noise, and vibration. The high voltage AC drivetrain that I’ll be using is closer to 90-95% efficient, so there will be magnitudes less heat generation.

That leaves me with two options for heating:
– Place high voltage ceramic heaters and fans under the dash. Although this would work, it won’t distribute heat around the car evenly, defrost the windshield, or integrate with the RX8 HVAC system.
– The second, and better, option is to heat fluid and pump it through the RX8 HVAC system. This will allow me to seamlessly integrate the high voltage heater and make the final system appear to be stock.

I decided to go with the superior second option and pick up a 6KW water heater from a Chevy Volt. This will also allow me to keep with my rule of OEM parts, but looks like it will force me to add yet another unique CAN bus to the vehicle architecture plan.