I have a 2006 Honda Civic Hybird.
When I turn the heater on does it just redirect already-existing heat from the warm engine, or is there actually a separate heater unit that uses energy?

I'm asking because I read about someone who saves gas by never using the AC or the heater.
Someone else said that not using the AC makes sense, but that the heater uses no gas since the heat comes from the engine block.

Need fewer troops to support.
Drive a hybrid.
Best tank 71.65 MPG.

Before this car I spent two years learning hypermiling on my 2004 HCH1.