i thought if you have the heat on it draws heat from the engine bay and into the cabin. if you close the vents does it still?

 

isnt there a fan that draws the heat in?

 

My car doesn't overheat when I turn my heat on.

 

there is 2 modes. The interior heat and exterior heat (hence the logo). The exterior heat is warmed up thru your heater core then ran thru a blower and out the vents.

Switching to interior heat just circulates the heat in the car and doesn't go thru your heater core.

 

what if there's no heat inside the car?

 

i never understood why one would recirculate heat (minus the A/C).

 

Then you circulate cold air :P If you notice in the cooler climates people have a tendency to use this mode and you end up with foggy windows. The best way is to pull the air from outside and set your temp just to the warm souch and then point it to the floors and vents and your car should almost never fog up.

 

:werd:

it still gets hot inside on recirc, Hence when its freezing out recirc truns on automatically

 

I use the re-circ when there is somthing stinky outside like diesel exahust or dead animal or whatever.

I think the air does go back through the heater core to get re-heated on Recirc.

 

Your car has a heater core. Engine coolant circulates through it, and the ventilation system puts air through it to pick up heat from the engine coolant. It works like an invese liquid-to-air intercooler. Instead of the air going through it putting heat into the coolant, the air takes heat out of the coolant and then is pumped into the cabin. Turning on the heat always passes air through the heater core. If you take in fresh air, you suck outside air through the heater core then into the car, and the recirculate sucks air from inside the car, passes it through the heater core, then puts it back into the car. Skipping the heater core wouldn't accomplish much of anything.