First off, when my car heats up I can smell antifreeze inside and the windshield will fog up and then clear. I am aware that this is most likely the heater core, but my question is once I turn the heat off (blower) it keeps coming out of the defrost vents.

Thanks for your help. I did a search, but my results were inconclusive.

 

It can't be anything but the heater core.

 

OK, so simply replacing the heater core should stop there heat from coming out of the defrost vents? The blower is off, but it still comes out like it is on low or something.

 

The blower may be off, but steam will still leak from the heater core and rise through the defroster vents.