After driving my car (97 ssei) and shutting it off and it sits for a while the windows get all fogged up.Im thinking its the heater core but I dont lose any coolant at all I smell it very faintly occasionaly but dont seem to lose any and none on the passenger floor. Is the windows fogging up and the smell something else Im missing.

Could be your AC compressor is shot. The AC is used to keep the HVAC system dry.

Thanks I didnt think of that,I had trouble with the AC in the summer.

I've seen this happen commonly during winter when the floor mats are soaked to the gills or the car has a waterleak.