AC/Heater

You can barely smell "Freon" (134a) but it's sorta sweet. But so is antifreeze. You may have a leaky heater core, radiator or hoses, especially if your coolant is going down a little more than usual. And you may be picking up the antifreeze smell from the engine compartment, getting drawn into the heater box. But note that running heater on "Max" uses cabin air only....meaning the heater core is probably not the problem.