A/C evaporator issue I would recommend BG FrigiClean to remove excessive odors / cigarette & cigar odor.
Best product to clean evaporator coils IMO. FriClean first followed by FrigiFresh.
Have also sprayed Lysol scented disinfectant ( I used Linen scent) into the fresh air intake to remove stale air smell temporarily.
https://www.bgprod.com/catalog/clima...g-frigi-clean/
And
https://www.bgprod.com/catalog/clima...g-frigi-fresh/
On Amazon
https://www.amazon.com/Frigi-Clean-E...s%2C111&sr=8-1
Also used Nextzett 96110515 Klima-Cleaner Air Conditioner Cleaner - 10 fl oz not as effective as FrigiClean.
https://www.amazon.com/nextzett-9611...s%2C111&sr=8-5