It's probably mold. You can buy chemicals that are added through the intake that might fix it.
A smell coming from a reverse cycle air conditioner may be a signal that the filter needs to be cleaned. A smell like engine exhaust might be present if the air conditioner motor is in need of repair.
Depends on the smell. What does it smell like?
sounds like your air conditioner compressor is bad.
heater core
It means that, your air conditioner isn't gas powered, so oftentimes people are concerned about where this type of smell could be coming from. However, there are fluids in the engine and other parts of your air conditioner which can leak out, causing this exhaust fume odor.
Any time an air conditioner smells I tell people to try changing the in cabin air filter. most cars its behind your glove box and not costly. good luck.
Air conditioner drain line stopped up or windshield seal leak that covers 99% of the reasons
An air conditioner should not smell like smoke when turned on (or when turned off). I would have to suspect that the electrical insulation is burning.
It sounds like there is a leak inthe evaporator section of your air conditioner. If this continues, the air conditioner will no longer cool and you may have to replace several components of the system. The smell is that of atomized esther oil.
because you have too many dead babies in your air conditioner tank
Freon mixed with refrigerate oil will have a slight smell.................
Failed compressor