Air conditioning units are exposed to a great deal of contaminants throughout their everyday usage, simply due to the nature that they filter the air that passes through them as they cool it down. Because of their excessive exposure to a wide variety of different particles and materials, air conditioning units can develop specific odors which they can then blow throughout your home, which can be extremely uncomfortable. Thankfully, there are a few things that you can do to troubleshoot specific odors and identify the problem within your air conditioning unit so that you can fix it as soon as possible and get your house smelling nice again.
A musty or earthy smell coming out of your vents whenever your air conditioner is turned on can be attributed to some sort of mold or mildew growth. The source of the mold can either be in the condenser coils of your air conditioner itself, which usually points to damage or blockage to the condensation drain line, or within your home's ductwork, which is usually caused by improper insulation or a water leak. In either case, you should have an HVAC professional come in to inspect both your central unit and the ducts to find the source of mold and fix the problem as soon as possible, as exposure to mold spores can be a serious health hazard.
A smell of burning is usually caused by some sort of mechanical problem within your air conditioner condenser or fan. If you smell a constant smell of burning in your home that can't be attributed to a candle or some other source, you should turn your air conditioner off immediately to avoid further damage and the risk of a fire. Walk around your air conditioner and look for any signs of burning or the smell of burning, and contact a professional to take a look at your unit.
Rotten Egg Smell
If your air conditioner kicks in and carries the smell of rotten eggs with it, the issue doesn't actually lie with your air conditioning system. Instead, you most likely have some sort of issue with your furnace or natural gas line, and the leak is being pumped throughout your home through your AC's ductwork. This is not to say that this is not a serious issue: a natural gas leak is a serious safety hazard, and you should immediately turn off your air conditioner and open the windows to your home to prevent an explosion. You should call your gas company right away to have your system looked at and the leak fixed.
For more information, contact a company like Custom Comfort.