That was an odd experience. Today, I left work late and was lucky enough to catch a bus right when I got to the stop. Having just missed another bus that drove away just as I was walking towards the stop, this seemed to be a nice break.
Not quite. The second I got on, I was met with a very strong odor. This was right at the front door and hit me immediately. On the way to the middle of the bus, the smell stuck around and remained all the way until I got off. To make matters worse, the air conditioner was on, so the windows were all closed. Luckily, I sort of caught a break because the roads were clear at 6:50pm and the bus I missed picked up most people at the stops ahead already.
What was the smell?
I initially described the smell as "sour" of all things. That is not an adjective I've ever used with smells, but it seemed the most accurate. The overwhelming smell may have overwhelmed my nose because I couldn't smell it after a short time. Instead, it seemed like my throat and airway was being irritated, dare I say, "burned" lightly.
After doing some googling, it turns out that a lot of people have experienced it with air conditioners. One person described the smell as a combination of vinegar and alcohol, which would be more descriptive and accurate than plain "sour".
It turns out that the issue may be related to organic growth inside an air conditioner system. As you may know, the cooling of warm air usually causes condensation. If that water isn't allowed to dry, it may become a great place for bacteria, fungus, mold, etc. to grow.
That's good news because I thought I spent the entire trip smelling diesel exhaust fumes or leaking refrigerant. My fingers were crossed that it was body odor or something "healthier". Organic growth doesn't really qualify as "healthier", but I'll take it.