Your window air conditioner has a chemical smell what is it?

The most common odor problem from a window ac unit is that there is a buildup over time in the drip pan. The pan collects condensation and allows it to drain through a hole in the ac unit. Over time the pan will collect dirt and other particles, and can develop mold. With the ac unit unplugged the cover will need to be removed, and the pan scraped out and washed.