Indoor air quality (IAQ) has become a very important topic as the COVID-19 global pandemic has continued to evolve. We have learned a great deal about the air we breathe and the precautions we need to take to protect ourselves and those around us from airborne particles that can cause us to become ill. At any given time, particulate matter is suspended in the air we breathe. This particulate can be wet, dry, solid, vapor, or gas — think of dust, spores, pollen, fumes, microorganisms, bacteria, viruses, and bioaerosols, to name a few.