My husband and I never talked about air quality. It’s not something that I had ever really considered and I doubt he had ever really considered it either. It’s not like the house stank or anything. This house had a fairly decent HVAC system in it when we bought and moved into it a few years ago and we had it regularly serviced. We knew it would eventually need to be replaced but that was a given. We bought the cheapest air filters for our HVAC system, not really knowing any better and not questioning it, and our HVAC technician never said anything about the inefficiency of them. Neither my husband nor I are susceptible to allergies or viruses, so we had no complaints. Then our baby girl was born. And she had terrible allergies and allergy related asthma and suddenly good air quality took on a whole new meaning to us. The first thing we did was buy a brand new HVAC unit a few years sooner than we really needed to, but we also wanted to have installed a whole house air purification system with UV lights. We learned that the UV lights will kill viruses, bacteria and mold that get into the HVAC system. We also had the ductwork cleaned and a few places needed to be sealed. We also now only use HEPA filters. They filter close to 100% of allergens that get into the system. Our daughter breathes well at home and rarely needs her nebulizer. Good air quality has become extremely important to us.