There was a long period of time when I thought I was sick. I kept coughing, sneezing, and just feeling miserable. I would try to sleep it off but it never seemed to go away. That was until I stepped outside for various reasons. I began to realize that the fresh air was doing me good. I even felt better when I was at work than when I was at home. I went to a doctor about my issues once and the doctor asked me about my HVAC equipment. He asked if I was changing my air filters and if I used an air purifier at all. I never used air purifiers and I admittedly didn’t change the air filters very often. I would wait until they actually looked dirty to me. I didn’t realize until later that it’s not always easy to see that an air filter is clogged because of all those microscopic contaminants. They do obstruct the flow of air with your HVAC system though and they will cause the HVAC system to struggle. My HVAC indeed was struggling, but it never died on me. I should have noticed that after I changed the air filter, the HVAC would run more smoothly and the air quality would improve to some degree. Well, I ended up having my ductwork cleaned, a new air purification system installed, and I used better air filters. I also changed them on time as per the instructions. I was suddenly feeling way better and I no longer felt sick inside my home any longer. I wish I would have kept on top of air filter changes and ductwork cleaning before. Also, the air purification system has worked like a dream and I couldn’t imagine not using it anymore.