When I moved into my first place, I couldn't believe how dirty everything was all the time. I found myself dusting and mopping continuously, only to deal with a fresh layer of grime later. After awhile, I realized that the problem was blowing straight out of my air ducts. My ventilation lines were so dirty that it was spreading grime through my house every single time the air clicked on. Fortunately, I called an HVAC contractor who was able to clean my vents to a gleaming shine. I know how big of a difference cleaning up your ventilation system can make, which is why I want to spread the word.