we got the shark air purifier 2 weeks ago, and already feel the difference in the home, we placed it in the living room, and watched the air get cleaner through out the day, the freshness and the smell is so much pure, we have been sick and using this has not only helped us moving around more, but we can feel better with our breathing. It did not take long at all to see and feel fresh and circulating air through out the home, we are starting to feel better again and enjoying waking up to fresh and crisp clean air.