The Shark air purifier is the best! I have the smaller one in my office, so it only made sense to get a larger one for my home. It is super easy to install the HEPA filter and begin using it. Everyone in my household has allergies, so I love that it allows me to see a breakdown of viruses, bacteria, smoke, pollen, and mold in the air. As soon as you turn it on it scans the air quality and lets you know how clean the air is. It is best to keep it on automatic to adjust itself accordingly to the changing air quality. Do yourself a favor and purchase this!