My experience with Alen air was great. The representative I chatted with helped me select which unit to get for my specific needs and my order arrived within a couple days. It was easy to unpackage and set up. I like the auto mode with the sensor. It started out with red and now it mostly stays blue so I know it’s working. The dust in my home was driving me crazy and now when the sun shines in I can tell it is significantly less. Overall, great purchase.