Being relatively new Arizona residents, we needed to deal with more airborne dust and much different pollens than we were used to. We purchased the PureZone Elite 4-in-1. My wife and I feel we have fewer issues with the desert pollens since we have had this PureZone product running in our house. The HEPA filters are clearly capturing dust that would have been circulating through our home. The fan is very quiet and hardly noticeable. We are very pleased with the performance of the PureZone Elite 4-in-1.