The unit itself is pretty good at trapping and filtering particles and mold spores. It's easy to use, compact and powerful enough for a (small) space and well built. It's not the quietest device, but I compare it to white noise, so I have no complaints in that area. However, it is almost impossible to find affordable replacement filters. This is simply unacceptable for a machine that is not currently being phased out or discontinued. Filters must be easily accessible. Period.