The Ionic Pro 250 was the only purifier we tested that really lived up to its claim of being “totally silent,” even at its highest setting. But the lack of a hum turned out to be a problem, as it made it almost impossible to tell if the unit was actually working.
The Ionic Pro’s interface is simple, with a power button and three speed settings labeled low, medium, and high. The purifier also has an ion setting, but unlike every other purifier we tested, there’s no icon or symbol to indicate what this setting does.
After some research, we determined that it turns on an ozone function. Given how little information was available about this purifier, we were surprised to find that the Ionic Pro boasts a full onboard three–stage filtration system: pre–filtration, main filter, and carbon filter.
All those filters made for a bulky machine that took up more space than most, but our testing showed it had one of the best air–cleaning abilities of any purifier we tried. It’s also notable for having no visible vents.