The Broan-NuTone single-room Air Purifier (model BNAP-100) employs True HEPA filtration and emits no ozone during operation, according to its manufacturer. When the unit’s sensors detect TVOCs or particulates the size of respiratory droplets, dust, and pollen, the fan speed automatically increases to remove them, then switches back to maintenance speed once the air is clean. In addition, the surface of the unit’s filter is treated by a built-in ultraviolet light. It retails for approximately $350.