EVANSTON, Ill. — ProMark Associates is known for engineering highly effective clean-air solutions for large commercial businesses and buildings worldwide. Their newest clean-air product is the ProGuard® Mobile Air Purifier. Not to be confused with small portable air filters that are better suited to filtering residential-size rooms, this industrial-grade system can remove particles, volatile organic compounds (VOCs), and pathogens. It can deliver six air changes per hour (recommended by the ASHRAE trade group) in a room of up to 1,500 square feet. The Mobile Air Purifier is powerful, quiet, and can be easily rolled into place on its casters.