4. How can I tell if air is being sucked into the filter if there isn’t a place on the unit where you feel suction?

Air moves through the air purifier by means of a fan.  The purifier has been specifically designed to utilize this fan to maximize the air velocity discharging from the unit and to minimize the energy the fan uses to pull air into the filter.  This is done by use of a large open area in the screens through which air passes before it goes through the filter.  Simply stated, air cannot come out of the unit unless it passes through the screens and the filter.  If you feel air coming out of the louvre, it has passed through the filter.