Air dehumidifiers; air exchangers for cleaning and purifying air; air filters for heating, ventilating, and air conditioning (HVAC) systems for residential and commercial buildings; air flow diffusers; air handlers; air humidifiers; air purifying units for commercial use; air purifying units for industrial purposes; air purifying units for medical use; air sterilizers; air-handling units; dampers, namely, control devices used in air ducts to regulate the flow of air; air filtration units; air...