Air ventilation and exhaust units and systems, namely, fume extraction units, fume extraction systems, particulate extraction units, particulate extraction systems, local air exhaust units, local air exhaust systems, source air capture units, source air capture systems, single air extraction units and systems, central air extraction units and systems, all of the aforementioned units and systems comprising fume extraction arms, fume extraction hoods, hose reels, fans, industrial blowers, dust collectors, fume collectors and mist collectors; air purifying units, namely, portable air purifying units, wall mounted air purifying units, and ceiling mounted air purifying units; air purifying units and system accessories therefor, namely, air filters for domestic use and for industrial installations; air purifying technology and air extraction systems, namely, air purifying units and air purifying apparatus for commercial, domestic, and industrial applications