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 ...