Ventilator

Noun

 * 1) A device that circulates fresh air and expels stale or noxious air
 * 2)  A respirator

Thesaurus
aerator, air conditioner, air cooler, air duct, air filter, air hole, air passage, air shaft, air tube, airway, blower, blowhole, breathing hole, chiller, cold pack, cooler, cooling system, electric fan, exhaust fan, fan, flabellum, ice bag, ice bucket, ice cube, ice pack, ice pail, louver, louverwork, naris, nostril, punkah, shaft, spilehole, spiracle, surface cooler, thermantidote, touchhole, transom, vent, ventage, venthole, ventiduct, ventilating shaft, water cooler, wind tunnel, windcatcher, windsail, windscoop, wine cooler