Air Lock

Airlocks are an architectural device that helps implement heating, ventilation, and air conditioning (HVAC) control of air classification or quality. Their purpose is to allow a shift between cleanliness levels, for example, from ISO 8 to ISO 7 or Grade C to B.an intermediate chamber with two airtight doors or openings to permit passage between two dissimilar spaces (such as two places of unequal atmospheric pressure) : a stoppage of flow caused by air being in a part where liquid ought to circulate.