Convertible, laminar flow biological safety cabinet apparatus

Claim 1

Biological safety cabinet apparatus, comprising: upright cabinet structure including means defining a continuous air path allowing recirculation of air within the cabinet structure, a work compartment defining a portion of said path and located and arranged for generally vertical, downwardly directed airflow therethrough, a fresh air inlet communicating directly with said compartment, and an air discharge outlet; means presenting a generally horizontally disposed work surface positioned within said compartment and adjacent said air inlet; filter means located directly beneath said work surface for removing contaminants from air traveling along said path and preventing discharge of said contaminants through said outlet; fan means below said filter means for pulling ambient air into said air path through said inlet and moving air along said path; air diffuser means above said work surface and located in said air path for creating generally vertical laminar flow of air throughout the entirety of said compartment; and movable damper means adjacent said outlet for simultaneously varying the amount of air discharged from the outlet, the amount of fresh air introduced through said inlet, and the laminar flow characteristics of the air traveling through said compartment.