Patent ID: 6461233
Filing Date: 2002-10-08
Classification: B08B

Abstract:
An exhaust hood comprising:a cabinet defining a work area, said cabinet having a front face and a rear face, said front face having an opening for providing access to said work area; an exhaust plenum located at said rear face of said cabinet which receives air passing through said work area from said opening, said plenum being coupled with an exhaust outlet, and including a baffle located in front of said rear face and having first structure located at a first plenum zone and second structure located at a second plenum zone, said first zone being located below said second zone, wherein air passing through a lower portion of said opening primarily enters said plenum through said first zone and air passing through an upper portion of said opening primarily enters said plenum through said second zone; and a vertically mounted sash for closing said opening, said sash having an exterior face and an interior face, said interior face being positioned toward said work area, whereby when said sash is raised to a first height air flows primarily across said work area and into said first structure and when said sash is raised to a second height air entering said lower portion of said opening flows primarily across said work area and into said first structure and air entering said upper portion of said opening flows primarily across said work area and into said second structure, thereby resulting in substantially laminar flow of air through said work area, wherein each of said first and second structures includes a plurality of apertures therein, each said aperture having an area, wherein the sum of the areas of all apertures in said first structure is greater than the sum of the areas of all apertures in said second structure.