Patent ID: 9285136
Filing Date: 2016-03-15
CPC Classification: B01D,F24F

Claim Text:
1. A filter assembly for separating particulate matter entrained in a moving air stream, and carried by a filter holding frame at a duct opening of a building HVAC duct, said filter assembly comprising: a flow-through three dimensional filter frame including a plurality of joined side walls adapted to reside closely adjacent the filter holding frame at the duct opening, and having first and second opposing open faces, said first open face being positioned towards an outside of the HVAC duct and defining a air inlet into which the moving air stream is drawn, and said second open face being positioned towards an inside of the HVAC duct and defining a air outlet from which the moving air stream passes, and wherein at least one of said joined side walls is inwardly angled from said first open face to said second open face, such that said air inlet is larger than said air outlet, and whereby said joined side walls cooperate to form said air outlet at a point inside the HVAC duct and spaced apart from the filter holding frame; and a filtration medium supported within said filter frame and extending between said joined side walls and from said first open face to said second open face, whereby said filtration medium resides between said air inlet and said air outlet in fluid-filtering relation to the moving air stream, and wherein a surface area of said filtration medium at said air inlet is greater than a surface area of said filtration medium at said air outlet.