Patent ID: 7448144

Claim:
An apparatus for treating air exhausted from an agricultural building to reduce the concentration of unwanted gases in the air, comprising: an enclosed housing, having: an inlet for receiving air exhausted from an agricultural building; a discharge outlet; a plurality of generally horizontally-oriented trays positioned generally parallel to one another in a vertically spaced-apart arrangement within the housing to define an air pathway through the housing with a plurality of generally parallel horizontal segments positioned in an alignment with turns between the parallel segments to direct air from one horizontal segment to the next and upwardly to the discharge outlet; porous liners within the trays, biofilter air treatment material positioned on the porous liners in the plurality of trays so that agricultural building air is exposed to the air treatment material as it moves through the pathway and through the trays; and mounts for removably supporting the trays within the housing enabling the removal of the trays and replacement of the biofilter air treatment material, an irrigation system, having: an irrigation inlet for connection to a moisture source; at least one moisture distribution member for irrigating the biofilter air treatment material; at least one moisture sensing device for monitoring the moisture level of the biofilter air treatment material and providing control signals as a function of the moisture level; a conduit from the irrigation inlet to the at least one moisture distribution member; and a flow control member connected to the moisture sensing device for controlling the flow of moisture from the irrigation inlet to the at least one moisture distribution device in response to the control signals, to maintain a moisture level in the biofilter air treatment material.