Patent ID: 7766734

Claim:
A zone control exhaust terminal comprising: a housing having a first opening coupled to a duct or open to a shaft and a second opening associated with an area to be ventilated, said housing directing airflow from an inlet associated with said area to be ventilated along a predetermined path to an outlet; a damper hingeably coupled to said housing for controlling airflow between said area and a fan or ventilator; a motor for driving said damper from a closed position at which said damper becomes situated in said predetermined path and an open position at which said damper permits airflow from said inlet, along said predetermined path, and to said outlet in response to a motor control signal in order to ventilate said area to be ventilated; and an airflow regulator situated in said predetermined path, said airflow regulator regulating airflow along said predetermined path from said inlet to said outlet at a first predetermined, non-zero constant rate when said damper is in said closed position in order to ventilate air away from said area to be ventilated by directing air away from said area to be ventilated as said airflow is regulated by said airflow regulator; said airflow regulator regulating said airflow passing therethrough at said first predetermined, non-zero constant rate by passively responding to dynamic fluctuations in duct pressure; wherein, when said damper is in said closed position, said airflow passes through a portion of a cross-sectional area of said housing containing said damper at said first predetermined, non-zero constant rate, and when said damper is in said open position, said airflow passes through said cross-sectional area of said housing at a second, higher airflow rate; and wherein said airflow regulator is situated in at least one of: (i) said damper or (ii) said duct, which is located downstream of said damper.