Method for controlling ventilation flow to premises, involves use of high and low flow rates in successive time periods the high rate period being adjusted to raise or lower the required average flow

摘要

During an initial time period (t1) a low fixed flow of ventilating air (q1) is maintained and the percentage of carbon dioxide (M) rises. In a second time period (t2) a high fixed flow of ventilating air (q2) lowers the carbon dioxide level rapidly. The average carbon dioxide level (N) is kept to a constant target by either raising or lowering the second time period as a percentage of the repeated cycles An Independent claim is also included for equipment to capture a measure of pollution level such as number of persons and to use two speed fan and two position valve to produce successive high and low ventilating air flow periods