Research towards IAQ based on fresh air random control

In this paper the concentration of CO2 is taken as an index of personnel contamination and the concentration of TVOC as an index of building contamination, which meets the needs of energy saving and indoor air quality improvement through air conditioning fresh air random control.
With the control system, the information of concentration of CO2 and TVOC can be transformed into electric signal then converted into digital signal that will be sent to computer and compared with the given value, and the discrepancy is then changed into electric signal by D/A and sent to controller. According to the discrepancy, controller generates electric signal to drive the motor running and adjust the opening of wind value to actualize the random control of fresh air volume. The principle of the control system and relating researches, are presented too in that paper.