Control method for ventilation apparatus

A control method of a ventilation apparatus, the ventilation apparatus comprising a case includes a first common passage through which indoor air or outdoor air flows, a second common passage which is positioned above the first common passage, an indoor suction chamber which is connected to the first common passage and the second common passage and into which indoor air is suctioned, an indoor discharge chamber which is connected to the first common passage and the second common passage and from which air is discharged into an indoor space, an outdoor suction chamber which is connected to the first common passage and the second common passage and into which outdoor air is suctioned, and an outdoor discharge chamber which is connected to the first common passage and the second common passage and from which air is discharged to an outdoor space;

• a first desiccant heat exchanger provided in the first common passage, through which indoor air or outdoor air flows, to absorb or desorb moisture in air;
• a second desiccant heat exchanger provided in the second common passage, which is separate from the first common passage, and through which indoor air or outdoor air flows, to absorb or desorb moisture in air;
• an indoor suction damper provided in die indoor suction chamber into which indoor air is suctioned toward the first common passage or the second common passage;
• an indoor discharge damper provided in the indoor discharge chamber through which air is discharged to the indoor space from the first common passage or the second common passage;
• an outdoor suction damper provided in the outdoor suction chamber into which outdoor air is suctioned toward the first common passage or the second common passage;
• and an outdoor discharge damper provided in the outdoor discharge chamber through which air is discharged to the outdoor space from the first common passage or the second common passage, the method comprising
• measuring outdoor temperature and humidity and indoor temperature and humidity;
• and
• operating the first desiccant heat exchanger and the second heat exchanger in a dry mode, when the measured outdoor temperature and humidity and the measured indoor temperature and humidity are equal to or greater than a set temperature and a set humidity, wherein the dry mode comprises:
• a heat exchanger control operation in which refrigerant output from a compressor is switched, so that one of the first desiccant heat exchanger or the second desiccant heat exchanger which needs to be dried acts as a condenser while the other of the first desiccant heat exchanger or the second desiccant heat exchanger which does not need to be dried acts as an evaporator, and a flow rate control operation which is performed simultaneously with the heat exchanger control operation, and in which a first flow rate of air passing through the one of the first desiccant heat exchanger or the second desiccant heat exchanged is controlled to be less than a second flow rate of air passing through the other of the first desiccant heat exchanger or the second desiccant heat exchanged, wherein, in the flow rate control operation, the first flow rate and the second flow rate are controlled by adjusting each of the indoor suction damper, the indoor discharge damper, the outdoor suction damper, and the outdoor discharge damper, and wherein the flow rate control operation is performed such that the indoor suction damper and the indoor discharge damper are controlled to be closed, whereas the outdoor suction damper and the outdoor discharge damper are controlled to be opened.